Swirling jets are among the most common jet topologies present in industrial application thanks to their ability to enhance heat transfer and mixing. A swirling jet (see the azimuthal velocity fields below) can be obtained by adding an azimuthal velocity component to a stream coming out from a circular orifice. They are usually made by means of helicoidal insets installed in the nozzle outlet. Nevertheless, by doing this, the characteristics of the developed flowfield are fixed and cannot be changed without geometrically modifying said insert.
Plasma actuators (PAs) have been considered as flow control devices in jet flows given their versatility of use, their low intrusiveness, and their low power consumption. Preliminary studies aimed at exploring the feasibility of inducing a swirling motion to a circular jet by exploiting the momentum injection of the dielectric barrier discharge plasma actuators (DBD-PAs) wave been carried out. The picture below shows the jet outlet with four tangentially oriented plasma jets (the blueish glow) as seen from downstream.
