Modeling of Nanosecond Pulsed DBD Plasma Actuator for Flow Control

Abstract

In the present study, a model of dielectric barrier discharge (DBD) driven by nanosecond pulse was developed for flow control analysis. In general, computational analysis of DBD requires to solve Gausss law for electric field, chemical species continuity equation for plasma including electron, positive ions, negative ions, neutral particles and Navier-Stokes equation for fluid. Considering all these governing equations makes computational cost enormously expensive due to their time scale difference. By using quasi-1-dimensional self-similar equation of DBD plasma, the time cost for plasma analysis was reduced dramatically and plasma parameters such as plasma propagation distance, electric field, electron density and joule heating energy can be calculated. The obtained joule heating energy is then utilized to construct a model of dissipating unsteady energy source into fluid by plasma. The model reflected the increase/decrease of the joule heating energy arise from the physical phenomena of electrical current variations during a pulse period. The obtained unsteady energy source term was coupled with Navier-Stokes equation to analyze the flow disturbances made by DBD actuator which produces propagating micro compression wave. The time-varying position of compression wave generated by DBD plasma actuator predicted by developed model was in agreement with previously reported data from experimental and computational analysis. Also, the developed model was able to predict compression wave propagation due to DBD plasma more accurately compared to a model which used steady energy source term.