Modified Empirical Model of Surface Dielectric Barrier Discharge Plasma Actuator in Flow Control

Abstract

In this paper, an empirical model of surface dielectric barrier discharge (SDBD) plasma actuator with good prediction performance is proposed based on experimental data. Due to the complex electric field and unstable discharge process of asymmetric dielectric barrier discharge (DBD) plasma actuator, a reliable model used to simulate the macro flow is difficult to develop with small calculation costs according to the first principle. Based on summarizing experimental data and improving other semiempirical models, a new empirical thrust estimation model is developed. The model considers six main parameters affecting the actuator thrust, including voltage amplitude, frequency, upper electrode thickness, lower electrode width, and relative permittivity and thickness of the dielectric. The estimated thrust value is inserted into the Navier–Stokes equation as a body-force source term and then the equation is solved by the computational fluid dynamics (CFD) software FLUENT using the finite volume method combined with the Spalart–Allmaras turbulence model. The body-force region is specified by an empirical body-force distribution function based on velocity information. Grid dependence of the model is verified by three meshes with different resolutions. The effectiveness of the empirical model and body-force distribution is verified by different experimental cases. Thus, the model proposed in this paper can properly predict the thrust value and velocity field generated by the DBD plasma actuator with a small computation cost.