Measurement of corner separation zone response on a compression ramp to plasma actuation within the hypersonic boundary layer

14th International Conference on Fluid Control, Measurements and Visualization

Hedlund, Brock E.^1 ; Houpt, Alec W.^1 ; Gordeyev, Stanislav V.^1 ; Leonov, Sergey B.^1

Institute for Flow Physics and Control, University of Notre Dame, Notre Dame

IN

46556, United States^1

关键词: Compression ramps;    Corner separation;    Dominant frequency;    Forcing frequencies;    Natural disturbance;    Shack-Hartmann wavefront sensors;    Transient plasmas;    Transition to turbulence;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/249/1/012013/pdf
DOI  :  10.1088/1757-899X/249/1/012013

来源: IOP

【 摘 要 】

This study was performed to characterize the dominant frequencies present in the boundary layer uptsream of and in the corner separation zone of a compression surface in Mach 4.5 flow and to determine a control effect of transient plasma actuation on the boundary layer. Schlieren imaging was used to distinguish the corner separation zone for 20°, 25°, and 30° compression ramps mounted on flat plates. Spectra of the natural disturbances present in the boundary layer and separation zone were gathered using a high-speed Shack-Hartmann wavefront sensor and surface mounted PCBTMpressure sensors while varying flow parameters by adjusting total pressure, temperature, and ramp angle. Shallow cavity discharge plasma actuators were used as a high-frequency localized thermal forcing mechanism of the boundary layer. The plasma effect was negligible for forcing frequencies (50 kHz) below the natural dominant frequency (∼55-80 kHz). High frequency perturbations that can promote the transition to turbulence were amplified when the plasma forcing frequency (100 kHz) was higher than the natural dominant frequency (∼55-80 kHz). This technique can potentially be used for active control of hypersonic boundary layer transition and the supersonic flow structure on the compression surface.