Active control of the flow behind a two-dimensional bluff body in ground proximity

Active flow control around a two-dimensional geometry positioned near the ground is experimentally studied. Results for two model configurations are reported: one square-back and the other with a flap added at the rear-corner. The model rear end static pressure and the near-wake flow properties are derived from wall-pressure measurements, high-speed Particle Image Velocimetry acquisitions and hot-wire anemometry. The control flow is obtained from a pulsed jet system driven in open loop. The study aims at distinguishing the individual influence of the passive flap and the control system. The actuation frequency is shown to be a determining parameter regarding rear end pressure increase.