Study on Highspeed UAV Separation Flow Characteristics by Dielectric Barrier Discharge Plasma

In this paper, a calculation of restraining flow separation of the high-speed UAV airfoil with dielectric barrier discharge (DBD) plasma is studied. Based on the simplified model of the DBD plasma, the effect of plasma on neutral gas is considered as a body force, which is introduced into the Navier-Stokes (N-S) equation as a source term by using the user-defined functions interface in computational fluid dynamics (CFD) software. In this way, the distribution of the flow field of the plasma can be obtained, allowing for the analysis of the mechanism of suppression by the plasma in flow separation. The lift coefficient and the drag coefficient were chosen as two characterizations, then the situations of the plasma actuator in different positions and the airfoil at different angles of attack were quantitatively analyzed. The digital simulation test results indicate that for the high-speed airfoil selected in this paper, when the actuator is at 0.6C (C is the chord length) at the trailing edge in high-speed flight, the effect of the actuator will increase the lift-drag ratio of the high-speed airfoil, and the smaller the angle of attack is, the greater the increment will be, with the maximum increment being about 2.28%.