Experimental investigation of shock accelerated spherical gas inhomogeneity

The evolution of a spherical gaseous interface accelerated by a plane shock wave has been investigated in a square cross section shock tube via a multiple exposure shadowgraph diagnostic. An helium bubble is introduced in air at atmospheric pressure in order to study the Richtmyer-Meshkov instability in spherical geometry for different shock wave Mach numbers (from 1.05 to 1.75). Focusing our study on the downstream bubble interface velocity and the inhomogeneity global length, we show that the bubble distortion is highly correlated with the shock wave strength.