Plasma control of vortex flow on a delta wing at high angles of attack

The flow over a delta wing at high angles of attack is characterized by the presence of two large-scale primary vortices on the leeward side of the wing. These vortices contribute substantially to lift production at high angles of attack. Therefore, vortex breakdown, which can be induced by unfavorable pressure gradients or free-stream disturbances, can lead to an abrupt decrease in lift and to the emergence of a roll moment. Thus, the possibility of vortex flow control can be very useful. The problem of vortex flow control is investigated experimentally under subsonic flow parameters in the range of wing chord-based Reynolds number (0.14, 0.25) × 106. A dielectric barrier discharge (DBD) is used as an active control actuator. The data obtained by means of oil flow and smoke flow visualization, surface pressure measurements, and using a particle image velocimetry technique show that the DBD can provoke early vortex bursting. Under certain conditions (discharge excitation mode and frequency), flow excitation by the discharge actuator is found to result in vortex stabilization.