Collaboration and Competition Between Richtmyer-Meshkov instability and Rayleigh-Taylor instability

TL;DR

This paper uses a discrete Boltzmann model to simulate and analyze the interaction between Richtmyer-Meshkov and Rayleigh-Taylor instabilities, revealing their correlation, dominance regions, and effects on material mixing.

Contribution

It introduces a detailed simulation of coexisting RMI and RTI using a multiple-relaxation time discrete Boltzmann model, exploring their interaction mechanisms and influence on mixing.

Findings

High correlation between energy flux and temperature nonuniformity in RMI.

Identification of parameter regions where RMI or RTI dominates.

Effects of gravity and Mach number on non-equilibrium and mixing extent.

Abstract

The two-dimensional Richtmyer-Meshkov Instability(RMI) system and the coexisting system combined with Rayleigh-Taylor Instability(RTI) are simulated with a multiple-relaxation time discrete Boltzmann model. It is found that, for the RMI system, the correlation between globally averaged non-organized energy flux and nonuniformity of temperature is nearly 1; the correlation between globally averaged non-organized momentum flux and nonuniformity of velocity and that between globally averaged thermodynamic non-equilibrium strength and nonuniformity of density are also high. In the coexisting system combined with RTI, the collaboration and competition mechanisms of the two instabilities are investigated. In the case where RMI dominates, an interesting interface inversion process is observed. The parameter regions for RMI dominates and RTI dominates are given. The effects of gravity acceleration and Mach number on nonequilibrium are carefully studied, via which the effects of RTI and RMI strengths on the extent of material mixing are better probed.