Experimental Study on the Dynamic Characteristics and Surface Arc Plasma Control of Shock Train in the Supersonic Inlet

The oscillation characteristics and morphological changes of the shock train in the inlet expansion section and the control of the shock train by surface arc plasma were studied in Mach 2 supersonic flow. A wedge installed at the exit of the supersonic inlet created a throttling ratio of 50% to generate a shock train in the expansion section. A high-speed schlieren system was employed to capture the flow structure of shock train. The fast Fourier transform (FFT) and snapshot proper orthogonal decomposition (SPOD) methods were employed to identify the oscillations' spectral characteristics and for modal analysis of the shock train, respectively. The results show that the oscillation of lambda leading shock has the characteristics of multipeak frequencies with a range of 300 - 500 Hz , and the Mach disk dominates the low-frequency oscillation characteristics of the lambda leading shock. The surface arc plasma actuation has a significant control effect on the shock train, realizing the conversion of the lambda leading shock to the oblique shock. (C) 2022 American Society of Civil Engineers.