Effects of expansion waves on incident shock-wave/boundary-layer interactions in hypersonic flows

Abstract

The effects of expansion waves on incident shock-wave/boundary-layer interactions (SWBLIs) at a Mach number of 4.96 are experimentally studied. The flow characteristics of the interaction zone under various intensities and positions of the incident shock wave and expansion waves are quantitatively analyzed. The expansion waves weaken the intensity of the shock waves encountered, thereby weakening the intensity of the SWBLIs. With an increasing distance between the expansion waves and the interaction zone, the total wall pressure jump and the interference length show a linear growth trend. However, the expansion waves do not affect the initial pressure jump of the separation, which is consistent with free-interaction theory. Finally, the scaling model proposed by Souverein et al. [“A scaling analysis for turbulent shock-wave/boundary-layer interactions,” J. Fluid Mech. 714, 505 (2013)] is simply modified using the measured value of the pressure jump. This correction provides a better approximate result for SWBLIs under the impact of expansion waves.