2024
Amico, E.; Serpieri, J.; Iuso, G.; Cafiero, G.
Flow topology of deep reinforcement learning drag-reduced bluff body wakes Journal Article
In: vol. 36, no. 8, 2024, ISSN: 1089-7666.
@article{Amico2024,
title = {Flow topology of deep reinforcement learning drag-reduced bluff body wakes},
author = {E. Amico and J. Serpieri and G. Iuso and G. Cafiero},
doi = {10.1063/5.0217692},
issn = {1089-7666},
year = {2024},
date = {2024-08-01},
volume = {36},
number = {8},
publisher = {AIP Publishing},
abstract = {The wake topology of a bluff body, representative of a commercial road vehicle, manipulated by different control laws for pulsed jets located at the trailing edges of the model is presented and discussed. The parameters of the control laws have been identified through previous work, in which a deep reinforcement learning (DRL) algorithm was trained under different conditions to achieve drag reduction first and also taking the energy budget into account. The focus of this work is to understand the mechanisms through which the DRL agent can reach the objective in four distinct cases, with different sizes of the state and reward definition. Planar and stereoscopic particle image velocimetry measurements were carried out at different planes in the body's wake. The findings suggest that, when large drag reduction conditions are achieved, the recirculating flow bubble is shortened in the streamwise direction, the wake becomes symmetrical in the streamwise-vertical plane at the symmetry station along the cross-stream direction, and there is a substantial pressure recovery at the base of the model. In these conditions, the wake topology drastically changes with respect to that of the natural case. Conversely, when the energy budget is introduced, the modification of the recirculating flow bubble is smaller as a consequence of the reduced actuation. This study, thus, while complementing previous work with flow physics analyses, gives valuable insights on the wake topologies to aim for when targeting pressure drag reduction through active flow control strategies. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Zaccara, Mirko; Paolillo, Gerardo; Cafiero, Gioacchino; Astarita, Tommaso; Iuso, Gaetano; Cardone, Gennaro; Greco, Carlo Salvatore
Near field evolution of wingtip vortices under synthetic-jet based control Journal Article
In: Aerospace Science and Technology, vol. 148, 2024, ISSN: 1270-9638.
@article{Zaccara2024,
title = {Near field evolution of wingtip vortices under synthetic-jet based control},
author = {Mirko Zaccara and Gerardo Paolillo and Gioacchino Cafiero and Tommaso Astarita and Gaetano Iuso and Gennaro Cardone and Carlo Salvatore Greco},
doi = {10.1016/j.ast.2024.109068},
issn = {1270-9638},
year = {2024},
date = {2024-05-00},
journal = {Aerospace Science and Technology},
volume = {148},
publisher = {Elsevier BV},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Grava, Alessandro; Picillo, Marco; Serpieri, Jacopo; Iuso, Gaetano; Bernardos, Luis; Cafiero, Gioacchino
Aerodynamic investigation of a drone propeller in cross-flow
2024.
@{Grava2024,
title = {Aerodynamic investigation of a drone propeller in cross-flow},
author = {Alessandro Grava and Marco Picillo and Jacopo Serpieri and Gaetano Iuso and Luis Bernardos and Gioacchino Cafiero},
doi = {10.2514/6.2024-0244},
year = {2024},
date = {2024-01-04},
publisher = {American Institute of Aeronautics and Astronautics},
keywords = {},
pubstate = {published},
tppubtype = {}
}
Cafiero, Gioacchino; Amico, Enrico; Iuso, Gaetano
Manipulation of a turbulent boundary layer using sinusoidal riblets Journal Article
In: Journal of Fluid Mechanics, vol. 984, pp. A59, 2024.
@article{Cafiero_Amico_Iuso_2024,
title = {Manipulation of a turbulent boundary layer using sinusoidal riblets},
author = {Gioacchino Cafiero and Enrico Amico and Gaetano Iuso},
doi = {10.1017/jfm.2024.256},
year = {2024},
date = {2024-01-01},
journal = {Journal of Fluid Mechanics},
volume = {984},
pages = {A59},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cafiero, G.; Amico, E.; Serpieri, J.; Iuso, G.
Effects of Sinusoidal Riblets on Turbulent Boundary Layer Flow Structures Book Chapter
In: Springer Proceedings in Physics, pp. 263–268, Springer Nature Switzerland, 2024, ISBN: 9783031559242.
@inbook{Cafiero2024,
title = {Effects of Sinusoidal Riblets on Turbulent Boundary Layer Flow Structures},
author = {G. Cafiero and E. Amico and J. Serpieri and G. Iuso},
doi = {10.1007/978-3-031-55924-2_35},
isbn = {9783031559242},
year = {2024},
date = {2024-00-00},
booktitle = {Springer Proceedings in Physics},
pages = {263--268},
publisher = {Springer Nature Switzerland},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
Ricci, F. M.; Amico, E.; Cafiero, G.; Iuso, G.; Serpieri, J.
Plasma Jets in a Turbulent Channel Flow Book Chapter
In: Springer Proceedings in Physics, pp. 249–255, Springer Nature Switzerland, 2024, ISBN: 9783031559242.
@inbook{Ricci2024,
title = {Plasma Jets in a Turbulent Channel Flow},
author = {F. M. Ricci and E. Amico and G. Cafiero and G. Iuso and J. Serpieri},
doi = {10.1007/978-3-031-55924-2_33},
isbn = {9783031559242},
year = {2024},
date = {2024-00-00},
booktitle = {Springer Proceedings in Physics},
pages = {249--255},
publisher = {Springer Nature Switzerland},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
2023
Wang, Jiabin; Minelli, Guglielmo; Cafiero, Gioacchino; Iuso, Gaetano; He, Kan; Basara, Branislav; Gao, Guangjun; Krajnović, Sinisa
Validation of PANS and effects of ground and wheel motion on the aerodynamic behaviours of a square-back van Journal Article
In: J. Fluid Mech., vol. 958, 2023, ISSN: 1469-7645.
@article{Wang2023,
title = {Validation of PANS and effects of ground and wheel motion on the aerodynamic behaviours of a square-back van},
author = {Jiabin Wang and Guglielmo Minelli and Gioacchino Cafiero and Gaetano Iuso and Kan He and Branislav Basara and Guangjun Gao and Sinisa Krajnović},
doi = {10.1017/jfm.2023.47},
issn = {1469-7645},
year = {2023},
date = {2023-03-10},
journal = {J. Fluid Mech.},
volume = {958},
publisher = {Cambridge University Press (CUP)},
abstract = {This paper presents a numerical investigation of the effects of the moving ground and rotating wheels on the turbulent flow around a 1/10 scaled square-back van model. A comprehensive comparison among the partially averaged Navier–Stokes (PANS), large eddy simulation (LES) and particle image velocimetry (PIV) involving the aerodynamic drag, the wake topology, the velocity and the Reynolds stress profiles in the wake region is conducted. The proper orthogonal decomposition (POD) and fast Fourier transform (FFT) are applied to the shear layers shedding from the trailing edges to comment on the coherent structures and their frequency content. The Reynolds number for both simulations and experiments is set to Re = 2.5 × 105 based on the inlet velocity
${U_{inf}} = 9;textrm{m};{textrm{s}^{ - 1}}$
W = 0.17 m. The results show that PANS accurately predicts the flow field measured in experiments and predicted by a resolved LES, even with a low-resolution grid. The superiority of the PANS approach could provide good guidance for industrial research in predicting the turbulent flow around the square-back van model with affordable computational grids. The ground and wheel motion mechanism on the aerodynamic forces has been revealed by analysing the surface pressure distribution, the wheels’ surrounding flow, the underbody flow characteristics and the turbulent wake structures. The effects of the ground and wheel motion on the frequency, evolution and development characteristics of the wake shear layers are analysed, thus providing relevant insights for future experimental investigations of square-back van models. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Serpieri, J; Hehner, Mt; Pasch, S; Gatti, D; Kriegseis, J
Introducing a Multi-Modal Plasma Actuator for Turbulent Flow Actuation Journal Article
In: AIAA JOURNAL, vol. 61, no. 8, pp. 3707–3712, 2023.
@article{ 11583_2981140,
title = {Introducing a Multi-Modal Plasma Actuator for Turbulent Flow Actuation},
author = {J Serpieri and Mt Hehner and S Pasch and D Gatti and J Kriegseis},
url = {https://arc.aiaa.org/doi/10.2514/1.J062812},
doi = {10.2514/1.J062812},
year = {2023},
date = {2023-01-01},
journal = {AIAA JOURNAL},
volume = {61},
number = {8},
pages = {3707--3712},
publisher = {AMER INST AERONAUTICS ASTRONAUTICS},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2022
Amico, Enrico; Bari, Domenico Di; Cafiero, Gioacchino; Iuso, Gaetano
Genetic Algorithm-based control of the wake of a bluff body Journal Article
In: J. Phys.: Conf. Ser., vol. 2293, no. 1, 2022, ISSN: 1742-6596.
@article{Amico2022,
title = {Genetic Algorithm-based control of the wake of a bluff body},
author = {Enrico Amico and Domenico Di Bari and Gioacchino Cafiero and Gaetano Iuso},
doi = {10.1088/1742-6596/2293/1/012016},
issn = {1742-6596},
year = {2022},
date = {2022-06-01},
journal = {J. Phys.: Conf. Ser.},
volume = {2293},
number = {1},
publisher = {IOP Publishing},
abstract = {Abstract
This work reports on the application of a Genetic Algorithm (GA)-based approach to control the wake of a bluff body. The control is achieved through the actuation of four air jets placed along the edges of the model’s base. The dependence of the population size on the convergence of the genetic code was assessed, evidencing an increase of the number of elements in the population needed to learning more complex tasks. In this case, a sum of two sine waves is considered, where frequency and amplitude of each of the two sine waves are optimised.
It is demonstrated that the GA converges to a control law yielding values of the drag reduction up to 11.2% with respect to the natural case. The cost function has been defined as to minimise the drag coefficient, without accounting for the energy spent in the actuation.
The proper orthogonal decomposition (POD) applied to the fluctuating pressure signals highlights the most relevant features of the wake. The results show that in the natural case nearly 80% of the modal energy is associated with the first mode. Conversely, the forced case features a more evenly distributed energy content across the POD modes.
The analysis of the first two modes reveals that for both cases the wake is governed by the shedding phenomenon. Furthermore, the analysis reveals that regardless of the actuation conditions, the top-down shedding represents the most significant phenomenon for the wake dynamics. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Serpieri, J.; Hehner, M. T.; Kriegseis, J.
Active electrode isolation for advanced plasma actuators Journal Article
In: SENSORS AND ACTUATORS. A, PHYSICAL, vol. 343, 2022.
@article{ 11583_2969433,
title = {Active electrode isolation for advanced plasma actuators},
author = {J. Serpieri and M. T. Hehner and J. Kriegseis},
url = {https://www.sciencedirect.com/science/article/pii/S0924424722003132},
doi = {10.1016/j.sna.2022.113675},
year = {2022},
date = {2022-01-01},
journal = {SENSORS AND ACTUATORS. A, PHYSICAL},
volume = {343},
publisher = {Elsevier B.V.},
abstract = {The current document describes a novel concept for actively isolating neighboring electrodes of multi-electrodes plasma actuators. For these actuators, such as the phased-array actuators (Corke and Matlis 2000) or the oscillating-wall ones (Choi et al. 2011), at different time instants, different sets of electrodes are operated; meanwhile the not-operated electrodes are floating grounds for the circuit. The proposed concept consists of splitting the amplitude of the voltage signals supplied to the operated electrodes and needed to generate the plasma discharge in a baseline signal and a time-modulated component. While the first is to be continuously supplied to all electrode sets and is of amplitude below the breakdown voltage for the considered fluid and plasma actuator, the latter, supplied only to the operated electrodes, has an amplitude such that, when superimposed to the baseline voltage, leads to the plasma discharge. The proposed operation reduces the voltage difference between operated and not-operated neighboring electrodes. Therefore, related detrimental interactions, such as parasitic discharges, are prevented. Two proof-of-concept experiments are performed and presented showing the proposed operation mode effective and efficient.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The current document describes a novel concept for actively isolating neighboring electrodes of multi-electrodes plasma actuators. For these actuators, such as the phased-array actuators (Corke and Matlis 2000) or the oscillating-wall ones (Choi et al. 2011), at different time instants, different sets of electrodes are operated; meanwhile the not-operated electrodes are floating grounds for the circuit. The proposed concept consists of splitting the amplitude of the voltage signals supplied to the operated electrodes and needed to generate the plasma discharge in a baseline signal and a time-modulated component. While the first is to be continuously supplied to all electrode sets and is of amplitude below the breakdown voltage for the considered fluid and plasma actuator, the latter, supplied only to the operated electrodes, has an amplitude such that, when superimposed to the baseline voltage, leads to the plasma discharge. The proposed operation reduces the voltage difference between operated and not-operated neighboring electrodes. Therefore, related detrimental interactions, such as parasitic discharges, are prevented. Two proof-of-concept experiments are performed and presented showing the proposed operation mode effective and efficient.
Amico, E.; Cafiero, G.; Iuso, G.
Deep reinforcement learning for active control of a three-dimensional bluff body wake Journal Article
In: Physics of Fluids, vol. 34, no. 10, pp. 105126, 2022, ISSN: 1070-6631.
@article{10.1063/5.0108387,
title = {Deep reinforcement learning for active control of a three-dimensional bluff body wake},
author = {E. Amico and G. Cafiero and G. Iuso},
url = {https://doi.org/10.1063/5.0108387},
doi = {10.1063/5.0108387},
issn = {1070-6631},
year = {2022},
date = {2022-01-01},
journal = {Physics of Fluids},
volume = {34},
number = {10},
pages = {105126},
abstract = {The application of deep reinforcement learning (DRL) to train an agent capable of learning control laws for pulsed jets to manipulate the wake of a bluff body is presented and discussed. The work has been performed experimentally at a value of the Reynolds number Re∼105 adopting a single-step approach for the training of the agent. Two main aspects are targeted: first, the dimension of the state, allowing us to draw conclusions on its effect on the training of the neural network; second, the capability of the agent to learn optimal strategies aimed at maximizing more complex tasks identified with the reward. The agent is trained to learn strategies that minimize drag only or minimize drag while maximizing the power budget of the fluidic system. The results show that independently on the definition of the reward, the DRL learns forcing conditions that yield values of drag reduction that are as large as 10% when the reward is based on the drag minimization only. On the other hand, when also the power budget is accounted for, the agent learns forcing configurations that yield lower drag reduction (5%) but characterized by large values of the efficiency. A comparison between the natural and the forced conditions is carried out in terms of the pressure distribution across the model's base. The different structure of the wake that is obtained depending on the training of the agent suggests that the possible forcing configuration yielding similar values of the reward is local minima for the problem. This represents, to the authors' knowledge, the first application of a single-step DRL in an experimental framework at large values of the Reynolds number to control the wake of a three-dimensional bluff body.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The application of deep reinforcement learning (DRL) to train an agent capable of learning control laws for pulsed jets to manipulate the wake of a bluff body is presented and discussed. The work has been performed experimentally at a value of the Reynolds number Re∼105 adopting a single-step approach for the training of the agent. Two main aspects are targeted: first, the dimension of the state, allowing us to draw conclusions on its effect on the training of the neural network; second, the capability of the agent to learn optimal strategies aimed at maximizing more complex tasks identified with the reward. The agent is trained to learn strategies that minimize drag only or minimize drag while maximizing the power budget of the fluidic system. The results show that independently on the definition of the reward, the DRL learns forcing conditions that yield values of drag reduction that are as large as 10% when the reward is based on the drag minimization only. On the other hand, when also the power budget is accounted for, the agent learns forcing configurations that yield lower drag reduction (5%) but characterized by large values of the efficiency. A comparison between the natural and the forced conditions is carried out in terms of the pressure distribution across the model’s base. The different structure of the wake that is obtained depending on the training of the agent suggests that the possible forcing configuration yielding similar values of the reward is local minima for the problem. This represents, to the authors’ knowledge, the first application of a single-step DRL in an experimental framework at large values of the Reynolds number to control the wake of a three-dimensional bluff body.
2021
Cerutti, Juan; Cafiero, Gioacchino; Iuso, Gaetano
Aerodynamic drag reduction by means of platooning configurations of light commercial vehicles: A flow field analysis Journal Article
In: INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 2021.
@article{ 11583_2907092,
title = {Aerodynamic drag reduction by means of platooning configurations of light commercial vehicles: A flow field analysis},
author = {Juan Cerutti and Gioacchino Cafiero and Gaetano Iuso},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0142727X21000539},
doi = {10.1016/j.ijheatfluidflow.2021.108823},
year = {2021},
date = {2021-01-01},
journal = {INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cafiero, Gioacchino; Amico, Enrico; Iuso, Gaetano
Deep reinforcement learning based control of the wake of a bluff body Conference
Bulletin of the American Physical Society, American Physical Society, 2021.
@conference{ 11583_2957506,
title = {Deep reinforcement learning based control of the wake of a bluff body},
author = {Gioacchino Cafiero and Enrico Amico and Gaetano Iuso},
year = {2021},
date = {2021-01-01},
booktitle = {Bulletin of the American Physical Society},
publisher = {American Physical Society},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Amico, Enrico; Cafiero, Gioacchino; Iuso, Gaetano
Deep Reinforcement Learning for active flow control of the wake of a bluff body Conference
XXIX A.I.VE.LA. National Meeting, Online, 2021.
@conference{ 11583_2957502,
title = {Deep Reinforcement Learning for active flow control of the wake of a bluff body},
author = {Enrico Amico and Gioacchino Cafiero and Gaetano Iuso},
year = {2021},
date = {2021-01-01},
booktitle = {XXIX A.I.VE.LA. National Meeting},
publisher = {Online},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Gehlert, Pascal; Cherfane, Ziad; Cafiero, Gioacchino; Vassilicos, John Christos
Effect of Multiscale Endplates on Wing-Tip Vortex Journal Article
In: AIAA JOURNAL, pp. 1–15, 2021.
@article{ 11583_2873817,
title = {Effect of Multiscale Endplates on Wing-Tip Vortex},
author = {Pascal Gehlert and Ziad Cherfane and Gioacchino Cafiero and John Christos Vassilicos},
doi = {10.2514/1.J059878},
year = {2021},
date = {2021-01-01},
journal = {AIAA JOURNAL},
pages = {1--15},
publisher = {American Institute of Aeronautics and Astronautics (AIAA)},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Amico, Enrico; Bari, Domenico Di; Cafiero, Gioacchino; Iuso, Gaetano
Genetic Algorithm based control of the wake of a bluff body Conference
XXIX A.I.VE.LA. National Meeting, Online, 2021.
@conference{ 11583_2957504,
title = {Genetic Algorithm based control of the wake of a bluff body},
author = {Enrico Amico and Domenico Di Bari and Gioacchino Cafiero and Gaetano Iuso},
year = {2021},
date = {2021-01-01},
booktitle = {XXIX A.I.VE.LA. National Meeting},
publisher = {Online},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
2020
CERUTTI, JUAN JOSE; SARDU, COSTANTINO; CAFIERO, GIOACCHINO; IUSO, Gaetano
Active Flow Control on a Square-Back Road Vehicle Journal Article
In: FLUIDS, 2020.
@article{ 11583_2813820,
title = {Active Flow Control on a Square-Back Road Vehicle},
author = {JUAN JOSE CERUTTI and COSTANTINO SARDU and GIOACCHINO CAFIERO and Gaetano IUSO},
year = {2020},
date = {2020-01-01},
journal = {FLUIDS},
publisher = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gregorio, F. De; Visingardi, A.; Coletta, M.; Iuso, G.
An assessment of vortex detection criteria for 2C-2D PIV data Book Chapter
In: Journal of Physics: Conference Series, vol. 1589, pp. 1–17, Institute of Physics (IOP), 2020.
@inbook{ 11583_2862124,
title = {An assessment of vortex detection criteria for 2C-2D PIV data},
author = {F. De Gregorio and A. Visingardi and M. Coletta and G. Iuso},
doi = {10.1088/1742-6596/1589/1/012001},
year = {2020},
date = {2020-01-01},
booktitle = {Journal of Physics: Conference Series},
volume = {1589},
pages = {1--17},
publisher = {Institute of Physics (IOP)},
abstract = {The aim of the article is to propose a robust and reliable engineering method for identifying and characterizing vortical structures within a flow field measured with a classic twocomponent PIV measurement system. Some of the most popular vortex-detection criteria are briefly presented for comparison purposes. Many of these fail if spurious vectors are present within the flow field due to poor PIV image quality. The proposed method was tested both on synthetic images of ideal vortices, having different spatial resolutions and different noise levels in order to perform a parametric assessment, and on real PIV images of a four-bladed rotor wake.},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
The aim of the article is to propose a robust and reliable engineering method for identifying and characterizing vortical structures within a flow field measured with a classic twocomponent PIV measurement system. Some of the most popular vortex-detection criteria are briefly presented for comparison purposes. Many of these fail if spurious vectors are present within the flow field due to poor PIV image quality. The proposed method was tested both on synthetic images of ideal vortices, having different spatial resolutions and different noise levels in order to perform a parametric assessment, and on real PIV images of a four-bladed rotor wake.
D’Ambrosio, Domenic; Marsilio, Roberto; Cafiero, Gioacchino; Iuso, Gaetano; Uggenti, Anna Chiara; Gerboni, Raffaella
Design of a large wind tunnel for risk assessment on-board Oil & Gas Platforms Conference
10th EASN Virtual International Conference, EASN, 2020.
@conference{ 11583_2957500,
title = {Design of a large wind tunnel for risk assessment on-board Oil & Gas Platforms},
author = {Domenic D'Ambrosio and Roberto Marsilio and Gioacchino Cafiero and Gaetano Iuso and Anna Chiara Uggenti and Raffaella Gerboni},
year = {2020},
date = {2020-01-01},
booktitle = {10th EASN Virtual International Conference},
publisher = {EASN},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Serpieri, J.; Ianiro, A.
Gasprop: Reducing blade compressibility effects through waste-heat recovery in aircraft engines Journal Article
In: AIAA JOURNAL, vol. 58, no. 2, pp. 987–990, 2020.
@article{ 11583_2965996,
title = {Gasprop: Reducing blade compressibility effects through waste-heat recovery in aircraft engines},
author = {J. Serpieri and A. Ianiro},
doi = {10.2514/1.J058616},
year = {2020},
date = {2020-01-01},
journal = {AIAA JOURNAL},
volume = {58},
number = {2},
pages = {987--990},
publisher = {American Institute of Aeronautics and Astronautics Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2019
Cerutti, J. J.; Cafiero, G.; Iuso, G.
Aerodynamics of two square back vehicles in platooning configuration Conference
Proceedings 15th International Conference on Fluid Control, Measurements and Visualization, International Conference on Fluid Control, Measurements and Visualization, 2019.
@conference{ 11583_2736114,
title = {Aerodynamics of two square back vehicles in platooning configuration},
author = {J. J. Cerutti and G. Cafiero and G. Iuso},
year = {2019},
date = {2019-01-01},
booktitle = {Proceedings 15th International Conference on Fluid Control, Measurements and Visualization},
publisher = {International Conference on Fluid Control, Measurements and Visualization},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Iuso, G.; Virone, G.; Cafiero, G.; Bonisoli, E.; Lisitano, D.; Venturini, S.
Aeroelastic-structural coupling in antenna prototype for windy open-space Conference
Proceedings VIII International Conference on Computational Methods for Coupled Problems in Science and Engineering, Proceedings VIII International Conference on Computational Methods for Coupled Problems in Science and Engineering, 2019.
@conference{ 11583_2736092,
title = {Aeroelastic-structural coupling in antenna prototype for windy open-space},
author = {G. Iuso and G. Virone and G. Cafiero and E. Bonisoli and D. Lisitano and S. Venturini},
year = {2019},
date = {2019-01-01},
booktitle = {Proceedings VIII International Conference on Computational Methods for Coupled Problems in Science and Engineering},
publisher = {Proceedings VIII International Conference on Computational Methods for Coupled Problems in Science and Engineering},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
CICCA, GAETANO MARIA DI; Iuso, Gaetano; Onorato, Michele
Characteristics of the flow around a superhydrophobic obstacle Conference
Proceedings of the 15th International Conference on Fluid Control, Measurements and Visualization, 27-30 May 2019, Naples, Italy, Prof. Gennaro Cardone – Università di Napoli Federico II, Napoli, 2019.
@conference{ 11583_2736677,
title = {Characteristics of the flow around a superhydrophobic obstacle},
author = {GAETANO MARIA DI CICCA and Gaetano Iuso and Michele Onorato},
year = {2019},
date = {2019-01-01},
booktitle = {Proceedings of the 15th International Conference on Fluid Control, Measurements and Visualization, 27-30 May 2019, Naples, Italy},
publisher = {Prof. Gennaro Cardone - Università di Napoli Federico II},
address = {Napoli},
abstract = {The flow around a partially buried circular cylinder on a smooth plane boundary is studied using Particle Image Velocimetry. The cylinder axis is perpendicular to the incoming flow. The burial ratio B/D is equal to 0.5 , where B is the burial depth and D is the diameter of the cylinder. The ratio between the span of the obstacle and its diameter is equal to 11.7 . The flow is considered nominally two-dimensional. The case in which the obstacle is coated with a random-textured superhydrophobic surface is compared with the case of a smooth surface. In the superhydrophobic case the surface was prepared by using a double layer spray coating method (NeverWet solution). An extreme contact angle of about 165° was evaluated. Measurements were carried out in a closed-loop water tunnel for a Reynolds number, based on the cylinder diameter and on the incoming flow velocity Ue , of about 360. The incoming boundary layer is laminar and the boundary layer thickness, in absence of the obstacle, is of the same order of the obstacle height. The present research is related to the understanding of the role of slip conditions in presence of pressure gradients in order to provide useful information for flow control strategy.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The flow around a partially buried circular cylinder on a smooth plane boundary is studied using Particle Image Velocimetry. The cylinder axis is perpendicular to the incoming flow. The burial ratio B/D is equal to 0.5 , where B is the burial depth and D is the diameter of the cylinder. The ratio between the span of the obstacle and its diameter is equal to 11.7 . The flow is considered nominally two-dimensional. The case in which the obstacle is coated with a random-textured superhydrophobic surface is compared with the case of a smooth surface. In the superhydrophobic case the surface was prepared by using a double layer spray coating method (NeverWet solution). An extreme contact angle of about 165° was evaluated. Measurements were carried out in a closed-loop water tunnel for a Reynolds number, based on the cylinder diameter and on the incoming flow velocity Ue , of about 360. The incoming boundary layer is laminar and the boundary layer thickness, in absence of the obstacle, is of the same order of the obstacle height. The present research is related to the understanding of the role of slip conditions in presence of pressure gradients in order to provide useful information for flow control strategy.
Cerutti, J. J.; Cafiero, G.; Iuso, G.
Drag reduction of a road vehicle using continuous jets Conference
Titolo volume non avvalorato, European Drag Reduction Flow Control Meeting, 2019.
@conference{ 11583_2736113,
title = {Drag reduction of a road vehicle using continuous jets},
author = {J. J. Cerutti and G. Cafiero and G. Iuso},
year = {2019},
date = {2019-01-01},
booktitle = {Titolo volume non avvalorato},
publisher = {European Drag Reduction Flow Control Meeting},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Iuso, G.; Cafiero, G.
G. Iuso and G. Cafiero Finalization of the plate coupons and manufacturing Clean Sky 2 – Regional Innovative Aircraft Development Platform. REG-2.1.6-TN-POLITO-TECH-219169-A Miscellaneous
2019.
@misc{ 11583_2737232,
title = {G. Iuso and G. Cafiero
Finalization of the plate coupons and manufacturing
Clean Sky 2 - Regional Innovative Aircraft Development Platform. REG-2.1.6-TN-POLITO-TECH-219169-A},
author = {G. Iuso and G. Cafiero},
year = {2019},
date = {2019-01-01},
pages = {1--21},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Discetti, S.; Bellani, G.; Orlu, R.; Serpieri, J.; Vila, C. Sanmiguel; Raiola, M.; Zheng, X.; Mascotelli, L.; Talamelli, A.; Ianiro, A.
Characterization of very-large-scale motions in high-Re pipe flows Journal Article
In: EXPERIMENTAL THERMAL AND FLUID SCIENCE, vol. 104, pp. 1–8, 2019.
@article{ 11583_2965998,
title = {Characterization of very-large-scale motions in high-Re pipe flows},
author = {S. Discetti and G. Bellani and R. Orlu and J. Serpieri and C. Sanmiguel Vila and M. Raiola and X. Zheng and L. Mascotelli and A. Talamelli and A. Ianiro},
doi = {10.1016/j.expthermflusci.2019.02.001},
year = {2019},
date = {2019-01-01},
journal = {EXPERIMENTAL THERMAL AND FLUID SCIENCE},
volume = {104},
pages = {1--8},
publisher = {Elsevier Inc.},
abstract = {Very-large-scale structures in pipe flows are characterized using an extended Proper Orthogonal Decomposition (POD)-based estimation. Synchronized non-time-resolved Particle Image Velocimetry (PIV) and time-resolved, multi-point hot-wire measurements are integrated for the estimation of turbulent structures in a pipe flow at friction Reynolds numbers of 9500 and 20000. This technique enhances the temporal resolution of PIV, thus providing a time-resolved description of the dynamics of the large-scale motions. The experiments are carried out in the CICLoPE facility. A novel criterion for the statistical characterization of the large-scale motions is introduced, based on the time-resolved dynamically-estimated POD time coefficients. It is shown that high-momentum events are less persistent than low-momentum events, and tend to occur closer to the wall. These differences are further enhanced with increasing Reynolds number.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Very-large-scale structures in pipe flows are characterized using an extended Proper Orthogonal Decomposition (POD)-based estimation. Synchronized non-time-resolved Particle Image Velocimetry (PIV) and time-resolved, multi-point hot-wire measurements are integrated for the estimation of turbulent structures in a pipe flow at friction Reynolds numbers of 9500 and 20000. This technique enhances the temporal resolution of PIV, thus providing a time-resolved description of the dynamics of the large-scale motions. The experiments are carried out in the CICLoPE facility. A novel criterion for the statistical characterization of the large-scale motions is introduced, based on the time-resolved dynamically-estimated POD time coefficients. It is shown that high-momentum events are less persistent than low-momentum events, and tend to occur closer to the wall. These differences are further enhanced with increasing Reynolds number.
2018
Cicca, G. M. Di; Iuso, G.; Onorato, M.
PIV study of the turbulent structure of a boundary layer developing over a rough surface Proceedings Article
In: Proceedings of the 12th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements, University of Montpellier, Montpellier – FRA, 2018, (Contributo in Atti di convegno).
@inproceedings{inproceedingsb,
title = {PIV study of the turbulent structure of a boundary layer developing over a rough surface},
author = {G. M. Di Cicca and G. Iuso and M. Onorato},
year = {2018},
date = {2018-09-01},
booktitle = {Proceedings of the 12th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements},
publisher = {University of Montpellier},
address = {Montpellier - FRA},
abstract = {PIV measurements at relatively low Reynolds number in a turbulent boundary layer over a three-dimensional roughened surface, consisting of py-ramidal rows, are presented. Measurements were taken in a streamwise wall normal plane intercepting the apex of a row of pyramids and the diagonal of the square base. The results shown in the present paper point out the non-homogeneity of the flow in the roughness sub-layer. The different flow behaviours along the ascendant and the descendent part of the pyramids and in the region between two consecutive pyramids were investigated. Low values of the streamwise component of the mean velocity and high values of the Reynolds shear stresses are present in the down-stream part of the pyramids, near their base. In order to understand the origin of the high tur-bulence activity observed downstream the pyramids, near their base, a conditional analysis based on the quadrant method was performed. Particularly, the flow events producing the high values of the Reynolds shear stress were analyzed. Two-point streamwise velocity autocorrelation functions show a loss of longitudinal coherence due to the action of the surface roughness.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
PIV measurements at relatively low Reynolds number in a turbulent boundary layer over a three-dimensional roughened surface, consisting of py-ramidal rows, are presented. Measurements were taken in a streamwise wall normal plane intercepting the apex of a row of pyramids and the diagonal of the square base. The results shown in the present paper point out the non-homogeneity of the flow in the roughness sub-layer. The different flow behaviours along the ascendant and the descendent part of the pyramids and in the region between two consecutive pyramids were investigated. Low values of the streamwise component of the mean velocity and high values of the Reynolds shear stresses are present in the down-stream part of the pyramids, near their base. In order to understand the origin of the high tur-bulence activity observed downstream the pyramids, near their base, a conditional analysis based on the quadrant method was performed. Particularly, the flow events producing the high values of the Reynolds shear stress were analyzed. Two-point streamwise velocity autocorrelation functions show a loss of longitudinal coherence due to the action of the surface roughness.
Cerutti, J. J.; Sardu, C.; Iuso, G.
Drag reduction of squared-back body using continuous jets differently positioned on the rear base Proceedings Article
In: Titolo volume non avvalorato, International Conference on Experimental Fluid Mechanics, 2018, (Contributo in Atti di convegno).
@inproceedings{inproceedings,
title = {Drag reduction of squared-back body using continuous jets differently positioned on the rear base},
author = {J. J. Cerutti and C. Sardu and G. Iuso},
year = {2018},
date = {2018-07-01},
booktitle = {Titolo volume non avvalorato},
publisher = {International Conference on Experimental Fluid Mechanics},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gehlert, P.; Cafiero, G.; Vassilicos, J. C.
Effect of fractal endplates on the wingtip vortex Conference
AIAA Aerospace Sciences Meeting, 2018, American Institute of Aeronautics and Astronautics Inc, AIAA, 2018, ISBN: 9781624105241.
@conference{ 11583_2728392,
title = {Effect of fractal endplates on the wingtip vortex},
author = {P. Gehlert and G. Cafiero and J. C. Vassilicos},
url = {https://arc.aiaa.org/doi/10.2514/6.2018-1796},
doi = {10.2514/6.2018-1796},
isbn = {9781624105241},
year = {2018},
date = {2018-01-01},
booktitle = {AIAA Aerospace Sciences Meeting, 2018},
publisher = {American Institute of Aeronautics and Astronautics Inc, AIAA},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Groot, K. J.; Serpieri, J.; Pinna, F.; Kotsonis, M.
Secondary crossflow instability through global analysis of measured base flows Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 846, pp. 605–653, 2018.
@article{ 11583_2966006,
title = {Secondary crossflow instability through global analysis of measured base flows},
author = {K. J. Groot and J. Serpieri and F. Pinna and M. Kotsonis},
doi = {10.1017/jfm.2018.253},
year = {2018},
date = {2018-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {846},
pages = {605--653},
publisher = {Cambridge University Press},
abstract = {A combined experimental and numerical approach to the analysis of the secondary stability of realistic swept-wing boundary layers is presented. Global linear stability theory is applied to experimentally measured base flows. These base flows are three-dimensional laminar boundary layers subject to spanwise distortion due to the presence of primary stationary crossflow vortices. A full three-dimensional description of these flows is accessed through the use of tomographic particle image velocimetry (PIV). The stability analysis solves for the secondary high-frequency modes of type I and type II, ultimately responsible for turbulent breakdown. Several pertinent parameters arising from the application of the proposed methodology are investigated, including the mean flow ensemble size and the measurement domain extent. Extensive use is made of the decomposition of the eigensolutions into the terms of the Reynolds-Orr equation, allowing insight into the production and/or destruction of perturbations from various base flow features. Stability results demonstrate satisfactory convergence with respect to the mean flow ensemble size and are independent of the handling of the exterior of the measurement domain. The Reynolds-Orr analysis reveals a close relationship between the type I and type II instability modes with spanwise and wall-normal gradients of the base flow, respectively. The structural role of the in-plane velocity components in the perturbation growth, topology and sensitivity is identified. Using the developed framework, further insight is gained into the linear growth mechanisms and later stages of transition via the primary and secondary crossflow instabilities. Furthermore, the proposed methodology enables the extension and enhancement of the experimental measurement data to the pertinent instability eigenmodes. The present work is the first demonstration of the use of a measured base flow for stability analysis applied to the swept-wing boundary layer, directly avoiding the modelling of the primary vortices receptivity processes.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A combined experimental and numerical approach to the analysis of the secondary stability of realistic swept-wing boundary layers is presented. Global linear stability theory is applied to experimentally measured base flows. These base flows are three-dimensional laminar boundary layers subject to spanwise distortion due to the presence of primary stationary crossflow vortices. A full three-dimensional description of these flows is accessed through the use of tomographic particle image velocimetry (PIV). The stability analysis solves for the secondary high-frequency modes of type I and type II, ultimately responsible for turbulent breakdown. Several pertinent parameters arising from the application of the proposed methodology are investigated, including the mean flow ensemble size and the measurement domain extent. Extensive use is made of the decomposition of the eigensolutions into the terms of the Reynolds-Orr equation, allowing insight into the production and/or destruction of perturbations from various base flow features. Stability results demonstrate satisfactory convergence with respect to the mean flow ensemble size and are independent of the handling of the exterior of the measurement domain. The Reynolds-Orr analysis reveals a close relationship between the type I and type II instability modes with spanwise and wall-normal gradients of the base flow, respectively. The structural role of the in-plane velocity components in the perturbation growth, topology and sensitivity is identified. Using the developed framework, further insight is gained into the linear growth mechanisms and later stages of transition via the primary and secondary crossflow instabilities. Furthermore, the proposed methodology enables the extension and enhancement of the experimental measurement data to the pertinent instability eigenmodes. The present work is the first demonstration of the use of a measured base flow for stability analysis applied to the swept-wing boundary layer, directly avoiding the modelling of the primary vortices receptivity processes.
Serpieri, J.; Kotsonis, M.
Conditioning of unsteady cross-flow instability modes using dielectric barrier discharge plasma actuators Journal Article
In: EXPERIMENTAL THERMAL AND FLUID SCIENCE, vol. 93, pp. 305–318, 2018.
@article{ 11583_2965994,
title = {Conditioning of unsteady cross-flow instability modes using dielectric barrier discharge plasma actuators},
author = {J. Serpieri and M. Kotsonis},
doi = {10.1016/j.expthermflusci.2018.01.007},
year = {2018},
date = {2018-01-01},
journal = {EXPERIMENTAL THERMAL AND FLUID SCIENCE},
volume = {93},
pages = {305--318},
publisher = {Elsevier Inc.},
abstract = {In this study, experiments are performed towards the identification and measurement of unsteady modes occurring in a transitional swept wing boundary layer. These modes are generated by the interaction between the primary stationary and travelling cross-flow instabilities or by secondary instability mechanisms of the stationary cross-flow vortices and have a crucial role in the laminar-to-turbulent breakdown process. Detailed hot-wire measurements were performed at the location of stationary instability amplitude-saturation. In order to deterministically capture the spatio-temporal evolution of the unsteady modes, measurements were phase- and frequency-conditioned using concurrent forcing by means of a dielectric barrier discharge plasma actuator mounted upstream of the measurement domain. The actuator effect, when positioned sufficiently upstream the secondary modes onset, was tuned such to successfully condition the high-frequency type-I and the low-frequency type-III modes without modifying the transition evolution. Two primary stationary cross-flow vortices of different amplitude were measured, revealing the effect of base-flow variations on the growth of travelling instabilities. The response of these two stationary waves to the naturally occurring and forced fluctuations was captured at different chordwise positions. Additionally, the deterministic conditioning of the instability phase to the phase of the actuation allowed phase-averaged reconstruction of the spatio-temporal evolution of the unsteady structures providing valuable insight on their topology. Finally, the effect of locating the actuator at a more downstream position, closer to the type-I mode branch-I, resulted in laminar-to turbulent breakdown for the high-frequency actuation while the low-frequency forcing showed milder effects on the transition evolution.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this study, experiments are performed towards the identification and measurement of unsteady modes occurring in a transitional swept wing boundary layer. These modes are generated by the interaction between the primary stationary and travelling cross-flow instabilities or by secondary instability mechanisms of the stationary cross-flow vortices and have a crucial role in the laminar-to-turbulent breakdown process. Detailed hot-wire measurements were performed at the location of stationary instability amplitude-saturation. In order to deterministically capture the spatio-temporal evolution of the unsteady modes, measurements were phase- and frequency-conditioned using concurrent forcing by means of a dielectric barrier discharge plasma actuator mounted upstream of the measurement domain. The actuator effect, when positioned sufficiently upstream the secondary modes onset, was tuned such to successfully condition the high-frequency type-I and the low-frequency type-III modes without modifying the transition evolution. Two primary stationary cross-flow vortices of different amplitude were measured, revealing the effect of base-flow variations on the growth of travelling instabilities. The response of these two stationary waves to the naturally occurring and forced fluctuations was captured at different chordwise positions. Additionally, the deterministic conditioning of the instability phase to the phase of the actuation allowed phase-averaged reconstruction of the spatio-temporal evolution of the unsteady structures providing valuable insight on their topology. Finally, the effect of locating the actuator at a more downstream position, closer to the type-I mode branch-I, resulted in laminar-to turbulent breakdown for the high-frequency actuation while the low-frequency forcing showed milder effects on the transition evolution.
Yadala, S.; Hehner, M. T.; Serpieri, J.; Benard, N.; Dorr, P. C.; Kloker, M. J.; Kotsonis, M.
Experimental control of swept-wing transition through base-flow modification by plasma actuators Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 844, 2018.
@article{ 11583_2965990,
title = {Experimental control of swept-wing transition through base-flow modification by plasma actuators},
author = {S. Yadala and M. T. Hehner and J. Serpieri and N. Benard and P. C. Dorr and M. J. Kloker and M. Kotsonis},
doi = {10.1017/jfm.2018.268},
year = {2018},
date = {2018-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {844},
publisher = {Cambridge University Press},
abstract = {Control of laminar-to-turbulent transition on a swept-wing is achieved by base-flow modification in an experimental framework, up to a chord Reynolds number of 2.5 million. This technique is based on the control strategy used in the numerical simulation by Dörr & Kloker (J. Phys. D: Appl. Phys., vol. 48, 2015b, 285205). A spanwise uniform body force is introduced using dielectric barrier discharge plasma actuators, to either force against or along the local cross-flow component of the boundary layer. The effect of forcing on the stability of the boundary layer is analysed using a simplified model proposed by Serpieri et al. (J. Fluid Mech., vol. 833, 2017, pp. 164-205). A minimal thickness plasma actuator is fabricated using spray-on techniques and positioned near the leading edge of the swept-wing, while infrared thermography is used to detect and quantify transition location. Results from both the simplified model and experiment indicate that forcing along the local cross-flow component promotes transition while forcing against successfully delays transition. This is the first experimental demonstration of swept-wing transition delay via base-flow modification using plasma actuators.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Control of laminar-to-turbulent transition on a swept-wing is achieved by base-flow modification in an experimental framework, up to a chord Reynolds number of 2.5 million. This technique is based on the control strategy used in the numerical simulation by Dörr & Kloker (J. Phys. D: Appl. Phys., vol. 48, 2015b, 285205). A spanwise uniform body force is introduced using dielectric barrier discharge plasma actuators, to either force against or along the local cross-flow component of the boundary layer. The effect of forcing on the stability of the boundary layer is analysed using a simplified model proposed by Serpieri et al. (J. Fluid Mech., vol. 833, 2017, pp. 164-205). A minimal thickness plasma actuator is fabricated using spray-on techniques and positioned near the leading edge of the swept-wing, while infrared thermography is used to detect and quantify transition location. Results from both the simplified model and experiment indicate that forcing along the local cross-flow component promotes transition while forcing against successfully delays transition. This is the first experimental demonstration of swept-wing transition delay via base-flow modification using plasma actuators.
2017
C., Sardu; JOSE, CERUTTI JUAN; G., Iuso
Wind tunnel investigation on a squared–back commercial vehicle Proceedings Article
In: Proceedings of the XXIII Conference of the Italian Association of Theoretical and Applied Mechanics, pp. 175-190, GECHI EDIZIONI, Mediglia (MI) – ITA, 2017, ISBN: 978-889-42484-7-0, (Contributo in Atti di convegno).
@inproceedings{inproceedingsc,
title = {Wind tunnel investigation on a squared–back commercial vehicle},
author = {Sardu C. and CERUTTI JUAN JOSE and Iuso G.},
url = {http://www.aimeta2017.unisa.it/node/52},
isbn = {978-889-42484-7-0},
year = {2017},
date = {2017-09-01},
booktitle = {Proceedings of the XXIII Conference of the Italian Association of Theoretical and Applied Mechanics},
volume = {1},
pages = {175-190},
publisher = {GECHI EDIZIONI},
address = {Mediglia (MI) - ITA},
abstract = {The assessment of an appropriate methodology for a wind tunnel investigation on a square back vehicle model is presented and discussed. The CD−Re curve is evaluated in order to identify the adequate range of Reynolds number for the tests. The drag coefficient value is attested at CD = 0.465 which is in accordance with the literature results for the same category of
vehicles considered. The repeatability and the accuracy of the CD have been analyzed through a campaign of measurements and an error propagation analysis is dedicated to associate the
correct uncertainty to the drag coefficient values. The analysis of statistical convergence of the measured quantities is also carried out in order to fix the adequate acquisition time. The
results of the experimental investigation regarding the measurement methodology, drag coefficient, base pressure distribution, position of the center of pressure, and wake measurements
are presented highlighting the main natural flow features. Moreover, the pressure fluctuations measured by microphone sensors allowed to evidence the unsteadiness and possible flow configurations involving the entire rear part.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The assessment of an appropriate methodology for a wind tunnel investigation on a square back vehicle model is presented and discussed. The CD−Re curve is evaluated in order to identify the adequate range of Reynolds number for the tests. The drag coefficient value is attested at CD = 0.465 which is in accordance with the literature results for the same category of
vehicles considered. The repeatability and the accuracy of the CD have been analyzed through a campaign of measurements and an error propagation analysis is dedicated to associate the
correct uncertainty to the drag coefficient values. The analysis of statistical convergence of the measured quantities is also carried out in order to fix the adequate acquisition time. The
results of the experimental investigation regarding the measurement methodology, drag coefficient, base pressure distribution, position of the center of pressure, and wake measurements
are presented highlighting the main natural flow features. Moreover, the pressure fluctuations measured by microphone sensors allowed to evidence the unsteadiness and possible flow configurations involving the entire rear part.
vehicles considered. The repeatability and the accuracy of the CD have been analyzed through a campaign of measurements and an error propagation analysis is dedicated to associate the
correct uncertainty to the drag coefficient values. The analysis of statistical convergence of the measured quantities is also carried out in order to fix the adequate acquisition time. The
results of the experimental investigation regarding the measurement methodology, drag coefficient, base pressure distribution, position of the center of pressure, and wake measurements
are presented highlighting the main natural flow features. Moreover, the pressure fluctuations measured by microphone sensors allowed to evidence the unsteadiness and possible flow configurations involving the entire rear part.
F., Spertino; A., Ciocia; P., Di Leo; G., Iuso; G., Malgaroli; L., Roberto
Experimental testing of a horizontal-axis wind turbine to assess its performance Proceedings Article
In: Proc. of 2nd IMEKO TC4 International Symposium and 20th International Workshop on ADC Modelling and Testing 2017: Supporting World Development Through Electrical and Electronic Measurements, pp. 411-414, IMEKO-International Measurement Federation Secretariat, 2017, ISBN: 978-151084976-1, (Contributo in Atti di convegno).
@inproceedings{inproceedingse,
title = {Experimental testing of a horizontal-axis wind turbine to assess its performance},
author = {Spertino F. and Ciocia A. and Di Leo P. and Iuso G. and Malgaroli G. and Roberto L.},
isbn = {978-151084976-1},
year = {2017},
date = {2017-09-01},
booktitle = {Proc. of 2nd IMEKO TC4 International Symposium and 20th International Workshop on ADC Modelling and Testing 2017: Supporting World Development Through Electrical and Electronic Measurements},
volume = {Volume 2017-September},
pages = {411-414},
publisher = {IMEKO-International Measurement Federation Secretariat},
abstract = {This paper describes a test procedure to investigate the performance of a micro wind turbine with horizontal-axis. A 3D model of a rotor with five blades has been designed by a MATLAB software; its airfoil is optimized to efficiently work at low wind speed. The rotor is coupled to an electric generator and this equipment is tested in a wind tunnel. An anemometer is used to measure and set the desired wind speeds. Electric quantities, i.e., voltage, current and power, are acquired by a digital multimeter. A variable resistance is used to change the operating point of the generator. Preliminary results are reported that refer to the application of the proposed test procedures to a wind turbine with a 0.2 m2 swept area.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper describes a test procedure to investigate the performance of a micro wind turbine with horizontal-axis. A 3D model of a rotor with five blades has been designed by a MATLAB software; its airfoil is optimized to efficiently work at low wind speed. The rotor is coupled to an electric generator and this equipment is tested in a wind tunnel. An anemometer is used to measure and set the desired wind speeds. Electric quantities, i.e., voltage, current and power, are acquired by a digital multimeter. A variable resistance is used to change the operating point of the generator. Preliminary results are reported that refer to the application of the proposed test procedures to a wind turbine with a 0.2 m2 swept area.
Cafiero, Gioacchino; Castrillo, Giusy; Greco, Carlo Salvatore; Astarita, Tommaso
Effect of the grid geometry on the convective heat transfer of impinging jets Journal Article
In: INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, vol. 104, pp. 39–50, 2017.
@article{ 11583_2728389,
title = {Effect of the grid geometry on the convective heat transfer of impinging jets},
author = {Gioacchino Cafiero and Giusy Castrillo and Carlo Salvatore Greco and Tommaso Astarita},
url = {http://www.journals.elsevier.com/international-journal-of-heat-and-mass-transfer/},
doi = {10.1016/j.ijheatmasstransfer.2016.08.003},
year = {2017},
date = {2017-01-01},
journal = {INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER},
volume = {104},
pages = {39--50},
publisher = {Elsevier Ltd},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ceglia, Giuseppe; Cafiero, Gioacchino; Astarita, Tommaso
Experimental investigation on the three-dimensional organization of the flow structures in precessing jets by tomographic PIV Journal Article
In: EXPERIMENTAL THERMAL AND FLUID SCIENCE, vol. 89, pp. 166–180, 2017.
@article{ 11583_2728390,
title = {Experimental investigation on the three-dimensional organization of the flow structures in precessing jets by tomographic PIV},
author = {Giuseppe Ceglia and Gioacchino Cafiero and Tommaso Astarita},
doi = {10.1016/j.expthermflusci.2017.08.008},
year = {2017},
date = {2017-01-01},
journal = {EXPERIMENTAL THERMAL AND FLUID SCIENCE},
volume = {89},
pages = {166--180},
publisher = {Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Serpieri, J.; Venkata, S. Yadala; Kotsonis, M.
Conditioning of cross-flow instability modes using dielectric barrier discharge plasma actuators Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 833, pp. 164–205, 2017.
@article{ 11583_2966004,
title = {Conditioning of cross-flow instability modes using dielectric barrier discharge plasma actuators},
author = {J. Serpieri and S. Yadala Venkata and M. Kotsonis},
doi = {10.1017/jfm.2017.707},
year = {2017},
date = {2017-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {833},
pages = {164--205},
publisher = {Cambridge University Press},
abstract = {In the current study, selective forcing of cross-flow instability modes evolving on a swept wing at is achieved by means of spanwise-modulated plasma actuators, positioned near the leading edge. In the perspective of laminar flow control, the followed methodology holds on the discrete roughness elements/upstream flow deformation (DRE/UFD) approach, thoroughly investigated by e.g. Saric et al. (AIAA Paper 1998-781, 1998), Malik et al. (J. Fluid Mech., vol. 399, 1999, pp. 85-115) and Wassermann & Kloker (J. Fluid Mech., vol. 456, 2002, pp. 49-84). The possibility of using active devices for UFD provides several advantages over passive means, allowing for a wider range of operating numbers and pressure distributions. In the present work, customised alternating current dielectric barrier discharge plasma actuators have been designed, manufactured and characterised. The authority of the actuators in forcing monochromatic stationary cross-flow modes at different spanwise wavelengths is assessed by means of infrared thermography. Moreover, quantitative spatio-temporal measurements of the boundary layer velocity field are performed using time-resolved particle image velocimetry. The results reveal distinct steady and unsteady forcing contributions of the plasma actuator on the boundary layer. It is shown that the actuators introduce unsteady fluctuations in the boundary layer, amplifying at frequencies significantly lower than the actuation frequency. In line with the DRE/UFD strategy, forcing a sub-critical stationary mode, with a shorter wavelength compared to the naturally selected mode, results in less amplified primary vortices and related fluctuations, compared to the critical forcing case. The effect of the forcing on the flow stability is further inspected by combining the measured actuators body force with the numerical solution of the laminar boundary layer and linear stability theory. The simplified methodology yields fast and computationally cheap estimates on the effect of steady forcing (magnitude and direction) on the boundary layer stability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the current study, selective forcing of cross-flow instability modes evolving on a swept wing at is achieved by means of spanwise-modulated plasma actuators, positioned near the leading edge. In the perspective of laminar flow control, the followed methodology holds on the discrete roughness elements/upstream flow deformation (DRE/UFD) approach, thoroughly investigated by e.g. Saric et al. (AIAA Paper 1998-781, 1998), Malik et al. (J. Fluid Mech., vol. 399, 1999, pp. 85-115) and Wassermann & Kloker (J. Fluid Mech., vol. 456, 2002, pp. 49-84). The possibility of using active devices for UFD provides several advantages over passive means, allowing for a wider range of operating numbers and pressure distributions. In the present work, customised alternating current dielectric barrier discharge plasma actuators have been designed, manufactured and characterised. The authority of the actuators in forcing monochromatic stationary cross-flow modes at different spanwise wavelengths is assessed by means of infrared thermography. Moreover, quantitative spatio-temporal measurements of the boundary layer velocity field are performed using time-resolved particle image velocimetry. The results reveal distinct steady and unsteady forcing contributions of the plasma actuator on the boundary layer. It is shown that the actuators introduce unsteady fluctuations in the boundary layer, amplifying at frequencies significantly lower than the actuation frequency. In line with the DRE/UFD strategy, forcing a sub-critical stationary mode, with a shorter wavelength compared to the naturally selected mode, results in less amplified primary vortices and related fluctuations, compared to the critical forcing case. The effect of the forcing on the flow stability is further inspected by combining the measured actuators body force with the numerical solution of the laminar boundary layer and linear stability theory. The simplified methodology yields fast and computationally cheap estimates on the effect of steady forcing (magnitude and direction) on the boundary layer stability.
Sedda, Salvatore; Sardu, Costantino; Iuso, Gaetano
Investigation of a novel VTOL aircraft concept for operations in urban areas Journal Article
In: AEROTECNICA MISSILI E SPAZIO, 2017, ISSN: 0365-7442, (Articolo in rivista).
@article{article,
title = {Investigation of a novel VTOL aircraft concept for operations in urban areas},
author = {Salvatore Sedda and Costantino Sardu and Gaetano Iuso},
issn = {0365-7442},
year = {2017},
date = {2017-01-01},
journal = {AEROTECNICA MISSILI E SPAZIO},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
MARCO, PETROLO; Erasmo, CARRERA; Gaetano, IUSO; Zdeněk, Pátek; Zdenek, Janda
Further results on the development of a novel VTOL aircraft, the Anuloid. Part I: Aerodynamics Journal Article
In: ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE, vol. 4, pp. 401-419, 2017, ISSN: 2287-528X, (Articolo in rivista).
@article{articleb,
title = {Further results on the development of a novel VTOL aircraft, the Anuloid. Part I: Aerodynamics},
author = {PETROLO MARCO and CARRERA Erasmo and IUSO Gaetano and Pátek Zdeněk and Janda Zdenek},
doi = {10.12989/aas.2017.4.4.401},
issn = {2287-528X},
year = {2017},
date = {2017-01-01},
journal = {ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE},
volume = {4},
pages = {401-419},
abstract = {This paper presents the main outcomes of the preliminary development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid has three main features: lift is provided by a ducted fan powered by a turboshaft; control capabilities and anti-torque are due to a system of fixed and movable surfaces that are placed in the circular internal duct and the bottom portion of the aircraft; the Coanda effect is exploited to enable the control capabilities of such surfaces. In this paper, results from CFD analyses and wind tunnel tests are presented. Horizontal and vertical flights were considered, including accelerated flight. Particular attention was paid to the experimental analysis of the Coanda effect via a reduced scale 3D printed model. The results suggest that the Coanda effect is continuously present at the lower surface of the Anuloid and may be exploited for the control of the aircraft. Also, very complex 3D flows may develop around the aircraft.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper presents the main outcomes of the preliminary development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid has three main features: lift is provided by a ducted fan powered by a turboshaft; control capabilities and anti-torque are due to a system of fixed and movable surfaces that are placed in the circular internal duct and the bottom portion of the aircraft; the Coanda effect is exploited to enable the control capabilities of such surfaces. In this paper, results from CFD analyses and wind tunnel tests are presented. Horizontal and vertical flights were considered, including accelerated flight. Particular attention was paid to the experimental analysis of the Coanda effect via a reduced scale 3D printed model. The results suggest that the Coanda effect is continuously present at the lower surface of the Anuloid and may be exploited for the control of the aircraft. Also, very complex 3D flows may develop around the aircraft.
2016
Castrillo, Giusy; Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso
Blob-enhanced reconstruction technique Journal Article
In: MEASUREMENT SCIENCE & TECHNOLOGY, vol. 27, 2016.
@article{ 11583_2728385,
title = {Blob-enhanced reconstruction technique},
author = {Giusy Castrillo and Gioacchino Cafiero and Stefano Discetti and Tommaso Astarita},
url = {http://iopscience.iop.org/article/10.1088/0957-0233/27/9/094011/pdf},
doi = {10.1088/0957-0233/27/9/094011},
year = {2016},
date = {2016-01-01},
journal = {MEASUREMENT SCIENCE & TECHNOLOGY},
volume = {27},
publisher = {Institute of Physics Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Agüera, Nereida; Cafiero, Gioacchino; Astarita, Tommaso; Discetti, Stefano
Ensemble 3D PTV for high resolution turbulent statistics Journal Article
In: MEASUREMENT SCIENCE & TECHNOLOGY, vol. 27, 2016.
@article{ 11583_2731898,
title = {Ensemble 3D PTV for high resolution turbulent statistics},
author = {Nereida Agüera and Gioacchino Cafiero and Tommaso Astarita and Stefano Discetti},
url = {http://iopscience.iop.org/article/10.1088/0957-0233/27/12/124011/pdf},
doi = {10.1088/0957-0233/27/12/124011},
year = {2016},
date = {2016-01-01},
journal = {MEASUREMENT SCIENCE & TECHNOLOGY},
volume = {27},
publisher = {Institute of Physics Publishing},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cafiero, Gioacchino; Woods, Andrew W.
Experiments on mixing in wakes in shallow water Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 804, pp. 351–369, 2016.
@article{ 11583_2728386,
title = {Experiments on mixing in wakes in shallow water},
author = {Gioacchino Cafiero and Andrew W. Woods},
url = {http://journals.cambridge.org/action/displayJournal?jid=FLM},
doi = {10.1017/jfm.2016.505},
year = {2016},
date = {2016-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {804},
pages = {351--369},
publisher = {Cambridge University Press},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cafiero, Gioacchino; Greco, Carlo Salvatore; Astarita, Tommaso; Discetti, Stefano
Flow field features of fractal impinging jets at short nozzle to plate distances Journal Article
In: EXPERIMENTAL THERMAL AND FLUID SCIENCE, vol. 78, pp. 334–344, 2016.
@article{ 11583_2728388,
title = {Flow field features of fractal impinging jets at short nozzle to plate distances},
author = {Gioacchino Cafiero and Carlo Salvatore Greco and Tommaso Astarita and Stefano Discetti},
doi = {10.1016/j.expthermflusci.2016.06.009},
year = {2016},
date = {2016-01-01},
journal = {EXPERIMENTAL THERMAL AND FLUID SCIENCE},
volume = {78},
pages = {334--344},
publisher = {Elsevier Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso
Flow field topology of impinging jets with fractal inserts Book Chapter
In: Springer Proceedings in Physics, vol. 165, pp. 243–248, Springer Science and Business Media, LLC, 2016, ISBN: 9783319291291.
@inbook{ 11583_2728384,
title = {Flow field topology of impinging jets with fractal inserts},
author = {Gioacchino Cafiero and Stefano Discetti and Tommaso Astarita},
url = {http://www.springer.com/series/361},
doi = {10.1007/978-3-319-29130-7_42},
isbn = {9783319291291},
year = {2016},
date = {2016-01-01},
booktitle = {Springer Proceedings in Physics},
volume = {165},
pages = {243--248},
publisher = {Springer Science and Business Media, LLC},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
Serpieri, J.; Kotsonis, M.
Three-dimensional organisation of primary and secondary crossflow instability Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 799, pp. 200–245, 2016.
@article{ 11583_2966002,
title = {Three-dimensional organisation of primary and secondary crossflow instability},
author = {J. Serpieri and M. Kotsonis},
doi = {10.1017/jfm.2016.379},
year = {2016},
date = {2016-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {799},
pages = {200--245},
publisher = {Cambridge University Press},
abstract = {An experimental investigation of primary and secondary crossflow instability developing in the boundary layer of a 45° swept wing at a chord Reynolds number of 2.17 × 106 is presented. Linear stability theory is applied for preliminary estimation of the flow stability while surface flow visualisation using fluorescent oil is employed to inspect the topological features of the transition region. Hot-wire anemometry is extensively used for the investigation of the developing boundary layer and identification of the statistical and spectral characteristics of the instability modes. Primary stationary, as well as unsteady type-I (z-mode), type-II (y-mode) and type-III modes are detected and quantified. Finally, three-component, three-dimensional measurements of the transitional boundary layer are performed using tomographic particle image velocimetry. This research presents the first application of an optical experimental technique for this type of flow. Among the optical techniques, tomographic velocimetry represents, to date, the most advanced approach allowing the investigation of spatially correlated flow structures in three-dimensional fields. Proper orthogonal decomposition (POD) analysis of the captured flow fields is applied to this goal. The first POD mode features a newly reported structure related to low-frequency oscillatory motion of the stationary vortices along the spanwise direction. The cause of this phenomenon is only conjectured. Its effect on transition is considered negligible but, given the related high energy level, it needs to be accounted for in experimental investigations. Secondary instability mechanisms are captured as well. The type-III mode corresponds to low-frequency primary travelling crossflow waves interacting with the stationary ones. It appears in the inner upwelling region of the stationary crossflow vortices and is characterised by elongated structures approximately aligned with the axis of the stationary waves. The type-I secondary instability consists instead of significantly inclined structures located at the outer upwelling region of the stationary vortices. The much narrower wavelength and higher advection velocity of these structures correlate with the higher-frequency content of this mode. The results of the investigation of both primary and secondary instability from the exploited techniques agree with and complement each other and are in line with existing literature. Finally, they present the first experimental observation of the secondary instability structures under natural flow conditions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental investigation of primary and secondary crossflow instability developing in the boundary layer of a 45° swept wing at a chord Reynolds number of 2.17 × 106 is presented. Linear stability theory is applied for preliminary estimation of the flow stability while surface flow visualisation using fluorescent oil is employed to inspect the topological features of the transition region. Hot-wire anemometry is extensively used for the investigation of the developing boundary layer and identification of the statistical and spectral characteristics of the instability modes. Primary stationary, as well as unsteady type-I (z-mode), type-II (y-mode) and type-III modes are detected and quantified. Finally, three-component, three-dimensional measurements of the transitional boundary layer are performed using tomographic particle image velocimetry. This research presents the first application of an optical experimental technique for this type of flow. Among the optical techniques, tomographic velocimetry represents, to date, the most advanced approach allowing the investigation of spatially correlated flow structures in three-dimensional fields. Proper orthogonal decomposition (POD) analysis of the captured flow fields is applied to this goal. The first POD mode features a newly reported structure related to low-frequency oscillatory motion of the stationary vortices along the spanwise direction. The cause of this phenomenon is only conjectured. Its effect on transition is considered negligible but, given the related high energy level, it needs to be accounted for in experimental investigations. Secondary instability mechanisms are captured as well. The type-III mode corresponds to low-frequency primary travelling crossflow waves interacting with the stationary ones. It appears in the inner upwelling region of the stationary crossflow vortices and is characterised by elongated structures approximately aligned with the axis of the stationary waves. The type-I secondary instability consists instead of significantly inclined structures located at the outer upwelling region of the stationary vortices. The much narrower wavelength and higher advection velocity of these structures correlate with the higher-frequency content of this mode. The results of the investigation of both primary and secondary instability from the exploited techniques agree with and complement each other and are in line with existing literature. Finally, they present the first experimental observation of the secondary instability structures under natural flow conditions.
COSTANTINO, SARDU; DAVIDE, LASAGNA; Gaetano, IUSO
Noise Filtering for Wall-Pressure Fluctuations in Measurements Around a Cylinder With Laminar and Turbulent Flow Separation Journal Article
In: JOURNAL OF FLUIDS ENGINEERING, vol. 138, pp. 061101, 2016, ISSN: 0098-2202, (Articolo in rivista).
@article{articlec,
title = {Noise Filtering for Wall-Pressure Fluctuations in Measurements Around a Cylinder With Laminar and Turbulent Flow Separation},
author = {SARDU COSTANTINO and LASAGNA DAVIDE and IUSO Gaetano},
doi = {10.1115/1.4032034},
issn = {0098-2202},
year = {2016},
date = {2016-01-01},
journal = {JOURNAL OF FLUIDS ENGINEERING},
volume = {138},
pages = {061101},
abstract = {This paper proposes two different noise cancelation techniques for cleaning wallpressure fluctuations signals. These fluctuations are measured around a circular cylinder
with laminar and turbulent flow separation. The noise cancelation techniques are based on Wiener and adaptive filters and use the signals of pressure transducers mounted in a
cross section of the cylinder and the signal of a free-field sensor opportunely located upstream. First, synthetic signals are used in order to validate the procedure. Then, both
techniques are applied to the experimental data. Specific attention is paid to the filter order, optimized by a method introduced in this paper. Both filter types showed a selective behavior preserving the essence of the fluid dynamic phenomena characterizing the flow fields at each Reynolds number tested, especially when laminar separation occurs.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper proposes two different noise cancelation techniques for cleaning wallpressure fluctuations signals. These fluctuations are measured around a circular cylinder
with laminar and turbulent flow separation. The noise cancelation techniques are based on Wiener and adaptive filters and use the signals of pressure transducers mounted in a
cross section of the cylinder and the signal of a free-field sensor opportunely located upstream. First, synthetic signals are used in order to validate the procedure. Then, both
techniques are applied to the experimental data. Specific attention is paid to the filter order, optimized by a method introduced in this paper. Both filter types showed a selective behavior preserving the essence of the fluid dynamic phenomena characterizing the flow fields at each Reynolds number tested, especially when laminar separation occurs.
with laminar and turbulent flow separation. The noise cancelation techniques are based on Wiener and adaptive filters and use the signals of pressure transducers mounted in a
cross section of the cylinder and the signal of a free-field sensor opportunely located upstream. First, synthetic signals are used in order to validate the procedure. Then, both
techniques are applied to the experimental data. Specific attention is paid to the filter order, optimized by a method introduced in this paper. Both filter types showed a selective behavior preserving the essence of the fluid dynamic phenomena characterizing the flow fields at each Reynolds number tested, especially when laminar separation occurs.
DAVIDE, LASAGNA; Gaetano, IUSO
Flow regimes in a trapped vortex cell Journal Article
In: EXPERIMENTS IN FLUIDS, vol. 57, pp. 1-20, 2016, ISSN: 0723-4864, (Articolo in rivista).
@article{articled,
title = {Flow regimes in a trapped vortex cell},
author = {LASAGNA DAVIDE and IUSO Gaetano},
doi = {10.1007/s00348-016-2125-9},
issn = {0723-4864},
year = {2016},
date = {2016-01-01},
journal = {EXPERIMENTS IN FLUIDS},
volume = {57},
pages = {1-20},
abstract = {This paper presents results of an experimental investigation on the flow in a trapped vortex cell embedded into a flat plate and interacting with a zero pressure-gradient boundary layer. The objective of the work is to describe the flow features and elucidate some of the governing physical mechanisms, in light of recent investigations on flow separation control using vortex cells. Hot-wire velocity measurements of the shear layer bounding the cell and of the boundary layers upstream and downstream are reported, together with spectral and correlation analyses of wall-pressure fluctuation measurements. Smoke flow visualisations are reported to provide qualitative insight into some relevant features of the internal flow, namely a large-scale
flow unsteadiness and possible mechanisms driving the rotation of the vortex core. Results are presented for two very dierent regimes: a low Reynolds number case where the incoming boundary layer is laminar and its momentum thickness is small compared to the cell opening, and a moderately high Reynolds number case, where the incoming boundary layer is turbulent and the ratio between the momentum thickness and the opening length is signicantly larger than in the rst case. Implications of the present findings to flow control application of trapped vortex cells are also discussed.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper presents results of an experimental investigation on the flow in a trapped vortex cell embedded into a flat plate and interacting with a zero pressure-gradient boundary layer. The objective of the work is to describe the flow features and elucidate some of the governing physical mechanisms, in light of recent investigations on flow separation control using vortex cells. Hot-wire velocity measurements of the shear layer bounding the cell and of the boundary layers upstream and downstream are reported, together with spectral and correlation analyses of wall-pressure fluctuation measurements. Smoke flow visualisations are reported to provide qualitative insight into some relevant features of the internal flow, namely a large-scale
flow unsteadiness and possible mechanisms driving the rotation of the vortex core. Results are presented for two very dierent regimes: a low Reynolds number case where the incoming boundary layer is laminar and its momentum thickness is small compared to the cell opening, and a moderately high Reynolds number case, where the incoming boundary layer is turbulent and the ratio between the momentum thickness and the opening length is signicantly larger than in the rst case. Implications of the present findings to flow control application of trapped vortex cells are also discussed.
flow unsteadiness and possible mechanisms driving the rotation of the vortex core. Results are presented for two very dierent regimes: a low Reynolds number case where the incoming boundary layer is laminar and its momentum thickness is small compared to the cell opening, and a moderately high Reynolds number case, where the incoming boundary layer is turbulent and the ratio between the momentum thickness and the opening length is signicantly larger than in the rst case. Implications of the present findings to flow control application of trapped vortex cells are also discussed.
2015
SALVATORE, SEDDA; COSTANTINO, SARDU; DAVIDE, LASAGNA; Gaetano, IUSO; SALVATORE, DONELLI RAFFAELE; Fabrizio, De Gregorio
Trapped vortex cell for aeronautical applications: flow analysis through PIV and Wavelet transform tools Proceedings Article
In: 10th Pacific Symposium on Flow Visualization and Image Processing, pp. 10, Gennaro Cardone, napoli – ITA, 2015, ISBN: 978-88-906484-3-4, (Contributo in Atti di convegno).
@inproceedings{inproceedingsi,
title = {Trapped vortex cell for aeronautical applications: flow analysis through PIV
and Wavelet transform tools},
author = {SEDDA SALVATORE and SARDU COSTANTINO and LASAGNA DAVIDE and IUSO Gaetano and DONELLI RAFFAELE SALVATORE and De Gregorio Fabrizio},
url = {http://www.psfvip10.unina.it/Ebook/PSFVIP-10.html#AE0},
isbn = {978-88-906484-3-4},
year = {2015},
date = {2015-06-01},
booktitle = {10th Pacific Symposium on Flow Visualization and Image Processing},
pages = {10},
publisher = {Gennaro Cardone},
address = {napoli - ITA},
abstract = {Results of the application of a trapped vortex cell to an airfoil with the aim of improving the
aerodynamic performances are presented for two complementary experiments arranged at CIRA and at
Politecnico di Torino. In the CIRA experiments, PIV measurements on a simplified configuration were carried
out to characterize the trapped vortical structure and its effect on the separating flow downstream of the cell. In
the experimental investigation at Politecnico di Torino, static pressure distributions were measured around a
complete airfoil model, to yield lift and pitching moment coefficients. Wake surveys were also carried out to
measure the drag. To study the unsteady phenomena inside the cavity pressure fluctuations signals were also
investigated using Kulite sensors. In both experiments, the angle of attack of the airfoil and the Reynolds number
were varied. It is shown that the flow inside the cell is highly unsteady with significant shedding of flow
structures downstream. This phenomenon results in a large region of separated flow, in higher drag and lower
lift. By contrast, the cell flow is considerably stabilized and regularized by applying distributed suction over the
cell wall. As a result, the flow downstream of the cell reattaches and lower drag and larger lift are observed.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Results of the application of a trapped vortex cell to an airfoil with the aim of improving the
aerodynamic performances are presented for two complementary experiments arranged at CIRA and at
Politecnico di Torino. In the CIRA experiments, PIV measurements on a simplified configuration were carried
out to characterize the trapped vortical structure and its effect on the separating flow downstream of the cell. In
the experimental investigation at Politecnico di Torino, static pressure distributions were measured around a
complete airfoil model, to yield lift and pitching moment coefficients. Wake surveys were also carried out to
measure the drag. To study the unsteady phenomena inside the cavity pressure fluctuations signals were also
investigated using Kulite sensors. In both experiments, the angle of attack of the airfoil and the Reynolds number
were varied. It is shown that the flow inside the cell is highly unsteady with significant shedding of flow
structures downstream. This phenomenon results in a large region of separated flow, in higher drag and lower
lift. By contrast, the cell flow is considerably stabilized and regularized by applying distributed suction over the
cell wall. As a result, the flow downstream of the cell reattaches and lower drag and larger lift are observed.
aerodynamic performances are presented for two complementary experiments arranged at CIRA and at
Politecnico di Torino. In the CIRA experiments, PIV measurements on a simplified configuration were carried
out to characterize the trapped vortical structure and its effect on the separating flow downstream of the cell. In
the experimental investigation at Politecnico di Torino, static pressure distributions were measured around a
complete airfoil model, to yield lift and pitching moment coefficients. Wake surveys were also carried out to
measure the drag. To study the unsteady phenomena inside the cavity pressure fluctuations signals were also
investigated using Kulite sensors. In both experiments, the angle of attack of the airfoil and the Reynolds number
were varied. It is shown that the flow inside the cell is highly unsteady with significant shedding of flow
structures downstream. This phenomenon results in a large region of separated flow, in higher drag and lower
lift. By contrast, the cell flow is considerably stabilized and regularized by applying distributed suction over the
cell wall. As a result, the flow downstream of the cell reattaches and lower drag and larger lift are observed.
Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso
Flow field topology of submerged jets with fractal generated turbulence Journal Article
In: PHYSICS OF FLUIDS, vol. 27, 2015.
@article{ 11583_2728382,
title = {Flow field topology of submerged jets with fractal generated turbulence},
author = {Gioacchino Cafiero and Stefano Discetti and Tommaso Astarita},
url = {http://scitation.aip.org/content/aip/journal/pof2},
doi = {10.1063/1.4935185},
year = {2015},
date = {2015-01-01},
journal = {PHYSICS OF FLUIDS},
volume = {27},
publisher = {American Institute of Physics Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gaetano, IUSO; COSTANTINO, SARDU; Sedda, C.
Wind Tunnel Investigation on 1:5 Anuloid Model Miscellaneous
2015, (Altro).
@misc{misc,
title = {Wind Tunnel Investigation on 1:5 Anuloid Model},
author = {IUSO Gaetano and SARDU COSTANTINO and C. Sedda},
year = {2015},
date = {2015-01-01},
volume = {EU Project ANULOID},
abstract = {The model ( scale 1:5 ) of Anuloid aircraft was tested in a large wind tunnel of Mechanical and Aerospace Department-Politecnico di Torino. The evaluation of the aerodynamic performances were performed using a 6 component external balance for the force and moments measurements. Also pressure distributions around the model were assessed. The investigation was conducted varying the incidence for two Reynolds number ( Re=6.8105 and Re=2.1106). In addition flow visualizations were performed using tufts attached to half body on both sides. The model for the wind tunnel investigations has been manufactured by the cooperative work executed by PoliTo e VZLU. The fan flow was not reproduced due the very complex solution for the mounting that would introduce a huge flows interference making the interpretation of the results really questionable. Only the body aerodynamic was as a consequence tested. For negative incidences corresponding to the normal flight conditions the lift is approximately equal to zero while considerable drag takes place. For positive incidences the lift and drag curves change trend as expected showing monotonic increasing of the forces coefficient as the incidence increases. The pitching moment coefficient is always negative and increases nearly in a linear way with the incidence especially for the lower Reynolds number. Reynolds effect is present in particular in the positive range of incidences. The pressure distributions reported in terms of colored maps evidence very 3D complex flow fields changing according with the incidence. Flow visualizations highlighted three-dimensional vortical flows generated especially around the most external annuli on the lower. On the rear part of the upper surface a region of separated and highly unsteady flow is present.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
The model ( scale 1:5 ) of Anuloid aircraft was tested in a large wind tunnel of Mechanical and Aerospace Department-Politecnico di Torino. The evaluation of the aerodynamic performances were performed using a 6 component external balance for the force and moments measurements. Also pressure distributions around the model were assessed. The investigation was conducted varying the incidence for two Reynolds number ( Re=6.8105 and Re=2.1106). In addition flow visualizations were performed using tufts attached to half body on both sides. The model for the wind tunnel investigations has been manufactured by the cooperative work executed by PoliTo e VZLU. The fan flow was not reproduced due the very complex solution for the mounting that would introduce a huge flows interference making the interpretation of the results really questionable. Only the body aerodynamic was as a consequence tested. For negative incidences corresponding to the normal flight conditions the lift is approximately equal to zero while considerable drag takes place. For positive incidences the lift and drag curves change trend as expected showing monotonic increasing of the forces coefficient as the incidence increases. The pitching moment coefficient is always negative and increases nearly in a linear way with the incidence especially for the lower Reynolds number. Reynolds effect is present in particular in the positive range of incidences. The pressure distributions reported in terms of colored maps evidence very 3D complex flow fields changing according with the incidence. Flow visualizations highlighted three-dimensional vortical flows generated especially around the most external annuli on the lower. On the rear part of the upper surface a region of separated and highly unsteady flow is present.
DAVIDE, LASAGNA; Fronges, L.; MATTEO, ORAZI; Gaetano, IUSO
Nonlinear multi-time-delay stochastic estimation: Application to cavity shear layer and turbulent channel flow Journal Article
In: AIAA JOURNAL, vol. 53, pp. 2920-2935, 2015, ISSN: 0001-1452, (Articolo in rivista).
@article{articlee,
title = {Nonlinear multi-time-delay stochastic estimation:
Application to cavity shear layer and turbulent channel flow},
author = {LASAGNA DAVIDE and L. Fronges and ORAZI MATTEO and IUSO Gaetano},
url = {http://arc.aiaa.org/doi/abs/10.2514/1.J053681},
doi = {10.2514/1.J053681},
issn = {0001-1452},
year = {2015},
date = {2015-01-01},
journal = {AIAA JOURNAL},
volume = {53},
pages = {2920-2935},
abstract = {A nonlinear extension of the multi-time-delay stochastic estimation technique is presented. The proposed approach consists in the design of nonlinear prediction filters
based on Artificial Neural Networks or, for smaller problems, on Volterra expansions of the measured wall variable. The application to two different flows is discussed. The first case is the estimation of the temporal dynamics of the velocity fluctuations in a cavity shear layer in low subsonic conditions from wall-pressure measurements. The second case is the estimation of the streamwise velocity fluctuations in the buffer layer of a fully developed turbulent channel flow from wall shear stress measurements. It is shown that the accuracy of the nonlinear technique is application dependent, i.e. it is significantly affected by the underlying nonlinear nature of the flow investigated. In particular, we show that for the cavity shear layer case, the improvement is marginal and it does not appear to be worth the additional computational complexity associated with the nonlinear problem. On the other hand, the improvement in accuracy of the nonlinear estimation of the velocity fluctuations in the wall-turbulence case is significant, owing to the strong nonlinearity of the dynamics in the wall-bounded flow.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A nonlinear extension of the multi-time-delay stochastic estimation technique is presented. The proposed approach consists in the design of nonlinear prediction filters
based on Artificial Neural Networks or, for smaller problems, on Volterra expansions of the measured wall variable. The application to two different flows is discussed. The first case is the estimation of the temporal dynamics of the velocity fluctuations in a cavity shear layer in low subsonic conditions from wall-pressure measurements. The second case is the estimation of the streamwise velocity fluctuations in the buffer layer of a fully developed turbulent channel flow from wall shear stress measurements. It is shown that the accuracy of the nonlinear technique is application dependent, i.e. it is significantly affected by the underlying nonlinear nature of the flow investigated. In particular, we show that for the cavity shear layer case, the improvement is marginal and it does not appear to be worth the additional computational complexity associated with the nonlinear problem. On the other hand, the improvement in accuracy of the nonlinear estimation of the velocity fluctuations in the wall-turbulence case is significant, owing to the strong nonlinearity of the dynamics in the wall-bounded flow.
based on Artificial Neural Networks or, for smaller problems, on Volterra expansions of the measured wall variable. The application to two different flows is discussed. The first case is the estimation of the temporal dynamics of the velocity fluctuations in a cavity shear layer in low subsonic conditions from wall-pressure measurements. The second case is the estimation of the streamwise velocity fluctuations in the buffer layer of a fully developed turbulent channel flow from wall shear stress measurements. It is shown that the accuracy of the nonlinear technique is application dependent, i.e. it is significantly affected by the underlying nonlinear nature of the flow investigated. In particular, we show that for the cavity shear layer case, the improvement is marginal and it does not appear to be worth the additional computational complexity associated with the nonlinear problem. On the other hand, the improvement in accuracy of the nonlinear estimation of the velocity fluctuations in the wall-turbulence case is significant, owing to the strong nonlinearity of the dynamics in the wall-bounded flow.
2014
Probsting, S.; Serpieri, J.; Scarano, F.
Experimental investigation of aerofoil tonal noise generation Journal Article
In: JOURNAL OF FLUID MECHANICS, vol. 747, no. 2, pp. 656–687, 2014.
@article{ 11583_2965992,
title = {Experimental investigation of aerofoil tonal noise generation},
author = {S. Probsting and J. Serpieri and F. Scarano},
doi = {10.1017/jfm.2014.156},
year = {2014},
date = {2014-01-01},
journal = {JOURNAL OF FLUID MECHANICS},
volume = {747},
number = {2},
pages = {656--687},
publisher = {Cambridge University Press},
abstract = {The present study investigates the mechanisms associated with tonal noise emission from a NACA 0012 aerofoil at moderate incidence (0°, 1°, 2° and 4° angle of attack) and with Reynolds numbers ranging from 100 000 to 270 000. Simultaneous time-resolved particle image velocimetry (PIV) of the aeroacoustic source region near the trailing edge and acoustic measurements in the far field are performed in order to establish the correspondence between the flow structure and acoustic emissions. Results of these experiments are presented and analysed in view of past research for a number of selected cases. Characteristics of the acoustic emission and principal features of the average flow field agree with data presented in previous studies on the topic. Time-resolved analysis shows that downstream convecting vortical structures, resulting from growing shear layer instabilities, coherently pass the trailing edge at a frequency equal to that of the dominant tone. Therefore, the scattering of the vortical structures and their associated wall pressure fluctuations are identified as tone generating mechanisms for the cases investigated here. Moreover, wavelet analysis of the acoustic pressure and velocity signals near the trailing edge show a similar periodic amplitude modulation which is associated with multiple tonal peaks in the acoustic spectrum. Periodic amplitude modulation of the acoustic pressure and velocity fluctuations on the pressure side are also observed when transition is forced on the suction side, showing that pressure-side events alone can be the cause.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The present study investigates the mechanisms associated with tonal noise emission from a NACA 0012 aerofoil at moderate incidence (0°, 1°, 2° and 4° angle of attack) and with Reynolds numbers ranging from 100 000 to 270 000. Simultaneous time-resolved particle image velocimetry (PIV) of the aeroacoustic source region near the trailing edge and acoustic measurements in the far field are performed in order to establish the correspondence between the flow structure and acoustic emissions. Results of these experiments are presented and analysed in view of past research for a number of selected cases. Characteristics of the acoustic emission and principal features of the average flow field agree with data presented in previous studies on the topic. Time-resolved analysis shows that downstream convecting vortical structures, resulting from growing shear layer instabilities, coherently pass the trailing edge at a frequency equal to that of the dominant tone. Therefore, the scattering of the vortical structures and their associated wall pressure fluctuations are identified as tone generating mechanisms for the cases investigated here. Moreover, wavelet analysis of the acoustic pressure and velocity signals near the trailing edge show a similar periodic amplitude modulation which is associated with multiple tonal peaks in the acoustic spectrum. Periodic amplitude modulation of the acoustic pressure and velocity fluctuations on the pressure side are also observed when transition is forced on the suction side, showing that pressure-side events alone can be the cause.
MATTEO, ORAZI; DAVIDE, LASAGNA; Gaetano, IUSO
Circular cylinder drag reduction using piezoelectric actuators Journal Article
In: ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE, vol. 1, pp. 27-41, 2014, ISSN: 2287-528X, (Articolo in rivista).
@article{articlef,
title = {Circular cylinder drag reduction using piezoelectric actuators},
author = {ORAZI MATTEO and LASAGNA DAVIDE and IUSO Gaetano},
doi = {10.12989/aas.2014.1.1.027},
issn = {2287-528X},
year = {2014},
date = {2014-01-01},
journal = {ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE},
volume = {1},
pages = {27-41},
abstract = {An active flow control technique based on “smart-tabs” is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing.The effectiveness of the control was tested in pre-critical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An active flow control technique based on “smart-tabs” is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing.The effectiveness of the control was tested in pre-critical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.
Gaetano, IUSO; COSTANTINO, SARDU; Janda, Z.
Report on Coanda Effect: Experimental and CFD analysis Miscellaneous
2014, (Altro).
@misc{miscb,
title = {Report on Coanda Effect: Experimental and CFD analysis},
author = {IUSO Gaetano and SARDU COSTANTINO and Z. Janda},
year = {2014},
date = {2014-01-01},
volume = {Report EU Project ANULOID},
abstract = {The Coanda effect on the lower surface of the Anuloid model (scale 1:22) has been investigated by means of CFD analysis and experiments on a simplified configuration.
The motivations of this investigation are essentially related to the crucial aspect concerning the original maneuvering solution of the aircraft based on the realization of the Coanda effect properly generated on a specific sector of the external annular body on the lower surface. This work was not planned in the submitted proposal and was activated on the light of the suggestions pointed out from the project evaluators focused just on a possible critical behavior of the Coanda effect. On the respect of these suggestions the priority was given in this direction cancelling the work related to the WP 3 " Power means, flight control means and remote (or tethered) control system" and related deliverable.
From this point of view a CFD analysis has been performed by FESA evaluating the effects of the modification of the geometry of the circumferential vanes on the flow evolution around the lower surface of the aircraft. Moreover also the ground effect has been analyzed considering several distances between the model and the ground. The main result of this analysis reports that Coanda effect in the original design is metastable. The new geometry shows instead that a very stable Coanda effect.
The experimental investigation performed by POLITO was focused on the measurements of the pressure distributions around the lower curved surface in the case of the original geometry. Also some modifications of the base of the central body aimed at promoting the Coanda effect were considered mounting different disks on the base that changed the geometry of the annular exit section of the wall jet. A comparison between the experimental data and a model present in the literature representing the Coanda effect in terms of angle of separation as a function of a geometric parameter was also made. Simple flow visualizations were performed using tufts. Furthermore also the effects of asymmetric disks mounting were tested in order to verify the asymmetry of the Coanda effect devoted to the generation of appropriate load aerodynamic distribution on the lower surface aimed at the maneuverability of the aircraft. Finally the effects of the Reynolds number were evaluated.
From this analysis is evidenced that the original geometry does not show any evidence of Coanda effect for all the Reynolds number tested. Introducing the base modifications the flow is more attached to the rounded lower base highlighting the promotion of the Coanda effect that in any case does not involve the whole rounded lower wall of the model},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
The Coanda effect on the lower surface of the Anuloid model (scale 1:22) has been investigated by means of CFD analysis and experiments on a simplified configuration.
The motivations of this investigation are essentially related to the crucial aspect concerning the original maneuvering solution of the aircraft based on the realization of the Coanda effect properly generated on a specific sector of the external annular body on the lower surface. This work was not planned in the submitted proposal and was activated on the light of the suggestions pointed out from the project evaluators focused just on a possible critical behavior of the Coanda effect. On the respect of these suggestions the priority was given in this direction cancelling the work related to the WP 3 ” Power means, flight control means and remote (or tethered) control system” and related deliverable.
From this point of view a CFD analysis has been performed by FESA evaluating the effects of the modification of the geometry of the circumferential vanes on the flow evolution around the lower surface of the aircraft. Moreover also the ground effect has been analyzed considering several distances between the model and the ground. The main result of this analysis reports that Coanda effect in the original design is metastable. The new geometry shows instead that a very stable Coanda effect.
The experimental investigation performed by POLITO was focused on the measurements of the pressure distributions around the lower curved surface in the case of the original geometry. Also some modifications of the base of the central body aimed at promoting the Coanda effect were considered mounting different disks on the base that changed the geometry of the annular exit section of the wall jet. A comparison between the experimental data and a model present in the literature representing the Coanda effect in terms of angle of separation as a function of a geometric parameter was also made. Simple flow visualizations were performed using tufts. Furthermore also the effects of asymmetric disks mounting were tested in order to verify the asymmetry of the Coanda effect devoted to the generation of appropriate load aerodynamic distribution on the lower surface aimed at the maneuverability of the aircraft. Finally the effects of the Reynolds number were evaluated.
From this analysis is evidenced that the original geometry does not show any evidence of Coanda effect for all the Reynolds number tested. Introducing the base modifications the flow is more attached to the rounded lower base highlighting the promotion of the Coanda effect that in any case does not involve the whole rounded lower wall of the model
The motivations of this investigation are essentially related to the crucial aspect concerning the original maneuvering solution of the aircraft based on the realization of the Coanda effect properly generated on a specific sector of the external annular body on the lower surface. This work was not planned in the submitted proposal and was activated on the light of the suggestions pointed out from the project evaluators focused just on a possible critical behavior of the Coanda effect. On the respect of these suggestions the priority was given in this direction cancelling the work related to the WP 3 ” Power means, flight control means and remote (or tethered) control system” and related deliverable.
From this point of view a CFD analysis has been performed by FESA evaluating the effects of the modification of the geometry of the circumferential vanes on the flow evolution around the lower surface of the aircraft. Moreover also the ground effect has been analyzed considering several distances between the model and the ground. The main result of this analysis reports that Coanda effect in the original design is metastable. The new geometry shows instead that a very stable Coanda effect.
The experimental investigation performed by POLITO was focused on the measurements of the pressure distributions around the lower curved surface in the case of the original geometry. Also some modifications of the base of the central body aimed at promoting the Coanda effect were considered mounting different disks on the base that changed the geometry of the annular exit section of the wall jet. A comparison between the experimental data and a model present in the literature representing the Coanda effect in terms of angle of separation as a function of a geometric parameter was also made. Simple flow visualizations were performed using tufts. Furthermore also the effects of asymmetric disks mounting were tested in order to verify the asymmetry of the Coanda effect devoted to the generation of appropriate load aerodynamic distribution on the lower surface aimed at the maneuverability of the aircraft. Finally the effects of the Reynolds number were evaluated.
From this analysis is evidenced that the original geometry does not show any evidence of Coanda effect for all the Reynolds number tested. Introducing the base modifications the flow is more attached to the rounded lower base highlighting the promotion of the Coanda effect that in any case does not involve the whole rounded lower wall of the model
DAVIDE, LASAGNA; MATTEO, ORAZI; Gaetano, IUSO
Streamwise vortices originating from synthetic jet-turbulent boundary layer interaction Journal Article
In: FLUID DYNAMICS RESEARCH, vol. 46, pp. 26, 2014, ISSN: 0169-5983, (Articolo in rivista).
@article{articleg,
title = {Streamwise vortices originating from synthetic jet-turbulent boundary layer interaction},
author = {LASAGNA DAVIDE and ORAZI MATTEO and IUSO Gaetano},
doi = {10.1088/0169-5983/46/1/015501},
issn = {0169-5983},
year = {2014},
date = {2014-01-01},
journal = {FLUID DYNAMICS RESEARCH},
volume = {46},
pages = {26},
abstract = {The interaction between a flat plate turbulent boundary layer and a synthetic jet issuing from a rectangular slot slanted with respect to the free stream was studied experimentally using Digital Particle Image Velocimetry (DPIV). Instantaneous flow fields were sampled in a cross-plane downstream of the slot. Results concerning the effects of varying the synthetic jet velocity ratio at fixed stroke length L0 and yaw angle, and the effects of varying the orifice yaw angle at a fixed frequency are presented. The formation of a pair of counter-rotating vortical structures, completely embedded in the boundary layer, was observed in the mean flow field when the slot was aligned with the cross-flow. As the slot yaw angle was increased the leeward vortex intensified while the other became weaker. These vortical structures are the traces of streamwise vortices forming upstream, at the slot exit, during the blowing phases. As the jet velocity ratio and the slot yaw angle were increased the vortices grew in size and intensity. The vortex identification technique showed that these vortical structures are intermittently present in the instantaneous flow fields with a percentage growing with the frequency but not influenced by the yaw angle. Conditional averages
showed that while the rotational core of the identified vortices is nearly unaffected, their outer region is greatly modified and grows in size and intensity as the jet velocity ratio and the yaw angle increased.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The interaction between a flat plate turbulent boundary layer and a synthetic jet issuing from a rectangular slot slanted with respect to the free stream was studied experimentally using Digital Particle Image Velocimetry (DPIV). Instantaneous flow fields were sampled in a cross-plane downstream of the slot. Results concerning the effects of varying the synthetic jet velocity ratio at fixed stroke length L0 and yaw angle, and the effects of varying the orifice yaw angle at a fixed frequency are presented. The formation of a pair of counter-rotating vortical structures, completely embedded in the boundary layer, was observed in the mean flow field when the slot was aligned with the cross-flow. As the slot yaw angle was increased the leeward vortex intensified while the other became weaker. These vortical structures are the traces of streamwise vortices forming upstream, at the slot exit, during the blowing phases. As the jet velocity ratio and the slot yaw angle were increased the vortices grew in size and intensity. The vortex identification technique showed that these vortical structures are intermittently present in the instantaneous flow fields with a percentage growing with the frequency but not influenced by the yaw angle. Conditional averages
showed that while the rotational core of the identified vortices is nearly unaffected, their outer region is greatly modified and grows in size and intensity as the jet velocity ratio and the yaw angle increased.
showed that while the rotational core of the identified vortices is nearly unaffected, their outer region is greatly modified and grows in size and intensity as the jet velocity ratio and the yaw angle increased.
2013
MATTEO, ORAZI; DAVIDE, LASAGNA; Gaetano, IUSO
Circular cylinder drag reduction using piezoelectric actuators Proceedings Article
In: Titolo volume non avvalorato, pp. 17, 2013, (Contributo in Atti di convegno).
@inproceedings{inproceedingsk,
title = {Circular cylinder drag reduction using piezoelectric actuators},
author = {ORAZI MATTEO and LASAGNA DAVIDE and IUSO Gaetano},
year = {2013},
date = {2013-06-01},
booktitle = {Titolo volume non avvalorato},
pages = {17},
abstract = {An active flow control technique based on “smart-tabs” is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing. The effectiveness of the control was tested in precritical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
An active flow control technique based on “smart-tabs” is proposed to delay flow separation on a circular cylinder. The actuators are retractable and orientable multilayer piezoelectric tabs which protrude perpendicularly from the model surface. They are mounted along the spanwise direction with constant spacing. The effectiveness of the control was tested in precritical and in post-critical regime by evaluating the effects of several control parameters of the tabs like frequency, amplitude, height, angular position and plate incidence with respect to the local flow. Measurements of the mean static pressure distribution around the cylinder were used to estimate the pressure drag coefficient. The maximum drag reduction achieved in the pre-critical regime was of the order of 30%, whereas in the post-critical regime was about 10%, 3% of which due to active forcing. Furthermore, pressure fluctuation measurements were performed and spectral analysis indicated an almost complete suppression of the vortex shedding in active forcing conditions.
MATTEO, ORAZI; DAVIDE, LASAGNA; Gaetano, IUSO
Circular cylinder drag reduction using piezoelectric actuators Journal Article
In: ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE, vol. 1, pp. 27-41, 2013, ISSN: 2287-528X, (Articolo in rivista).
@article{articleh,
title = {Circular cylinder drag reduction using piezoelectric actuators},
author = {ORAZI MATTEO and LASAGNA DAVIDE and IUSO Gaetano},
doi = {10.12989/aas.2013.1.1.000},
issn = {2287-528X},
year = {2013},
date = {2013-01-01},
journal = {ADVANCES IN AIRCRAFT AND SPACECRAFT SCIENCE},
volume = {1},
pages = {27-41},
abstract = {An active flow control technique based on “smart tabs” is proposed to delay flow separation on a circular cylinder.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An active flow control technique based on “smart tabs” is proposed to delay flow separation on a circular cylinder.
DAVIDE, LASAGNA; MATTEO, ORAZI; Gaetano, IUSO
Multi-time delay, multi-point Linear Stochastic Estimation of a cavity shear layer velocity from wall-pressure measurements Journal Article
In: PHYSICS OF FLUIDS, vol. 25, pp. 29, 2013, ISSN: 1070-6631, (Articolo in rivista).
@article{articlei,
title = {Multi-time delay, multi-point Linear Stochastic Estimation of a cavity shear layer velocity from wall-pressure measurements},
author = {LASAGNA DAVIDE and ORAZI MATTEO and IUSO Gaetano},
url = {http://link.aip.org/link/?PHF/25/017101},
doi = {10.1063/1.4774337},
issn = {1070-6631},
year = {2013},
date = {2013-01-01},
journal = {PHYSICS OF FLUIDS},
volume = {25},
pages = {29},
abstract = {Multi-time-delay Linear Stochastic Estimation (MTD-LSE) technique
is thoroughly described, focusing on its fundamental properties and potentialities. In the multi-time-delay ap-
proach, the estimate of the temporal evolution of the velocity at a given location in the flow field is obtained
from multiple past samples of the unconditional sources. The technique is applied to estimate the velocity in
a cavity shear layer flow, based on wall-pressure measurements from multiple sensors.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Multi-time-delay Linear Stochastic Estimation (MTD-LSE) technique
is thoroughly described, focusing on its fundamental properties and potentialities. In the multi-time-delay ap-
proach, the estimate of the temporal evolution of the velocity at a given location in the flow field is obtained
from multiple past samples of the unconditional sources. The technique is applied to estimate the velocity in
a cavity shear layer flow, based on wall-pressure measurements from multiple sensors.
is thoroughly described, focusing on its fundamental properties and potentialities. In the multi-time-delay ap-
proach, the estimate of the temporal evolution of the velocity at a given location in the flow field is obtained
from multiple past samples of the unconditional sources. The technique is applied to estimate the velocity in
a cavity shear layer flow, based on wall-pressure measurements from multiple sensors.
2012
MATTEO, ORAZI; DAVIDE, LASAGNA; Gaetano, IUSO
Bluff Body Flow Control Through Piezoelectric Actuators Proceedings Article
In: Titolo volume non avvalorato, 2012, (Abstract in Atti di convegno).
@inproceedings{inproceedingsn,
title = {Bluff Body Flow Control Through Piezoelectric Actuators},
author = {ORAZI MATTEO and LASAGNA DAVIDE and IUSO Gaetano},
year = {2012},
date = {2012-12-01},
booktitle = {Titolo volume non avvalorato},
abstract = {Delay separation from bluff bodies leads to drag reduction. An active flow control technique based on piezoelectric actuators has been arranged on a 2D cilynder in subsonic flow. Experimental investigation in precritical and postcritical conditions of the flow has been conducted varying the configurations of the actuators. Drag reduction up to 10% without a complete optimization of the flow control parameters have been obtained.},
note = {Abstract in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Delay separation from bluff bodies leads to drag reduction. An active flow control technique based on piezoelectric actuators has been arranged on a 2D cilynder in subsonic flow. Experimental investigation in precritical and postcritical conditions of the flow has been conducted varying the configurations of the actuators. Drag reduction up to 10% without a complete optimization of the flow control parameters have been obtained.
DAVIDE, LASAGNA; MATTEO, ORAZI; Gaetano, IUSO
Control of the flow in a trapped vortex cell Proceedings Article
In: Titolo volume non avvalorato, 2012, (Abstract in Atti di convegno).
@inproceedings{inproceedingso,
title = {Control of the flow in a trapped vortex cell},
author = {LASAGNA DAVIDE and ORAZI MATTEO and IUSO Gaetano},
year = {2012},
date = {2012-12-01},
booktitle = {Titolo volume non avvalorato},
abstract = {A trapped vortex cell, (TVC), is a flow control device consisting in a cavity embedded on the upper surface of an airfoil, designed to trap a steady vortex. By the interaction with the vortical cell's
ow, the incoming boundary layer becomes more energetic, and it is thus less prone to separation. Wind tunnel tests by De Gregorio et al. [2] and by Lasagna et al. [1] have shown that to make this control effective the cavity flow itself must be the target of a control action. In particular, the latter authors have shown that
the airfoil drag can be substantially reduced with respect to the clean airfoil by applying suction into the cavity region and that this technique is superior to a classical boundary layer suction system, for the same suction flow rate. One goal of this work is to further investigate on the drag reduction mechanism of the TVC with suction technique. Furthermore, a second control technique, based on a synthetic jet device (SJ) which injects momentum into the cavity in order to energize the vortical cell's flow, is considered. Interest in this technique is raised since it is far more effcient than steady suction.},
note = {Abstract in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
A trapped vortex cell, (TVC), is a flow control device consisting in a cavity embedded on the upper surface of an airfoil, designed to trap a steady vortex. By the interaction with the vortical cell’s
ow, the incoming boundary layer becomes more energetic, and it is thus less prone to separation. Wind tunnel tests by De Gregorio et al. [2] and by Lasagna et al. [1] have shown that to make this control effective the cavity flow itself must be the target of a control action. In particular, the latter authors have shown that
the airfoil drag can be substantially reduced with respect to the clean airfoil by applying suction into the cavity region and that this technique is superior to a classical boundary layer suction system, for the same suction flow rate. One goal of this work is to further investigate on the drag reduction mechanism of the TVC with suction technique. Furthermore, a second control technique, based on a synthetic jet device (SJ) which injects momentum into the cavity in order to energize the vortical cell’s flow, is considered. Interest in this technique is raised since it is far more effcient than steady suction.
ow, the incoming boundary layer becomes more energetic, and it is thus less prone to separation. Wind tunnel tests by De Gregorio et al. [2] and by Lasagna et al. [1] have shown that to make this control effective the cavity flow itself must be the target of a control action. In particular, the latter authors have shown that
the airfoil drag can be substantially reduced with respect to the clean airfoil by applying suction into the cavity region and that this technique is superior to a classical boundary layer suction system, for the same suction flow rate. One goal of this work is to further investigate on the drag reduction mechanism of the TVC with suction technique. Furthermore, a second control technique, based on a synthetic jet device (SJ) which injects momentum into the cavity in order to energize the vortical cell’s flow, is considered. Interest in this technique is raised since it is far more effcient than steady suction.
DAVIDE, LASAGNA; MATTEO, ORAZI; Gaetano, IUSO
Wall-pressure based Multi-Time-Delay Linear StochasticEstimation Proceedings Article
In: Titolo volume non avvalorato, 2012, (Contributo in Atti di convegno).
@inproceedings{inproceedingsm,
title = {Wall-pressure based Multi-Time-Delay Linear StochasticEstimation},
author = {LASAGNA DAVIDE and ORAZI MATTEO and IUSO Gaetano},
year = {2012},
date = {2012-09-01},
booktitle = {Titolo volume non avvalorato},
abstract = {Linear Stochastic Estimation (LSE) is a well known, widely used data analysis technique, offering quantitative insight into the dynamics of coherent structures12. In the wall-pressure based classical LSE approach the velocity estimate u(t) is obtained from the wall-pressure p(t) as u(t)_LSE = bo*p(t), i.e. by using a single sam-
ple of the wall-pressure time history. By contrast, in the Multi-Time-Delay (MTD) technique more than one past samples is used simultaneously for the estimate.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Linear Stochastic Estimation (LSE) is a well known, widely used data analysis technique, offering quantitative insight into the dynamics of coherent structures12. In the wall-pressure based classical LSE approach the velocity estimate u(t) is obtained from the wall-pressure p(t) as u(t)_LSE = bo*p(t), i.e. by using a single sam-
ple of the wall-pressure time history. By contrast, in the Multi-Time-Delay (MTD) technique more than one past samples is used simultaneously for the estimate.
ple of the wall-pressure time history. By contrast, in the Multi-Time-Delay (MTD) technique more than one past samples is used simultaneously for the estimate.
Orazi, M.; Lasagna, D.; Iuso, G.
Bluff Body Flow Control Through Piezoelectric Actuators Conference
Titolo volume non avvalorato, 2012.
@conference{ 11583_2503185,
title = {Bluff Body Flow Control Through Piezoelectric Actuators},
author = {M. Orazi and D. Lasagna and G. Iuso},
year = {2012},
date = {2012-01-01},
booktitle = {Titolo volume non avvalorato},
abstract = {Delay separation from bluff bodies leads to drag reduction. An active flow control technique based on piezoelectric actuators has been arranged on a 2D cilynder in subsonic flow. Experimental investigation in precritical and postcritical conditions of the flow has been conducted varying the configurations of the actuators. Drag reduction up to 10% without a complete optimization of the flow control parameters have been obtained.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Delay separation from bluff bodies leads to drag reduction. An active flow control technique based on piezoelectric actuators has been arranged on a 2D cilynder in subsonic flow. Experimental investigation in precritical and postcritical conditions of the flow has been conducted varying the configurations of the actuators. Drag reduction up to 10% without a complete optimization of the flow control parameters have been obtained.
Gaetano, IUSO; DAVIDE, LASAGNA; MATTEO, ORAZI; SCHULLER, M.; LIPOWSKI, M.
SYNTHETIC JET AERODYNAMIC CHARACTERIZATION Miscellaneous
2012, (Altro).
@misc{miscc,
title = {SYNTHETIC JET AERODYNAMIC CHARACTERIZATION},
author = {IUSO Gaetano and LASAGNA DAVIDE and ORAZI MATTEO and M. SCHULLER and M. LIPOWSKI},
year = {2012},
date = {2012-01-01},
pages = {28},
abstract = {This document, as Output O 2.2.1-33 of the GRA – “Low-Noise Configuration” (LNC) Project of the “Clean Sky” JTI, is issued according to the Technical Annex 1B to the Grant Agreement 2011 of the GRA ITD. The document present results related with the experimental characterization of the synthetic jets actuators manufactured by the research group of Fraunhofer. The oscillating surface of the actuator is covered by a circular piezoelectric element that generates oscillating flow through a circular orifice having a diameter equal to 0.5mm. The test panel has three distinct actuators that can be activated singularly or can also be used in a multiple actuation. The investigation has been performed in still air conditions. Velocity measurements on the jets axis have been carried out varying the voltage amplitude and the oscillation frequency for each single actuator. A miniaturized total pressure probe having external diameter equal to 0.3 mm was used. Maximum velocity on the jet axis of the order of 20 m/s were measured for the three actuators in correspondence of the second resonance frequency of the actuators. Several distances from the exit section were tested, up to 40 diameters downstream. A combination of the two closest actuators was surveyed measuring the velocity distribution along the direction connecting the two orifice centres for x/d = 10 and x/d=20. An inclination of the three jets axis respect to the geometric centre of the orifice was finally highlighted.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
This document, as Output O 2.2.1-33 of the GRA – “Low-Noise Configuration” (LNC) Project of the “Clean Sky” JTI, is issued according to the Technical Annex 1B to the Grant Agreement 2011 of the GRA ITD. The document present results related with the experimental characterization of the synthetic jets actuators manufactured by the research group of Fraunhofer. The oscillating surface of the actuator is covered by a circular piezoelectric element that generates oscillating flow through a circular orifice having a diameter equal to 0.5mm. The test panel has three distinct actuators that can be activated singularly or can also be used in a multiple actuation. The investigation has been performed in still air conditions. Velocity measurements on the jets axis have been carried out varying the voltage amplitude and the oscillation frequency for each single actuator. A miniaturized total pressure probe having external diameter equal to 0.3 mm was used. Maximum velocity on the jet axis of the order of 20 m/s were measured for the three actuators in correspondence of the second resonance frequency of the actuators. Several distances from the exit section were tested, up to 40 diameters downstream. A combination of the two closest actuators was surveyed measuring the velocity distribution along the direction connecting the two orifice centres for x/d = 10 and x/d=20. An inclination of the three jets axis respect to the geometric centre of the orifice was finally highlighted.
Gaetano, IUSO; MARCO, GRIVET FETA’
DESIGN OF A ROTATING CYLINDER FOR RIBLETS TECHNOLOGY TESTING Miscellaneous
2012, (Altro).
@misc{miscd,
title = {DESIGN OF A ROTATING CYLINDER FOR RIBLETS TECHNOLOGY TESTING},
author = {IUSO Gaetano and GRIVET FETA' MARCO},
year = {2012},
date = {2012-01-01},
pages = {25},
abstract = {The present document, as Output O2.2.6-10 of the GRA-LNC Project of the “Clean Sky” JTI, is issued according to the Technical Annex 1B to the Grant Agreement 2011 of the GRA ITD. The objective of the present report is the mechanical design of the facility to be manufactured and used for a reliable evaluation of the friction drag of ribs surfaces. The definition of the present design follows the previous analysis reported in the Deliverable D2.2.6-04 [1].},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
The present document, as Output O2.2.6-10 of the GRA-LNC Project of the “Clean Sky” JTI, is issued according to the Technical Annex 1B to the Grant Agreement 2011 of the GRA ITD. The objective of the present report is the mechanical design of the facility to be manufactured and used for a reliable evaluation of the friction drag of ribs surfaces. The definition of the present design follows the previous analysis reported in the Deliverable D2.2.6-04 [1].
2011
Gaetano, IUSO; DAVIDE, LASAGNA; MATTEO, ORAZI
“Definition of tests on Riblets performence through a rotating cylinder” Miscellaneous
2011, (Altro).
@misc{misce,
title = {"Definition of tests on Riblets performence through a rotating cylinder"},
author = {IUSO Gaetano and LASAGNA DAVIDE and ORAZI MATTEO},
year = {2011},
date = {2011-01-01},
pages = {1-28},
abstract = {The document describes an experimental facility and provides relevant tests requirements to evaluate the performance of riblets surfaces in terms of skin friction drag reduction. The concerned activity has been planned, in the frame of WP 2.2.6, to validate this very promising passive drag reduction technology, considering both conventional and innovative riblets configurations to be tested.},
note = {Altro},
keywords = {},
pubstate = {published},
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The document describes an experimental facility and provides relevant tests requirements to evaluate the performance of riblets surfaces in terms of skin friction drag reduction. The concerned activity has been planned, in the frame of WP 2.2.6, to validate this very promising passive drag reduction technology, considering both conventional and innovative riblets configurations to be tested.
MATTEO, ORAZI; DAVIDE, LASAGNA; Gaetano, IUSO
Virtual Shaping on NACA 0015 by Means of a High Momentum Coefficient Synthetic Jet Journal Article
In: INTERNATIONAL JOURNAL OF FLOW CONTROL, vol. 3, pp. 255-276, 2011, ISSN: 1756-8250, (Articolo in rivista).
@article{articlej,
title = {Virtual Shaping on NACA 0015 by Means of a High Momentum Coefficient Synthetic Jet},
author = {ORAZI MATTEO and LASAGNA DAVIDE and IUSO Gaetano},
doi = {10.1260/1756-8250.3.4.255},
issn = {1756-8250},
year = {2011},
date = {2011-01-01},
journal = {INTERNATIONAL JOURNAL OF FLOW CONTROL},
volume = {3},
pages = {255-276},
abstract = {Results concerning flow control on a NACA 0015 airfoil using high power synthetic jets are presented for low incidences and for Reynolds numbers ranging from 132000 to 425000. The forcing was operated through a spanwise slit positioned near the leading edge at x/c=1.25% or at x/c=10% on the upper surface. Static pressure distribution measurements around the airfoil, wake surveys and smoke flow visualizations were performed. Pressure distributions were significantly modified around the injection location, showing an area of intense suction which increased the lift and strongly affected the drag. Flow visualizations highlighted that the intense suction was due to a virtual shaping effect caused by the formation of a recirculation bubble capable of displacing the streamlines. Low momentum deficits in the wake velocity distributions and, in certain conditions, jet-like flow was observed for the forced cases. Finally, a scaling law relating the bubble size to the forcing intensity is proposed.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Results concerning flow control on a NACA 0015 airfoil using high power synthetic jets are presented for low incidences and for Reynolds numbers ranging from 132000 to 425000. The forcing was operated through a spanwise slit positioned near the leading edge at x/c=1.25% or at x/c=10% on the upper surface. Static pressure distribution measurements around the airfoil, wake surveys and smoke flow visualizations were performed. Pressure distributions were significantly modified around the injection location, showing an area of intense suction which increased the lift and strongly affected the drag. Flow visualizations highlighted that the intense suction was due to a virtual shaping effect caused by the formation of a recirculation bubble capable of displacing the streamlines. Low momentum deficits in the wake velocity distributions and, in certain conditions, jet-like flow was observed for the forced cases. Finally, a scaling law relating the bubble size to the forcing intensity is proposed.
DAVIDE, LASAGNA; R., DONELLI; F., DE GREGORIO; Gaetano, IUSO
Effects of a trapped vortex cell on thick wing profile Journal Article
In: EXPERIMENTS IN FLUIDS, vol. 51, pp. 1369-1384, 2011, ISSN: 0723-4864, (Articolo in rivista).
@article{articlek,
title = {Effects of a trapped vortex cell on thick wing profile},
author = {LASAGNA DAVIDE and DONELLI R. and DE GREGORIO F. and IUSO Gaetano},
doi = {10.1007/s00348-011-1160-9},
issn = {0723-4864},
year = {2011},
date = {2011-01-01},
journal = {EXPERIMENTS IN FLUIDS},
volume = {51},
pages = {1369-1384},
abstract = {Experimental investigation on the effects originated from a trapped vortex cell on the NACA0024 airfoil.},
note = {Articolo in rivista},
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pubstate = {published},
tppubtype = {article}
}
Experimental investigation on the effects originated from a trapped vortex cell on the NACA0024 airfoil.
2010
DAVIDE, LASAGNA; Gaetano, IUSO
Flow control on wing by means of trapped vortex cell Proceedings Article
In: Titolo volume non avvalorato, pp. 1-2, 2010, (Contributo in Atti di convegno).
@inproceedings{inproceedingsp,
title = {Flow control on wing by means of trapped vortex cell},
author = {LASAGNA DAVIDE and IUSO Gaetano},
year = {2010},
date = {2010-09-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-2},
note = {Contributo in Atti di convegno},
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}
Gaetano, IUSO; DAVIDE, LASAGNA; F., DE GREGORIO
Technical Specification for a Synthetic Jet Experiment Miscellaneous
2010, (Altro).
@misc{miscf,
title = {Technical Specification for a Synthetic Jet Experiment},
author = {IUSO Gaetano and LASAGNA DAVIDE and DE GREGORIO F.},
year = {2010},
date = {2010-01-01},
pages = {1-38},
abstract = {Viene controllata la separazione della corrente attorno al profilo alare Naca 0024 mediante getti sintetici alle elvate incidenze.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Viene controllata la separazione della corrente attorno al profilo alare Naca 0024 mediante getti sintetici alle elvate incidenze.
Gaetano, IUSO; DAVIDE, LASAGNA; F., De Gregorio; R., Donelli
Report on detailed review of wind tunnel data Miscellaneous
2010, (Altro).
@misc{miscg,
title = {Report on detailed review of wind tunnel data},
author = {IUSO Gaetano and LASAGNA DAVIDE and De Gregorio F. and Donelli R.},
url = {http://www.vortexcell2050.org/},
year = {2010},
date = {2010-01-01},
pages = {2-55},
abstract = {Controllo del flusso attorno al profilo alare NACA0024 mediante la tecnica del " trapped vortex cell" al fine di migliorare le prestazioni aerodinamiche del profilo alare.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Controllo del flusso attorno al profilo alare NACA0024 mediante la tecnica del ” trapped vortex cell” al fine di migliorare le prestazioni aerodinamiche del profilo alare.
2009
Gaetano, IUSO; VITTORIA, SALVETTI MARIA; R., Tognaccini; B., Mele
State of Art Review of Aerodynamic Drag Reduction Technologies [GRA-2.2.6-DL(D2.2.6-02)-Air Green-TECH-209064 A] Miscellaneous
2009, (Altro).
@misc{misch,
title = {State of Art Review of Aerodynamic Drag Reduction Technologies [GRA-2.2.6-DL(D2.2.6-02)-Air Green-TECH-209064 A]},
author = {IUSO Gaetano and SALVETTI MARIA VITTORIA and Tognaccini R. and Mele B.},
year = {2009},
date = {2009-01-01},
pages = {1-59},
abstract = {Analisi dello stato dell'arte delle tecniche finalizzate alla riduzione della resistenza aerodimanica dei velivoli.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Analisi dello stato dell’arte delle tecniche finalizzate alla riduzione della resistenza aerodimanica dei velivoli.
Gaetano, IUSO; DAVIDE, LASAGNA; R., DONELLI; F., DE GREGORIO
2009, (Altro).
@misc{misci,
title = {Summary of wind tunnel tests, preliminary analysisVCell 2050 - VI EU Program. Contract No: AST4-CT-2005-012139. Deliverable 8.2.10 – December 2009},
author = {IUSO Gaetano and LASAGNA DAVIDE and DONELLI R. and DE GREGORIO F.},
url = {http://www.vortexcell2050.org/},
year = {2009},
date = {2009-01-01},
pages = {1-26},
abstract = {Controllo del flusso attorno al profilo alare NACA0024 mediante la tecnica del "trapped vortex cavity" al fine di migliorare le prestazioni aerodinamiche del profilo alare.},
note = {Altro},
keywords = {},
pubstate = {published},
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}
Controllo del flusso attorno al profilo alare NACA0024 mediante la tecnica del “trapped vortex cavity” al fine di migliorare le prestazioni aerodinamiche del profilo alare.
2008
Maria, DI CICCA Gaetano; Gaetano, IUSO
Large-Scale Manipulation of a Turbulent Boundary Layer by Means of a 2D Synthetic Jet Proceedings Article
In: Titolo volume non avvalorato, pp. 1-6, 2008, ISBN: 0953399192, (Contributo in Atti di convegno).
@inproceedings{inproceedingsq,
title = {Large-Scale Manipulation of a Turbulent Boundary Layer by Means of a 2D Synthetic Jet},
author = {DI CICCA Gaetano Maria and IUSO Gaetano},
isbn = {0953399192},
year = {2008},
date = {2008-09-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-6},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
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}
CANNATA, M.; Gaetano, IUSO
Transversally injected synthetic jets for wall turbulence control Proceedings Article
In: Titolo volume non avvalorato, 2008, (Contributo in Atti di convegno).
@inproceedings{inproceedingsr,
title = {Transversally injected synthetic jets for wall turbulence control},
author = {M. CANNATA and IUSO Gaetano},
year = {2008},
date = {2008-09-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
MARCO, CANNATA; Gaetano, IUSO
Spanwise directed synthetic jets for wall turbulence control Proceedings Article
In: 4th AIAA Flow Control Conference 2008, Curran Associates, Inc., – -, 2008, ISBN: 9781605603698, (Contributo in Atti di convegno).
@inproceedings{inproceedingss,
title = {Spanwise directed synthetic jets for wall turbulence control},
author = {CANNATA MARCO and IUSO Gaetano},
isbn = {9781605603698},
year = {2008},
date = {2008-06-01},
booktitle = {4th AIAA Flow Control Conference 2008},
publisher = {Curran Associates, Inc.},
address = {- -},
abstract = {This investigation focuses on the effects produced by the forcing of adjacent synthetic jets arrays injected tangentially to the wall in the spanwise direction of a fully developed turbulent channel flow. The effects of the forcing frequency and of the synthetic jets arrays configuration are investigated. Instantaneous wall shear stress and streamwise velocity fluctuations give evidence of drag reduction and also turbulence attenuation up to 20%. The benefits of the forcing are remarkable along the channel axis up to 153 half channel height and are persistent in the spanwise direction up to a quarter of channel width. The forcing frequencies producing drag reduction and turbulence attenuation are of the order of few Hertz at the Reynolds number investigated (Re_tau=180).},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
This investigation focuses on the effects produced by the forcing of adjacent synthetic jets arrays injected tangentially to the wall in the spanwise direction of a fully developed turbulent channel flow. The effects of the forcing frequency and of the synthetic jets arrays configuration are investigated. Instantaneous wall shear stress and streamwise velocity fluctuations give evidence of drag reduction and also turbulence attenuation up to 20%. The benefits of the forcing are remarkable along the channel axis up to 153 half channel height and are persistent in the spanwise direction up to a quarter of channel width. The forcing frequencies producing drag reduction and turbulence attenuation are of the order of few Hertz at the Reynolds number investigated (Re_tau=180).
2007
Maria, DI CICCA Gaetano; CANNATA, M.; Gaetano, IUSO
On the Structure Modification of a Turbulent Boundary Layer Under the Action of a Yawed Synthetic Jet Proceedings Article
In: Titolo volume non avvalorato, pp. 1-11, 2007, (Contributo in Atti di convegno).
@inproceedings{inproceedingsv,
title = {On the Structure Modification of a Turbulent Boundary Layer Under the Action of a Yawed Synthetic Jet},
author = {DI CICCA Gaetano Maria and M. CANNATA and IUSO Gaetano},
year = {2007},
date = {2007-09-01},
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note = {Contributo in Atti di convegno},
keywords = {},
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IUSO, G.; CANNATA, M; CICCA, G. M. DI
Channel flow control by means of spanwise wall-flow oscillations generated by synthetic jets Conference
Titolo volume non avvalorato, 2007, ISBN: 9788889720691.
@conference{ 11583_1641783,
title = {Channel flow control by means of spanwise wall-flow oscillations generated by synthetic jets},
author = {G. IUSO and M CANNATA and G. M. DI CICCA},
isbn = {9788889720691},
year = {2007},
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Maria, DI CICCA Gaetano; Gaetano, IUSO
On the Near Field of an Axisymmetric Synthetic Jet Journal Article
In: FLUID DYNAMICS RESEARCH, vol. 39, pp. 673-693, 2007, ISSN: 0169-5983, (Articolo in rivista).
@article{articlel,
title = {On the Near Field of an Axisymmetric Synthetic Jet},
author = {DI CICCA Gaetano Maria and IUSO Gaetano},
doi = {10.1016/i.fluiddyn.2007.03.002},
issn = {0169-5983},
year = {2007},
date = {2007-01-01},
journal = {FLUID DYNAMICS RESEARCH},
volume = {39},
pages = {673-693},
abstract = {The axisymmetric synthetic jet produced by an oscillating piston has been investigated experimentally. The study was performed in water using digital particle image velocimetry for the instantaneous velocity planar measurements. The near field, up to x/d0 ≈ 6, was investigated for three different Reynolds numbers. The self-similarity of the flow field is already fully reached for the mean velocity profiles at x/d0 ≈ 4 while longer distances are needed for the turbulent intensity profiles. The flow structure investigation shows that a single vortex ring or a train of vortex rings characterizes the near field during the blowing phase, depending on the jet flow parameters. The details of the flow field have also been described in terms of phase-averaged flow analysis and of triple decomposition of the instantaneous velocity field. The near flow fields investigated do not seem to be influenced by the Reynolds number.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The axisymmetric synthetic jet produced by an oscillating piston has been investigated experimentally. The study was performed in water using digital particle image velocimetry for the instantaneous velocity planar measurements. The near field, up to x/d0 ≈ 6, was investigated for three different Reynolds numbers. The self-similarity of the flow field is already fully reached for the mean velocity profiles at x/d0 ≈ 4 while longer distances are needed for the turbulent intensity profiles. The flow structure investigation shows that a single vortex ring or a train of vortex rings characterizes the near field during the blowing phase, depending on the jet flow parameters. The details of the flow field have also been described in terms of phase-averaged flow analysis and of triple decomposition of the instantaneous velocity field. The near flow fields investigated do not seem to be influenced by the Reynolds number.
Gaetano, IUSO; Maria, DI CICCA Gaetano
Interaction of synthetic jets with a fully developed turbulent channel flow Journal Article
In: JOURNAL OF TURBULENCE, vol. 8:1, pp. 1-33, 2007, ISSN: 1468-5248, (Articolo in rivista).
@article{articlem,
title = {Interaction of synthetic jets with a fully developed turbulent channel flow},
author = {IUSO Gaetano and DI CICCA Gaetano Maria},
url = {http://dx.doi.org/10.1080/14685240601110088},
doi = {10.1080/14685240601110088},
issn = {1468-5248},
year = {2007},
date = {2007-01-01},
journal = {JOURNAL OF TURBULENCE},
volume = {8:1},
pages = {1-33},
abstract = {The effects of the interaction of a spanwise array of inclined circular synthetic jets with a turbulent channel flow have been experimentally studied. The array is arranged in a convergent couple configuration, where each single jet is oriented at ±45◦ in the plane perpendicular to the mean channel flow. The actuator system is derived from a commercial engine for airplane models where the oscillating piston gives rise to the periodic blowing and suction phases needed for the generation of a synthetic jet. The interaction produces couples of counter-rotating large-scale longitudinal vortical structures organized periodically in the spanwise direction. These vortices persist along the channel up to long distances from the injection section and produce an attenuation of the wall turbulence. Reductions in the mean skin friction of up to 15% and in the turbulence fluctuations (wall shear stress and streamwise velocity) of up to 12% are obtained. The efficiency of the interaction depends on the piston oscillation frequency. The near-wall activity is influenced to a great extent by the action of the large-scale vortices. The variable interval time averaging (VITA) events are reduced and the integral time macroscales are increased while the probability density function (PDF) analysis shows higher levels of intermittency. The interpretation of these effects is given in terms of regeneration mechanisms of the near-wall structures. A comparison between the present control scheme and the forcing obtained using continuous jets has also been made. In the case of synthetic jets, the forcing effects appear weaker with respect to those obtained using continuous jets, at least for the tested conditions. Drag reduction and turbulence attenuation are in fact lower when synthetic jets are used as a forcing technique.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
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}
The effects of the interaction of a spanwise array of inclined circular synthetic jets with a turbulent channel flow have been experimentally studied. The array is arranged in a convergent couple configuration, where each single jet is oriented at ±45◦ in the plane perpendicular to the mean channel flow. The actuator system is derived from a commercial engine for airplane models where the oscillating piston gives rise to the periodic blowing and suction phases needed for the generation of a synthetic jet. The interaction produces couples of counter-rotating large-scale longitudinal vortical structures organized periodically in the spanwise direction. These vortices persist along the channel up to long distances from the injection section and produce an attenuation of the wall turbulence. Reductions in the mean skin friction of up to 15% and in the turbulence fluctuations (wall shear stress and streamwise velocity) of up to 12% are obtained. The efficiency of the interaction depends on the piston oscillation frequency. The near-wall activity is influenced to a great extent by the action of the large-scale vortices. The variable interval time averaging (VITA) events are reduced and the integral time macroscales are increased while the probability density function (PDF) analysis shows higher levels of intermittency. The interpretation of these effects is given in terms of regeneration mechanisms of the near-wall structures. A comparison between the present control scheme and the forcing obtained using continuous jets has also been made. In the case of synthetic jets, the forcing effects appear weaker with respect to those obtained using continuous jets, at least for the tested conditions. Drag reduction and turbulence attenuation are in fact lower when synthetic jets are used as a forcing technique.
2006
M., ONORATO; Maria, DI CICCA Gaetano; Gaetano, IUSO; G., SPAZZINI P.; R., MALVANO
Turbulent Boundary Layers and Their Control: Quantitative Flow Visualization Results Proceedings Article
In: Transition and Turbulence Control, pp. 247-282, World Scientific, 2006, ISBN: 9812564705, (Contributo in Atti di convegno).
@inproceedings{inproceedings_27,
title = {Turbulent Boundary Layers and Their Control: Quantitative Flow Visualization Results},
author = {ONORATO M. and DI CICCA Gaetano Maria and IUSO Gaetano and SPAZZINI P. G. and MALVANO R.},
isbn = {9812564705},
year = {2006},
date = {2006-12-01},
booktitle = {Transition and Turbulence Control},
volume = {Lecture Notes Series ; 8},
pages = {247-282},
publisher = {World Scientific},
abstract = {Results obtained by applying PIV to canonical turbulent boundary layers and to wall flows under the action of external forcing produced by spanwise wall oscillations are shown and analyzed. In particular, results obtained at the Aerodynamic Laboratory of the Politecnico di Torino are discussed, with reference, where it is possible, to results produced in other laboratories. For both flows, PIV images in planes streamwise-normal and parallel to the wall are analyzed.},
note = {Contributo in Atti di convegno},
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Results obtained by applying PIV to canonical turbulent boundary layers and to wall flows under the action of external forcing produced by spanwise wall oscillations are shown and analyzed. In particular, results obtained at the Aerodynamic Laboratory of the Politecnico di Torino are discussed, with reference, where it is possible, to results produced in other laboratories. For both flows, PIV images in planes streamwise-normal and parallel to the wall are analyzed.
Gaetano, IUSO; Erasmo, CARRERA; G, GISMONDI A.; Maria, DI CICCA Gaetano
An attempt of using synthetic jets for aeroelastic control of a simplified smart wing Proceedings Article
In: Titolo volume non avvalorato, 2006, (Contributo in Atti di convegno).
@inproceedings{inproceedingsy,
title = {An attempt of using synthetic jets for aeroelastic control of a simplified smart wing},
author = {IUSO Gaetano and CARRERA Erasmo and GISMONDI A. G and DI CICCA Gaetano Maria},
year = {2006},
date = {2006-07-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
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Maria, DI CICCA Gaetano; Gaetano, IUSO
On Large – Scale Vortical Structures Produced by a Yawed Synthetic Jet – Turbulent Boundary Layer Interaction Proceedings Article
In: Titolo volume non avvalorato, 2006, ISBN: 9781563478130, (Contributo in Atti di convegno).
@inproceedings{inproceedingsz,
title = {On Large - Scale Vortical Structures Produced by a Yawed Synthetic Jet – Turbulent Boundary Layer Interaction},
author = {DI CICCA Gaetano Maria and IUSO Gaetano},
isbn = {9781563478130},
year = {2006},
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Maria, DI CICCA Gaetano; Gaetano, IUSO; DONELLI, R. S.; GREGORIO, F. DE
Turbulent Boundary Layer – Synthetic Jet Interaction: Orifice Orientation Effects Proceedings Article
In: Titolo volume non avvalorato, 2006, (Contributo in Atti di convegno).
@inproceedings{inproceedings_28,
title = {Turbulent Boundary Layer - Synthetic Jet Interaction: Orifice Orientation Effects},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and R. S. DONELLI and F. DE GREGORIO},
year = {2006},
date = {2006-04-01},
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Maria, DI CICCA Gaetano; Gaetano, IUSO; DONELLI, R. S.; GREGORIO, F. DE
Turbulent boundary layer-synthetic jet interaction: orifice orientation effects Proceedings Article
In: Titolo volume non avvalorato, 2006, (Abstract in Atti di convegno).
@inproceedings{inproceedings_29,
title = {Turbulent boundary layer-synthetic jet interaction: orifice orientation effects},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and R. S. DONELLI and F. DE GREGORIO},
year = {2006},
date = {2006-04-01},
booktitle = {Titolo volume non avvalorato},
note = {Abstract in Atti di convegno},
keywords = {},
pubstate = {published},
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Gaetano, IUSO; MARCO, CANNATA; Maria, DI CICCA Gaetano
Spanwise wall-flow oscillations generated by synthetic jets Proceedings Article
In: Titolo volume non avvalorato, 2006, (Abstract in Atti di convegno).
@inproceedings{inproceedings_30,
title = {Spanwise wall-flow oscillations generated by synthetic jets},
author = {IUSO Gaetano and CANNATA MARCO and DI CICCA Gaetano Maria},
year = {2006},
date = {2006-04-01},
booktitle = {Titolo volume non avvalorato},
note = {Abstract in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
IUSO, G; CARRERA, E.; G, GISMONDI A; M, DI CICCA G
An attempt of using synthetic jets for aeroelastic control of a simplified smart wing Conference
Titolo volume non avvalorato, 2006.
@conference{ 11583_1497714,
title = {An attempt of using synthetic jets for aeroelastic control of a simplified smart wing},
author = {G IUSO and E. CARRERA and GISMONDI A G and DI CICCA G M},
year = {2006},
date = {2006-01-01},
booktitle = {Titolo volume non avvalorato},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
2005
Maria, DI CICCA Gaetano; Gaetano, IUSO
On a Yawed Synthetic Jet – Turbulent Boundary Layer Interaction Proceedings Article
In: Titolo volume non avvalorato, pp. 1-17, 2005, (Contributo in Atti di convegno).
@inproceedings{inproceedings_34,
title = {On a Yawed Synthetic Jet – Turbulent Boundary Layer Interaction},
author = {DI CICCA Gaetano Maria and IUSO Gaetano},
year = {2005},
date = {2005-09-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-17},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gaetano, IUSO; M., ONORATO
Progetto PRO. R.A. UAV – C.I.R.A. Active flow control using synthetic jets Miscellaneous
2005, (Altro).
@misc{miscj,
title = {Progetto PRO. R.A. UAV - C.I.R.A. Active flow control using synthetic jets},
author = {IUSO Gaetano and ONORATO M.},
year = {2005},
date = {2005-01-01},
abstract = {Report Tecnico su Contratto di ricerca CIRA-DIASP},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Report Tecnico su Contratto di ricerca CIRA-DIASP
2004
Gaetano, IUSO; R., Malvano; ALINE, PICCATO; GIORGIO, SPAZZINI PIER; Maria, DI CICCA Gaetano; Michele, ONORATO
Wall measurements in a cavity flow Proceedings Article
In: Titolo volume non avvalorato, pp. 1-5, 2004, ISBN: 0953399168, (Contributo in Atti di convegno).
@inproceedings{inproceedings_35,
title = {Wall measurements in a cavity flow},
author = {IUSO Gaetano and Malvano R. and PICCATO ALINE and SPAZZINI PIER GIORGIO and DI CICCA Gaetano Maria and ONORATO Michele},
isbn = {0953399168},
year = {2004},
date = {2004-08-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-5},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
SPAZZINI, P. G.; PICCATO, A.; Gaetano, IUSO; Maria, DI CICCA Gaetano; MALVANO, R.; Michele, ONORATO
Visualization of Vortical Structures within an Elongated Cavity Proceedings Article
In: Titolo volume non avvalorato, 2004, (Contributo in Atti di convegno).
@inproceedings{inproceedings_37,
title = {Visualization of Vortical Structures within an Elongated Cavity},
author = {P. G. SPAZZINI and A. PICCATO and IUSO Gaetano and DI CICCA Gaetano Maria and R. MALVANO and ONORATO Michele},
year = {2004},
date = {2004-08-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Maria, DI CICCA Gaetano; Gaetano, IUSO; GIORGIO, SPAZZINI PIER; R., MALVANO; Michele, ONORATO
Near Field Study of a Synthetic Jet Proceedings Article
In: Titolo volume non avvalorato, pp. 1-7, 2004, ISBN: 0953399168, (Contributo in Atti di convegno).
@inproceedings{inproceedings_38,
title = {Near Field Study of a Synthetic Jet},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and SPAZZINI PIER GIORGIO and MALVANO R. and ONORATO Michele},
isbn = {0953399168},
year = {2004},
date = {2004-08-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-7},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gaetano, IUSO; Maria, DI CICCA Gaetano; G, SPAZZINI P.; M., ONORATO
Synthetic jets interaction with a fully turbulent channel flow Proceedings Article
In: Titolo volume non avvalorato, 2004, (Abstract in Atti di convegno).
@inproceedings{inproceedings_36,
title = {Synthetic jets interaction with a fully turbulent channel flow},
author = {IUSO Gaetano and DI CICCA Gaetano Maria and SPAZZINI P. G and ONORATO M.},
year = {2004},
date = {2004-06-01},
booktitle = {Titolo volume non avvalorato},
note = {Abstract in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
JACOB, B.; BIFERALE, L.; IUSO, G.; CASCIOLA, C. M.
Anisotropic fluctuations in turbulent shear flows Journal Article
In: PHYSICS OF FLUIDS, vol. 16, pp. 4135–4142, 2004.
@article{ 11583_1405648,
title = {Anisotropic fluctuations in turbulent shear flows},
author = {B. JACOB and L. BIFERALE and G. IUSO and C. M. CASCIOLA},
doi = {10.1063/1.1789546},
year = {2004},
date = {2004-01-01},
journal = {PHYSICS OF FLUIDS},
volume = {16},
pages = {4135--4142},
publisher = {AIP},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gaetano, IUSO; M., ONORATO
Progetto PRO. R.A. UAV-C.I.R.A. Active flow control using synthetic jets Miscellaneous
2004, (Altro).
@misc{misck,
title = {Progetto PRO. R.A. UAV-C.I.R.A. Active flow control using synthetic jets},
author = {IUSO Gaetano and ONORATO M.},
year = {2004},
date = {2004-01-01},
abstract = {Report Tecnico su Contratto di ricerca CIRA-DIASP},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Report Tecnico su Contratto di ricerca CIRA-DIASP
Gaetano, IUSO; Maria, DI CICCA Gaetano; GIORGIO, SPAZZINI PIER; R., MALVANO; M., AUDINO F.; Michele, ONORATO
Flat Plate Turbulent Boundary Layer Under the Action of as Periodic Forcing Proceedings Article
In: Titolo volume non avvalorato, pp. 1-11, 2004, ISBN: 095339915X, (Contributo in Atti di convegno).
@inproceedings{inproceedings_39,
title = {Flat Plate Turbulent Boundary Layer Under the Action of as Periodic Forcing},
author = {IUSO Gaetano and DI CICCA Gaetano Maria and SPAZZINI PIER GIORGIO and MALVANO R. and AUDINO F. M. and ONORATO Michele},
isbn = {095339915X},
year = {2004},
date = {2004-01-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-11},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
B., JACOB; L., BIFERALE; Gaetano, IUSO; M., CASCIOLA C.
Anisotropic fluctuations in turbulent shear flows Journal Article
In: PHYSICS OF FLUIDS, vol. 16, pp. 4135-4142, 2004, ISSN: 1070-6631, (Articolo in rivista).
@article{articlen,
title = {Anisotropic fluctuations in turbulent shear flows},
author = {JACOB B. and BIFERALE L. and IUSO Gaetano and CASCIOLA C. M.},
doi = {10.1063/1.1789546},
issn = {1070-6631},
year = {2004},
date = {2004-01-01},
journal = {PHYSICS OF FLUIDS},
volume = {16},
pages = {4135-4142},
abstract = {An experimental analysis of small-scale anisotropic fluctuations has been performed in two different flows in order to assess possible universal features of shear dominated turbulence, such as the decay rate of anisotropy at small scales and the recovery of isotropy. The two data sets—a homogeneous shear flow and a turbulent boundary layer—are characterized by turbulent Reynolds numbers in the range Re_lambda=230−330. The measurements in the logarithmic region of the turbulent boundary layer extend from y+=90 up to y+=350. The explicit use of the Taylor hypothesis is avoided by resorting to two-point measurements, with separation in the spanwise direction, z. Streamwise (u) and wall-normal (v) velocity components are simultaneously measured in both positions by means of cross-wire probes. This procedure allows the construction of the mixed transverse structure functions, here addressed up to order 6. According to the SO(3) formalism, the observables we selected are free of any isotropic contribution, thus allowing a direct measurement of the fully anisotropic component of the field. The results are consistent with the “exponent-only” scenario for universality, i.e., all experimental data can be fitted by fixing the same set of anisotropic scaling exponents by changing only the prefactors, for different shear intensities and boundary conditions.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An experimental analysis of small-scale anisotropic fluctuations has been performed in two different flows in order to assess possible universal features of shear dominated turbulence, such as the decay rate of anisotropy at small scales and the recovery of isotropy. The two data sets—a homogeneous shear flow and a turbulent boundary layer—are characterized by turbulent Reynolds numbers in the range Re_lambda=230−330. The measurements in the logarithmic region of the turbulent boundary layer extend from y+=90 up to y+=350. The explicit use of the Taylor hypothesis is avoided by resorting to two-point measurements, with separation in the spanwise direction, z. Streamwise (u) and wall-normal (v) velocity components are simultaneously measured in both positions by means of cross-wire probes. This procedure allows the construction of the mixed transverse structure functions, here addressed up to order 6. According to the SO(3) formalism, the observables we selected are free of any isotropic contribution, thus allowing a direct measurement of the fully anisotropic component of the field. The results are consistent with the “exponent-only” scenario for universality, i.e., all experimental data can be fitted by fixing the same set of anisotropic scaling exponents by changing only the prefactors, for different shear intensities and boundary conditions.
2003
Maria, DI CICCA Gaetano; Gaetano, IUSO; VIVIANO, A.; Michele, ONORATO; GIORGIO, SPAZZINI PIER; MALVANO, R.
PIV Study of Synthetic Jets Proceedings Article
In: Titolo volume non avvalorato, pp. 1-11, 2003, ISBN: 0953399141, (Contributo in Atti di convegno).
@inproceedings{inproceedings_45,
title = {PIV Study of Synthetic Jets},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and A. VIVIANO and ONORATO Michele and SPAZZINI PIER GIORGIO and R. MALVANO},
isbn = {0953399141},
year = {2003},
date = {2003-08-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-11},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Maria, DI CICCA Gaetano; GIORGIO, SPAZZINI PIER; Gaetano, IUSO; MALVANO, R.; POLLEDRO, P.; Michele, ONORATO
PIV investigation on a controlled backward facing step flow Proceedings Article
In: Titolo volume non avvalorato, pp. 10, 2003, (Contributo in Atti di convegno).
@inproceedings{inproceedings_43,
title = {PIV investigation on a controlled backward facing step flow},
author = {DI CICCA Gaetano Maria and SPAZZINI PIER GIORGIO and IUSO Gaetano and R. MALVANO and P. POLLEDRO and ONORATO Michele},
year = {2003},
date = {2003-06-01},
booktitle = {Titolo volume non avvalorato},
pages = {10},
abstract = {Digital particle image velocimetry technique has been applied to the study of a passive control method for separated flows downstream a backward facing step (BFS). The method consists in substituting the solid wall downstream the step, in the separated region, by a permeable surface under which lays a sealed plenum. An almost complete damping of the low frequency fluctuation typical of the BFS flows including detected spanwise oscillations has been observed. The measurement technique allowed to provide an explanation for the controlled flow behavior.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Digital particle image velocimetry technique has been applied to the study of a passive control method for separated flows downstream a backward facing step (BFS). The method consists in substituting the solid wall downstream the step, in the separated region, by a permeable surface under which lays a sealed plenum. An almost complete damping of the low frequency fluctuation typical of the BFS flows including detected spanwise oscillations has been observed. The measurement technique allowed to provide an explanation for the controlled flow behavior.
CHIOCCHIA, G.; IUSO, G.; CARRERA, E.; FREDIANI, A.
A wind tunnel model of a ULM configuration of Prandtplane: design, manufacturing and aerodynamic testing Conference
Titolo volume non avvalorato, 2003.
@conference{ 11583_1408611,
title = {A wind tunnel model of a ULM configuration of Prandtplane: design, manufacturing and aerodynamic testing},
author = {G. CHIOCCHIA and G. IUSO and E. CARRERA and A. FREDIANI},
year = {2003},
date = {2003-01-01},
booktitle = {Titolo volume non avvalorato},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
ONORATO, M; IUSO, G.; DAMBROSIO, D
Aerodinamica dei caschi da motociclista: studio sperimentale e numerico Miscellaneous
2003.
@misc{ 11583_1678332,
title = {Aerodinamica dei caschi da motociclista: studio sperimentale e numerico},
author = {M ONORATO and G. IUSO and D DAMBROSIO},
year = {2003},
date = {2003-01-01},
abstract = {Report Tecnico su Contratto di ricerca AGV-DIASP},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Report Tecnico su Contratto di ricerca AGV-DIASP
IUSO, G.; ONORATO, M.; D’AMBROSIO, D.
Aerodinamica dei caschi da motociclista: studio sperimentale e numerico Miscellaneous
2003.
@misc{ 11583_2424766,
title = {Aerodinamica dei caschi da motociclista: studio sperimentale e numerico},
author = {G. IUSO and M. ONORATO and D. D’AMBROSIO},
year = {2003},
date = {2003-01-01},
abstract = {Indagine sperimentale e numerica sulla valutazione delle caratteristiche aerodinamiche dei caschi da motociclista.},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Indagine sperimentale e numerica sulla valutazione delle caratteristiche aerodinamiche dei caschi da motociclista.
IUSO, G.; M, DI CICCA G.; SPAZZINI, P. G.; MALVANO, R.; ONORATO, M.
Caratterizzazione del campo di moto di un getto sintetico Conference
Titolo volume non avvalorato, 2003.
@conference{ 11583_1415136,
title = {Caratterizzazione del campo di moto di un getto sintetico},
author = {G. IUSO and DI CICCA G. M and P. G. SPAZZINI and R. MALVANO and M. ONORATO},
year = {2003},
date = {2003-01-01},
booktitle = {Titolo volume non avvalorato},
pages = {1--7},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Gaetano, IUSO; Maria, DI CICCA Gaetano; Michele, ONORATO; GIORGIO, SPAZZINI PIER; R., MALVANO
Velocity streak structure modifications induced by flow manipulation Journal Article
In: PHYSICS OF FLUIDS, vol. 15, pp. 2602-2612, 2003, ISSN: 1070-6631, (Articolo in rivista).
@article{articleo,
title = {Velocity streak structure modifications induced by flow manipulation},
author = {IUSO Gaetano and DI CICCA Gaetano Maria and ONORATO Michele and SPAZZINI PIER GIORGIO and MALVANO R.},
doi = {10.1063/1.1597680},
issn = {1070-6631},
year = {2003},
date = {2003-01-01},
journal = {PHYSICS OF FLUIDS},
volume = {15},
pages = {2602-2612},
abstract = {The present research is based on the belief that the observation of the response of near wall turbulent organized motions to external perturbations is a powerful technique for investigating the physics of turbulence regeneration. The low speed streak behavior in the buffer layer of a flat plate turbulent boundary layer under the action of transversal wall oscillation has been statistically analyzed by observing particle image velocimetry velocity fields in a plane parallel to the wall at a distance of 20 wall units. It was found that the observed reduction in turbulence activity (velocity variance and Reynolds stress) is accompanied by an increase of the averaged velocity streaks width, spacing and waviness and by a reduction of their strength. The increase in streak width and spacing has been attributed mainly to coalescence processes between neighboring streaks. The occurrence of velocity streaks strength reduction, associated with the consequent decrease of the number of unstable low speed streaks, is believed to be the main reason leading to the reduction of turbulent activity. The interpretation of the present results supports the concept that the so-called streak regeneration cycle plays an important role in the near wall turbulence reproduction process.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The present research is based on the belief that the observation of the response of near wall turbulent organized motions to external perturbations is a powerful technique for investigating the physics of turbulence regeneration. The low speed streak behavior in the buffer layer of a flat plate turbulent boundary layer under the action of transversal wall oscillation has been statistically analyzed by observing particle image velocimetry velocity fields in a plane parallel to the wall at a distance of 20 wall units. It was found that the observed reduction in turbulence activity (velocity variance and Reynolds stress) is accompanied by an increase of the averaged velocity streaks width, spacing and waviness and by a reduction of their strength. The increase in streak width and spacing has been attributed mainly to coalescence processes between neighboring streaks. The occurrence of velocity streaks strength reduction, associated with the consequent decrease of the number of unstable low speed streaks, is believed to be the main reason leading to the reduction of turbulent activity. The interpretation of the present results supports the concept that the so-called streak regeneration cycle plays an important role in the near wall turbulence reproduction process.
Gaetano, IUSO; Michele, ONORATO; Domenic, D’AMBROSIO
Aerodinamica dei caschi da motociclista: studio sperimentale e numerico Miscellaneous
2003, (Altro).
@misc{miscl,
title = {Aerodinamica dei caschi da motociclista: studio sperimentale e numerico},
author = {IUSO Gaetano and ONORATO Michele and D'AMBROSIO Domenic},
year = {2003},
date = {2003-01-01},
pages = {50},
abstract = {Indagine sperimentale e numerica sulla valutazione delle caratteristiche aerodinamiche dei caschi da motociclista.},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Indagine sperimentale e numerica sulla valutazione delle caratteristiche aerodinamiche dei caschi da motociclista.
M, ONORATO; Gaetano, IUSO; Domenic, D’AMBROSIO
Aerodinamica dei caschi da motociclista: studio sperimentale e numerico Miscellaneous
2003, (Altro).
@misc{miscm,
title = {Aerodinamica dei caschi da motociclista: studio sperimentale e numerico},
author = {ONORATO M and IUSO Gaetano and D'AMBROSIO Domenic},
year = {2003},
date = {2003-01-01},
abstract = {Report Tecnico su Contratto di ricerca AGV-DIASP},
note = {Altro},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Report Tecnico su Contratto di ricerca AGV-DIASP
Maria, DI CICCA Gaetano; Gaetano, IUSO; G., SPAZZINI P.; R., MALVANO; Michele, ONORATO
On the physics of near wall turbulence PIV studies Proceedings Article
In: Titolo volume non avvalorato, 2003, (Contributo in Atti di convegno).
@inproceedings{inproceedings_41,
title = {On the physics of near wall turbulence PIV studies},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and SPAZZINI P. G. and MALVANO R. and ONORATO Michele},
year = {2003},
date = {2003-01-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gianfranco, CHIOCCHIA; Gaetano, IUSO; Erasmo, CARRERA; A., FREDIANI
A wind tunnel model of a ULM configuration of Prandtplane: design, manufacturing and aerodynamic testing Proceedings Article
In: Titolo volume non avvalorato, 2003, (Contributo in Atti di convegno).
@inproceedings{inproceedings_44,
title = {A wind tunnel model of a ULM configuration of Prandtplane: design, manufacturing and aerodynamic testing},
author = {CHIOCCHIA Gianfranco and IUSO Gaetano and CARRERA Erasmo and FREDIANI A.},
year = {2003},
date = {2003-01-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
2001
A, SHAH D.; T, BALENDRA; A, COSTANTINI; P, MORELLI; Gaetano, IUSO
Interference effects between tall buildings in a simulated atmospheric boundary layer Proceedings Article
In: Titolo volume non avvalorato, 2001, (Contributo in Atti di convegno).
@inproceedings{inproceedings_50,
title = {Interference effects between tall buildings in a simulated atmospheric boundary layer},
author = {SHAH D. A and BALENDRA T and COSTANTINI A and MORELLI P and IUSO Gaetano},
year = {2001},
date = {2001-10-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Maria, DI CICCA Gaetano; Gaetano, IUSO; GIORGIO, SPAZZINI PIER; Michele, ONORATO
PIV Studies of a Turbulent Boundary Layer Subject to External Perturbations Proceedings Article
In: Titolo volume non avvalorato, pp. 1-7, 2001, (Contributo in Atti di convegno).
@inproceedings{inproceedings_52,
title = {PIV Studies of a Turbulent Boundary Layer Subject to External Perturbations},
author = {DI CICCA Gaetano Maria and IUSO Gaetano and SPAZZINI PIER GIORGIO and ONORATO Michele},
year = {2001},
date = {2001-09-01},
booktitle = {Titolo volume non avvalorato},
pages = {1-7},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Cicca, Gaetano Maria Di; Onorato, Michele; Iuso, Gaetano; Spazzini, P. G.
Application of Particle Image Velocimetry to Wall Turbulence Studies Journal Article
In: ATTI DELLA ACCADEMIA DELLE SCIENZE DI TORINO. CLASSE DI SCIENZE FISICHE MATEMATICHE E NATURALI, vol. 135, pp. 43–65, 2001.
@article{ 11583_1645244,
title = {Application of Particle Image Velocimetry to Wall Turbulence Studies},
author = {Gaetano Maria Di Cicca and Michele Onorato and Gaetano Iuso and P. G. Spazzini},
year = {2001},
date = {2001-01-01},
journal = {ATTI DELLA ACCADEMIA DELLE SCIENZE DI TORINO. CLASSE DI SCIENZE FISICHE MATEMATICHE E NATURALI},
volume = {135},
pages = {43--65},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
GIORGIO, SPAZZINI PIER; Gaetano, IUSO; Michele, ONORATO; Nicola, ZURLO; Maria, DI CICCA Gaetano
Unsteady behavior of back-facing step flow Journal Article
In: EXPERIMENTS IN FLUIDS, vol. 30, pp. 551-561, 2001, ISSN: 0723-4864, (Articolo in rivista).
@article{articlet,
title = {Unsteady behavior of back-facing step flow},
author = {SPAZZINI PIER GIORGIO and IUSO Gaetano and ONORATO Michele and ZURLO Nicola and DI CICCA Gaetano Maria},
doi = {10.1007/s003480000234},
issn = {0723-4864},
year = {2001},
date = {2001-01-01},
journal = {EXPERIMENTS IN FLUIDS},
volume = {30},
pages = {551-561},
abstract = {In this paper, a contribution to the study of the unsteady behavior of a back facing step flow is reported. The main interest is devoted to low-frequency motions. A probe for skin friction measurements is employed to acquire time hystories from the step to downstream the the reattachment region. Signals are analyzed in the physical space and in the frequency domain. The obtained results, associated with flow visualization in a companion experiment in water, support a model of cyclic motion of growing and successive breakdown of the secondary recirculating bubble. The frequency of this quasi-periodic motion is comparable to the flapping frequency of the whole separated regio, reported in the literature.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, a contribution to the study of the unsteady behavior of a back facing step flow is reported. The main interest is devoted to low-frequency motions. A probe for skin friction measurements is employed to acquire time hystories from the step to downstream the the reattachment region. Signals are analyzed in the physical space and in the frequency domain. The obtained results, associated with flow visualization in a companion experiment in water, support a model of cyclic motion of growing and successive breakdown of the secondary recirculating bubble. The frequency of this quasi-periodic motion is comparable to the flapping frequency of the whole separated regio, reported in the literature.
Maria, DI CICCA Gaetano; Michele, ONORATO; Gaetano, IUSO; SPAZZINI, P. G.
Application of Particle Image Velocimetry to Wall Turbulence Studies Journal Article
In: ATTI DELLA ACCADEMIA DELLE SCIENZE DI TORINO. CLASSE DI SCIENZE FISICHE MATEMATICHE E NATURALI, vol. 135, pp. 43-65, 2001, ISSN: 0001-4419, (Articolo in rivista).
@article{articleu,
title = {Application of Particle Image Velocimetry to Wall Turbulence Studies},
author = {DI CICCA Gaetano Maria and ONORATO Michele and IUSO Gaetano and P. G. SPAZZINI},
issn = {0001-4419},
year = {2001},
date = {2001-01-01},
journal = {ATTI DELLA ACCADEMIA DELLE SCIENZE DI TORINO. CLASSE DI SCIENZE FISICHE MATEMATICHE E NATURALI},
volume = {135},
pages = {43-65},
abstract = {Particle Image Velocimetry has been applied to the study of organized motions in the turbulent boundary layer over a flat plate, in absence of pressure gradients. Flow observations were conducted both in planes parallel to the wall (within the buffer layer) and in streamwise planes normal to the wall. Trains of "quasi-longitudinal vortices" (some of which highly inclined with respect to the wall) and packets of non-symmetric hairpin structures are postulated to co-exist in order to explain the detected swirling motions in both planes. Organized motions (low speed streaks, vortical structures) have been carefully analyzed together with their manifestations (VITA events, Q2 and Q4 motions); special attention is paid to the observation of the spatial relationships between these different phenomena.},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Particle Image Velocimetry has been applied to the study of organized motions in the turbulent boundary layer over a flat plate, in absence of pressure gradients. Flow observations were conducted both in planes parallel to the wall (within the buffer layer) and in streamwise planes normal to the wall. Trains of “quasi-longitudinal vortices” (some of which highly inclined with respect to the wall) and packets of non-symmetric hairpin structures are postulated to co-exist in order to explain the detected swirling motions in both planes. Organized motions (low speed streaks, vortical structures) have been carefully analyzed together with their manifestations (VITA events, Q2 and Q4 motions); special attention is paid to the observation of the spatial relationships between these different phenomena.
MIGUEL, ONORATO; Gaetano, IUSO
Probability density function and “plus” and “minus” structure functions in a turbulent channel flow Journal Article
In: PHYSICAL REVIEW E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS, vol. 63, pp. 025302-1-025302-4, 2001, ISSN: 1539-3755, (Articolo in rivista).
@article{articlev,
title = {Probability density function and "plus" and "minus" structure functions in a turbulent channel flow},
author = {ONORATO MIGUEL and IUSO Gaetano},
doi = {10.1103/PhysRevE.63.025302},
issn = {1539-3755},
year = {2001},
date = {2001-01-01},
journal = {PHYSICAL REVIEW E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS},
volume = {63},
pages = {025302-1-025302-4},
note = {Articolo in rivista},
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pubstate = {published},
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2000
GIORGIO, SPAZZINI PIER; Gaetano, IUSO; ZURLO, N.; Maria, DI CICCA Gaetano; Michele, ONORATO
Flow control downstream of a backward facing step Proceedings Article
In: Titolo volume non avvalorato, pp. 10, 2000, (Contributo in Atti di convegno).
@inproceedings{inproceedings_54,
title = {Flow control downstream of a backward facing step},
author = {SPAZZINI PIER GIORGIO and IUSO Gaetano and N. ZURLO and DI CICCA Gaetano Maria and ONORATO Michele},
year = {2000},
date = {2000-08-01},
booktitle = {Titolo volume non avvalorato},
pages = {10},
abstract = {A simple LEBU-like device aimed at controlling the separated flow field behind a backward facing step, with special attention on its unsteady properties, is described; the device advantage is that it requires very small design modifications and/or complications. Visualizations of the controlled field are presented along with wall hot-wire measurements. The latter measurements provided information about both the mean wall quantities (skin friction) and unsteady properties (wall shear
stress fluctuations); RMS and spectra of these fluctuations are presented, showing how the distribution of fluctuation energy is influenced by the presence of the manipulator. In particular,
specific positionings of the device allowed to reduce wall unsteadinesses. To summarize the outcomes of the work, although the research is in its early stages, the results presented here prove the viability of this way of controlling separated flows.},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
A simple LEBU-like device aimed at controlling the separated flow field behind a backward facing step, with special attention on its unsteady properties, is described; the device advantage is that it requires very small design modifications and/or complications. Visualizations of the controlled field are presented along with wall hot-wire measurements. The latter measurements provided information about both the mean wall quantities (skin friction) and unsteady properties (wall shear
stress fluctuations); RMS and spectra of these fluctuations are presented, showing how the distribution of fluctuation energy is influenced by the presence of the manipulator. In particular,
specific positionings of the device allowed to reduce wall unsteadinesses. To summarize the outcomes of the work, although the research is in its early stages, the results presented here prove the viability of this way of controlling separated flows.
stress fluctuations); RMS and spectra of these fluctuations are presented, showing how the distribution of fluctuation energy is influenced by the presence of the manipulator. In particular,
specific positionings of the device allowed to reduce wall unsteadinesses. To summarize the outcomes of the work, although the research is in its early stages, the results presented here prove the viability of this way of controlling separated flows.
Maria, DI CICCA Gaetano; Michele, ONORATO; Gaetano, IUSO; G., SPAZZINI P.
Quantitative flow visualization of a manipulated turbulent boundary layer flow Proceedings Article
In: Titolo volume non avvalorato, 2000, (Contributo in Atti di convegno).
@inproceedings{inproceedings_56,
title = {Quantitative flow visualization of a manipulated turbulent boundary layer flow},
author = {DI CICCA Gaetano Maria and ONORATO Michele and IUSO Gaetano and SPAZZINI P. G.},
year = {2000},
date = {2000-08-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
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Maria, DI CICCA Gaetano; Michele, ONORATO; Gaetano, IUSO; G., SPAZZINI P.
Turbulent boundary layer manipulation by longitudinal embedded vortices Proceedings Article
In: Titolo volume non avvalorato, 2000, (Contributo in Atti di convegno).
@inproceedings{inproceedings_57,
title = {Turbulent boundary layer manipulation by longitudinal embedded vortices},
author = {DI CICCA Gaetano Maria and ONORATO Michele and IUSO Gaetano and SPAZZINI P. G.},
year = {2000},
date = {2000-07-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Michele, ONORATO; Maria, DI CICCA Gaetano; Gaetano, IUSO; SPAZZINI, P. G.
DPIV Studies of Turbulent Boundary Layers Proceedings Article
In: Advances in Turbulence VIII, pp. 345-348, CIMNE (International Center for Numerical Methods in Engineering), Barcellona (E) – ESP, 2000, ISBN: 8489925658, (Contributo in Atti di convegno).
@inproceedings{inproceedings_53,
title = {DPIV Studies of Turbulent Boundary Layers},
author = {ONORATO Michele and DI CICCA Gaetano Maria and IUSO Gaetano and P. G. SPAZZINI},
isbn = {8489925658},
year = {2000},
date = {2000-06-01},
booktitle = {Advances in Turbulence VIII},
pages = {345-348},
publisher = {CIMNE (International Center for Numerical Methods in Engineering)},
address = {Barcellona (E) - ESP},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gaetano, IUSO; J.R., ONORATO M.
Asymmetry of velocity increments in a turbulent channel flow Proceedings Article
In: Titolo volume non avvalorato, 2000, (Contributo in Atti di convegno).
@inproceedings{inproceedings_55,
title = {Asymmetry of velocity increments in a turbulent channel flow},
author = {IUSO Gaetano and ONORATO M. J.R.},
year = {2000},
date = {2000-06-01},
booktitle = {Titolo volume non avvalorato},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Michele, ONORATO; Gaetano, IUSO; Maria, DI CICCA Gaetano; GIORGIO, SPAZZINI PIER
Turbulence control in near wall flow Proceedings Article
In: Titolo volume non avvalorato, pp. 1-12, 2000, (Contributo in Atti di convegno).
@inproceedings{inproceedings_58,
title = {Turbulence control in near wall flow},
author = {ONORATO Michele and IUSO Gaetano and DI CICCA Gaetano Maria and SPAZZINI PIER GIORGIO},
year = {2000},
date = {2000-06-01},
booktitle = {Titolo volume non avvalorato},
volume = {AIAA-2000-2659},
pages = {1-12},
note = {Contributo in Atti di convegno},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
IUSO, G.; ONORATO, M. JR.
Asymmetry of velocity increments in a turbulent channel flow Conference
Titolo volume non avvalorato, 2000.
@conference{ 11583_1417525,
title = {Asymmetry of velocity increments in a turbulent channel flow},
author = {G. IUSO and M. JR. ONORATO},
year = {2000},
date = {2000-01-01},
booktitle = {Titolo volume non avvalorato},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
JR, ONORATO M.; R, CAMUSSI; Gaetano, IUSO
Small scale intermittency and bursting in a turbulent channel flow Journal Article
In: PHYSICAL REVIEW E, vol. 61, n.2, pp. 1447-1454, 2000, ISSN: 1063-651X, (Articolo in rivista).
@article{articlew,
title = {Small scale intermittency and bursting in a turbulent channel flow},
author = {ONORATO M. JR and CAMUSSI R and IUSO Gaetano},
issn = {1063-651X},
year = {2000},
date = {2000-01-01},
journal = {PHYSICAL REVIEW E},
volume = {61, n.2},
pages = {1447-1454},
note = {Articolo in rivista},
keywords = {},
pubstate = {published},
tppubtype = {article}
}