High-resolution vortex simulations of the Richtmyer-Meshkov instability

Abstract

We perform numerical simulations for the Richtmyer-Meshkov instability by employing an adaptive vortex method, and we present the late-time nonlinear evolution of the unstable interface. The adaptive vortex method takes much longer times than previous vortex simulations and gives results for the highly distorted interfaces in fine resolutions. For a small density jump, only the inner core of the interface is distorted on a small scale, yielding a secondary instability, but the interface maintains a global structure of the uniform roll-up. For a moderate density jump, the interface has stronger distortions on the roll-up overall and develops to a more complex structure. We also compare the numerical results with solutions of theoretical models and examine disagreements between the theoretical models for the Richtmyer-Meshkov instability. The numerical results are in good agreement with a potential source-flow model and show convergence of the bubble curvature to a constant limit.