Effects of back pressure fluctuation on pseudo-shock waves in a rectangular duct

Pseudo-shock waves in a scramjet isolator are worth studying. These waves are generally subjected to back pressure fluctuation induced by combustion. The characteristics and unsteadiness mechanism of pseudo-shock waves are investigated using a numerical method. A second nozzle with a movable pintle is utilized to simulate the back pressure fluctuation of a combustion chamber in the numerical model. A 2D numerical method with the kω-shear stress transport turbulence model is adopted to investigate the behavior of pseudo-shock waves. Validation of the numerical model is performed by comparing its results with existing experimental results. The accuracy of the numerical model is proven. The present study aims to investigate the unsteady characteristics of pseudo-shock waves in a scramjet isolator. As indicated by the results, the amplitude of pseudo-shock wave motion can be reduced by increasing the exciting frequency of back pressure fluctuation. The influence mechanism of exciting frequency is the phase difference caused by time delay.