Interaction of streamwise vortex pair induced by counter type plasma jet with flow past a circular cylinder

Abstract

A streamwise vortex pair induced by a counter-type plasma actuator interacts with the separated shear layer from a circular cylinder. The spanwise array of the plasma actuator placed on the surface of the circular cylinder works in place of the vortex generator. Induced jets from the adjacent actuators interact with each other and produce streamwise vortex pairs. Flow visualizations in quiescent air and in the wake region of the cylinder were performed using a high speed camera and PIV analysis. The spanwise flow structure in the cylinder wake was investigated through hot-wire measurements. Flow visualization revealed that vortex pairs generated by the counter-type plasma actuator were effectively introduced into the separated shear layer. Hot-wire measurements showed that the interaction between the streamwise vortex pair with the shear layer enhanced the turbulent mixing, improving the velocity defect in the wake.