Abstract
Interactions between turbulent boundary layer and single-incident or dual-incident shock waves are commonly observed in supersonic inlets. To provide novel insights into the unsteadiness of these interactions, six incident shock wave/turbulent boundary layer interactions (ISWTBLIs), including both single-ISWTBLIs and dual-ISWTBLIs, are experimentally investigated using dynamic wall-pressure measurements at Mach 2.73 flow conditions. Through spectral analysis and correlation analysis, the unsteadiness characteristics of single-ISWTBLIs and dual-ISWTBLIs are comparatively examined, revealing significant influences of shock-wave strength and shock-wave distance on low-frequency unsteadiness. Specifically, both regions near the separation and reattachment points exhibit distinct low-frequency unsteadiness in single-ISWTBLIs and dual-ISWTBLIs with relatively strong separations. An increase in the deflection angle from 10° to 12° in single-ISWTBLIs extends the streamwise separation length, while causing a dramatic decrease in both characteristic frequency and normalized characteristic frequency (Strouhal number) of low-frequency unsteadiness. However, for dual-ISWTBLIs, as the shock-wave distance increases, there is an initial increase followed by a subsequent decrease in the separation length accompanied by a continuously increasing characteristic frequency, thus indicating a different relationship between separation length and characteristic frequency of unsteadiness in dual-ISWTBLIs in comparison with that observed in single-ISWTBLIs. Moreover, correlation analysis revealed that the pressure signals in the reattachment region are of strong negative correlation with those near the separation-shock foot, and the correlation increases with increasing shock-wave strength in single-ISWTBLIs and decreasing shock-wave distance in dual-ISWTBLIs.
Funder
National Natural Science Foundation of China
National Science and Technology Major Project
Science Center of Gas Turbine Project
Subject
Condensed Matter Physics,Fluid Flow and Transfer Processes,Mechanics of Materials,Computational Mechanics,Mechanical Engineering