Control of Supersonic Cavity Flow Using Plasma Actuators

摘要

Cavity flows are present in a wide range of aerospace applications. The pressure fluctuations associated with cavity resonance have made them the target of significant flow control efforts aimed at suppressing resonance. A potential scramjet application for cavity flows may require resonance enhancement in addition to resonance suppression. Localized arc filament plasma actuators have demonstrated the ability to control a high subsonic cavity flow. This work investigates the control authority of the localized arc filament plasma actuators in a supersonic (M = 2.24) cavity flow. The localized arc filament plasma actuators significantly suppress the primary cavity resonance of a naturally and strongly resonating cavity. Additionally, the trend in effectiveness suggests that introducing mode competition through the excitation of the Kelvin-Helmholtz instability, and thereby influencing the shear-layer structure formation process, is the likely control mechanism. The effects of two-dimensional and three-dimensional excitation are explored. Although two-dimensional excitation achieves the greatest resonance suppression, three-dimensional excitation shows similar suppression with significantly less sensitivity to the excitation Strouhal number, making it more desirable for practical applications. In a weakly resonating cavity, the flow significantly responds to excitation near the resonance Strouhal numbers. However, electromagnetic interference makes it difficult to quantify the level of resonance enhancement.