Model comparison of DBD-PA-induced body force in quiescent air and separated flow over NACA0015

Abstract

Numerical simulations of plasma flow induced by dielectric barrier discharge plasma actuators (DBD-PA) are conducted with two different body-force models: Suzen-Huang (S-H) model and drift-diffusion (D-D) model. The induced flow generated in quiescent air over a flat plate in continuous actuation and the PA-based flow control effect with burst actuation in separated flow over NACA0015 is studied. In the comparative study, the body-force field and the induced velocity field are firstly investigated in the quiescent field to see the spatial difference and the temporal difference in a single discharge cycle. The D-D body force is computed with flush-mounted and bulge configuration of the exposed electrode, which is operated at the peak-to-peak AC voltage of 7kV and 10kV. The D-D models generate momentarily higher body force in the positive-going phase of the AC power, but activate a smaller flow region than the S-H model with Dc = 0.0117, which is given by the experiment beforehand at 7kV. The local induced velocity of the D-D bulge case at 7kV measured in the downstream flow has the best agreement with the experimental result. The maximum wall-parallel induced velocity in the S-H case with Dc = 0.0117 is consistent with that in the experiment, however, the local induced velocity is relatively high with different flow structures. In the post-stall flow over the airfoil at the angle of attack of 12 degrees and Reynolds number of 63000, the D-D bulge model at 7kV has approximately the same effect of leading-edge suction enhancement and reattachment promotion as the S-H model with Dc = 0.16, which was previously proved to be sufficiently high to achieve the control performance.