The Effect of Surface Conductivity on the Characteristics of the Dielectric Barrier Discharge Actuator

The effect of the surface conductivity on the electrical and mechanical characteristics of the surface dielectric barrier discharge (SDBD) actuator has been numerically investigated in this study. A typical wire-to-plate AC-SDBD actuator to control airflow alongside a flat dielectric plate has been considered. A sinusoidal high voltage of varied frequencies and amplitudes is supplied to the 300-micrometer diameter active electrode, and the passive electrode is encapsulated inside a dielectric plate. Two-species ion transport model, involving generic positive and negative ions, coupled to electrostatics model is assumed. The electrostatic field is affected by both the space and the surface charges. The surface charge is accumulated due to ion deposition, but its distribution varies due to the surface ohmic conduction. The Navier-Stokes equations for the flow simulation, which include the time-averaged electrohydrodynamic (EHD) body force determined from the discharge model, are solved to analyze the flow field and the boundary layer morphology. The numerical algorithm has been implemented in COMSOL commercial package. The significance of the dielectric surface conductivity on the discharge behavior and the flow field has been shown. The dielectric surface conductivity behaves non-monotonically and affects the flow field by altering the EHD force strength, direction and distribution.