Stability of a uniform contact surface is investigated in the case when a nonuniform shock wave passes through the surface. The nonuniform shock is generated by a rippled piston that moves with constant velocity. The amplitude of the shock oscillates and decreases as it propagates. A uniform contact surface is found to be unstable after the nonuniform shock passes across it. The growth rate depends sensitively on the phase of the oscillating shock wave at the time when the shock hits the contact surface. The physical mechanism of the instability is qualitatively discussed. The linear and nonlinear evolutions of the instability are studied. In particular, the dependence of the linear case on the Atwood number for a weak shock is investigated. Properties of this stability are found to exhibit differences from those of the standard Richtmyer-Meshkov instability in both the linear and nonlinear cases.

• Received 18 October 1995

DOI:https://doi.org/10.1103/PhysRevE.53.R5592