Experimental Investigation on Richtmyer-Meshkov Instability of a "V" Shaped Interface Subjected to Shock Wave

The Richtmyer-Meshkov instability of a "V" shaped air/SF₆ interface accelerated by a planar incident shock and its reshock was experimentally investigated in a shock tube.The soap film technique was adopted to form a well-controllable initial interface, and the flow field was captured by a high-speed schlieren system.Through changing the vertex angle of the interface, the initial perturbation amplitude was varied, and the effect of the initial perturbation amplitude on the wave pattern and the flow morphology was highlighted.The results show that, after the impact of the incident shock, the interface morphology is different for different vertex angles, further causing the diversity of the interface morphology after the reshock impact.For the interfaces with small vertex angles, the complicated wave patterns will emerge inside and outside the interface after the reshock, which exert an influence on the interface morphology and phase inversion phenomenon.The flow enters the turbulent mixing quickly after the reshock, and the development of interface for small vertex angles tends towards isotropy.Moreover, the mixing width after the reshock was measured from experiments and compared with the theoretical predictions.The model was found to be invalid mainly because the initial conditions of the experiments violate the requirement of the model.