Shock Train Leading Edge Detection Method under the Condition of Steady Back Pressure and Fluctuating Back Pressure

Abstract In this paper, the shock train in isolator is taken as research object, and method of detecting leading edge position during self-excited oscillation forced studied by conducting wind tunnel test. A steady-state throttling system a fluctuating are designed to apply required back pressure downstream isolator. Then, four methods ratio method, difference standard deviation Fast Fourier Transform (FFT) analysis used detect study under steady verify their applicability. The results show that condition pressure, can get effective results, consistent. Under could not give but other three consistent results. And similar image principle.