Flow control of automobile with plasma vortex generator

In this study, a plasma actuator was used to examine the wake flow control of an automobile with the aid of wind tunnel test methods, such as surface pressure measurement and particle image velocimetry (PIV) measurement. The control mechanism and law of the plasma vortex generator in the wake field of an Ahmed model were described. The effects of certain factors were analyzed. Results showed that the streamwise vortex induced by a dielectric-barrier-discharge vortex generator (DBD-VG) could promote the mixing of high-speed airflow above the slanted surface at the end of the model and low-speed airflow near the wall by increasing airflow turbulence, thereby inhibiting the generation of separation bubbles and reducing drag. Drag reduction decreased as the total discharge length of the DBD-VG decreased, but its backward distance had the largest effect on the drag reduction rate, followed by its counter distance. Meanwhile, the shortening of the streamwise length had the least effect on the drag reduction rate. When installing the DBG-VG, the end of the actuator should be arranged near the separation line to enable the generation and development of the streamwise vortex before the separation line to achieve the strongest flow control effect. The DBD-VG need not be arranged precisely at the airflow separation point, which demonstrates its favorable versatility. At low speeds, a maximum drag reduction rate of −8.51 % was obtained at an excitation voltage of 13 kV under the control of the DBD-VG, which demonstrated its strong flow control capability.