Experimental study of symmetric and asymmetric shock-shock interactions with variable inflow Mach numbers

An experimental investigation of shock-shock interactions has been conducted with the aim of studying the transition between Regular (RI) and Mach (MI) interactions induced by a variation of the inflow Mach number. The experiments were conducted in the TST-27 wind tunnel at Delft University of Technology. For all cases, the wind tunnel runs were initialized in the RI domain after which the Mach number was slowly decreased to the MI domain, thereby traversing the whole dual solution domain. The process was then inverted to reach again the RI domain in order to investigate a possible transition hysteresis. Both conventional Schlieren and Focusing Schlieren systems were used to visualize the shock wave patterns. The recorded Schlieren images allow accurate transition detection together with quantitative measurements of the Mach Stem Heigth (MSH). The results show no hysteresis effects. All transitions are recorded to occur at the von Neuman line, for both RI to MI and MI to RI cases.