Burst Frequency Effect of DBD Plasma Actuator on the Control of Separated Flow over an Airfoil

Abstract

The flow fields around NACA0015 airfoil, separation over which is controlled by a DBD plasma actuator are simulated by implicit large eddy simulation with compact difference scheme, and the burst frequency effect of DBD plasma actuator on the control of separated flow over the airfoil is discussed. The Reynolds number based on chord length is set to 63,000 and the angle of attack is set to 14 [deg]. The DBD plasma actuator is installed at the 0 % and 5 % chord length from the leading edge, and actuated in burst mode. For the burst mode, the nondimensional burst frequency is set to 1 and 6. Through the present analysis, the two mechanisms of separation control are discussed. The first mechanism enhance the vortex shedding from the separation shear layer and avoid the massive separation from the leading edge on burst mode with nondimensional burst frequency of 1. The second mechanism improves the airfoil performance by suppressing the separation region on the burst mode with nondimensional burst frequency of 6. In addition, it is clarified that the first mechanism is more sensitive to the location of the DBD plasma actuator than the second mechanism and it is associated with large fluctuation of lift.