Velocity measurements in turbulent gaseous mixtures induced by Richtmyer–Meshkov instability

Abstract

Instantaneous velocity measurements in a gaseous mixture arising from the shock wave-induced Richtmyer–Meshkov instability are conducted for the first time in a shock tube. Laser Doppler anemometry gives us the evolution of the axial velocity fluctuations of the mixing zone, before and after its interactions with reflected shock waves from the shock tube end wall. Experimental results demonstrate that a turbulent mixing zone is generated by the incident shock wave. Afterwards, the axial variance decreases before being amplified by the first reshock interaction through a baroclinic effect. Before the second reshock arrival, we measure once again a decrease of the turbulence level which is explained by both diffusion and dissipation.