Effects of unsteady shock impingement on high-speed gaseous mixing

Tests are performed to determine the effects of impinging oscillating shocks of different frequencies on a 15 deg downstream angled, underexpanded, sonic helium jet injected into a supersonic airflow. Information on mixing, penetration, total pressure loss, and turbulence structure from these tests is employed to estimate mixing control achieved by adding an oscillating shock to the helium injection flow field. The principal result of this study is that impingement of an oscillating shock on a high-speed shear layer can be utilized to control the rate of mixing.