Schlieren Imaging of the Aerodynamic Flow Field Induced by a Paraelectric Electrohydrodynamic (EHD) Plasma Actuator

Schlieren imaging methods respond to density gradients in gases and are used in aerodynamic research to visualize the structure of atmospheric pressure flow fields. We have used this method to study the flow induced in atmospheric pressure air by electrohydrodynamic body forces generated by a single paraelectric plasma actuator energized in the filamentary mode of operation. The schlieren images show the absence of significant vertical flow and also show an induced boundary layer flow no more than a few millimeters thick.