Modeling and flow characteristics investigation of a microsecond pulsed localized arc filament plasma actuator operating in atmosphere

This article introduces a novel actuator model for the operation of the microsecond pulsed localized arc filament plasma actuator (LAFPA) in atmospheric environment, validated through experimental data. By comparing the evolution of the induced thermal bubble shape, the momentum effect of the actuator is demonstrated. The proposed body force model, combined with the heating model, significantly outperforms the conventional heating model in simulating the arc discharge phenomenon. To understand the impact of designed parameters on the performance of the arc-discharge plasma actuator, multiple configurations of the LAFPA were investigated. These included variations in power frequencies (0.5–2 kHz) and electrode positions relative to the wall (−2–2 mm), such as flush-mounted, outside the wall, and within a cavity. The actuator operating at a low frequency (0.5 kHz) generates a relatively small interaction area, whereas increasing the frequency to 1 kHz significantly enlarges the overall interaction area. However, further increasing the frequency to 2 kHz does not result in a substantial expansion of the interaction area. The geometrical effect on the induced flow during LAFPA operation is numerically investigated using the validated plasma model. Distinct thermal evolution patterns observed for different electrode positions indicate potential applications for flow control under various operating conditions. Notably, the electrode placement in the cavity (−2 mm) suggests that part of the actuator's forcing mechanism behaves more like a fluidic device than a purely thermal actuator. This configuration enables the retention of high temperatures between actuation cycles, thereby enhancing the overall actuator performance.