Drag reduction of 3D bluff body using SDBD plasma actuators

In the current research, a series of different combinations of plasma SDBD actuators mounted on a simplified road vehicle have been experimentally studied to find the optimum position of the actuators for controlling the flow separation and reducing the vehicle form drag. Separation point of the flow over the rear ramp, large trailing vortices of the standard model, and laminar separation bubble (LSB) of the rear ramp leading edge are among the most significant factors to be controlled. The experiments were conducted at Reynolds numbers ranging from 0.55 x 10(6) to 1.11 x 10(6) in a subsonic wind tunnel while the pressure distribution over the model and its streamwise force balance were accurately measured. Significant drag reduction due to the use of DBD actuators was observed. As such, for the range of tested Reynolds numbers, a maximum of 25.1% of drag reduction in the vehicle drag coefficient could be achieved. The optimum combinations of activation voltages (6, 9, and 12 kV) and wave frequencies (6, 10, and 14 kHz) for plasma actuators were also found. Furthermore, it was observed that SDBD actuators mounted on the rear ramp of the model had a deeper impact on the vehicle drag coefficient compared to the other actuators.