A parametric study on control authority and vorticity transport in a compressor airfoil with plasma actuation at low Reynolds number

In order to obtain the general criterion of control authority for suppressing flow separation in the compressor airfoil at low Reynolds number by nanosecond pulsed dielectric barrier discharge plasma actuation with different actuation parameters, a parametric study on the actuation power and actuation frequency is performed using a large eddy simulation. A non-dimensional actuation power is proposed to reveal the relationship between the actuation power and the characteristic power of the baseline flow field, in order to provide a reference for obtaining a balance between energy consumption and flow control. With different actuation powers, the mechanism behind the evolution process of vortex structures induced by the plasma actuation is revealed through a decomposition of the vorticity according to the vorticity transport equation and the analysis of the non-dimensional circulation according to the Q criterion. It is found that the evolution shows a relatively consistent tendency and can be divided into three stages corresponding to different disturbance processes induced by Kelvin-Helmholtz instabilities. Finally, a criterion for the effective actuation frequency based on the continuous generation of induced vortex structures is established considering different actuation powers and simplified to specific parameters within the flow field.