Front tracking simulations of the Richtmyer-Meshkov instability produce significantly better agreement with experimentally measured growth rates than obtained in nontracking computations. Careful analysis of the early stages of the shock acceleration process show that nonlinearity and compressibility play a critical role in the behaviour of the shocked interface and are responsible for the deviations from the linear theories. The late-time behaviour of the interface growth rate is compared to a nonlinear potential flow model of Hecht et al.

Richtmyer–Meshkov instability is investigated for negative Atwood number and two-dimensional sinusoidal perturbations by comparing experiments, numerical simulations and analytic theories. The experiments were conducted on the NOVA laser with strong radiatively driven shocks with Mach numbers greater than 10. Three different hydrodynamics codes (RAGE, PROMETHEUS and FronTier) reproduce the amplitude evolution and the gross features in the experiment while the fine-scale features differ in the different numerical techniques. Linearized theories correctly calculate the growth rates at small amplitude and early time, but fail at large amplitude and late time. A nonlinear theory using asymptotic matching between the linear theory and a potential flow model shows much better agreement with the late-time and large-amplitude growth rates found in the experiments and simulations. We vary the incident shock strength and initial perturbation amplitude to study the behaviour of the simulations and theory and to study the effects of compression and nonlinearity.