Single-dielectric barrier discharge plasma actuator modelling and validation

Abstract

Single-dielectric barrier discharge (SDBD) plasma actuators have gained a great deal of world-wide interest for flow-control applications. With this has come the need for flow-interaction models of plasma actuators that can be used in computational flow simulations. SDBD plasma actuators consist of two electrodes: one uncovered and exposed to the air and the other encapsulated by a dielectric material. An AC electric potential is supplied to the electrodes. When the AC potential is large enough, the air in the region over the encapsulated electrode ionizes. The ionized air in the presence of the electric field results in a space–time dependent body force vector field. The body force is the mechanism for flow control. This study describes a semi-empirical model that has been developed to capture the dynamic nature of the local air ionization and time-dependent body force vector distribution. Validation of the model includes comparisons to experimentally measured space–time charge distribution and the time-resolved and time-averaged body force. Two flow simulations are then used to further validate the SDBD plasma actuator model. These involved an impulsively started plasma actuator in still air, and the flow around a circular cylinder in which plasma actuators were used to suppress the Karman vortex street. In both cases, the simulations agreed well with the experiments.