Nonequilibrium kinetics effects in Richtmyer–Meshkov instability and reshock processes

Abstract

Abstract Kinetic effects in the inertial confinement fusion ignition process are far from clear. In this work, we study the Richtmyer–Meshkov instability and reshock processes by using a two-fluid discrete Boltzmann method. The work begins by interpreting the experiment conducted by Collins and Jacobs (2002, J. Fluid Mech. 464, 113–136). It shows that the shock wave causes substances in close proximity to the substance interface to deviate more significantly from their thermodynamic equilibrium state. The thermodynamic non-equilibrium (TNE) quantities exhibit complex but inspiring kinetic effects in the shock process and behind the shock front. The kinetic effects are detected by two sets of TNE quantities. The first set includes Δ 2 * , Δ 3 , 1 * , Δ 3 * , and Δ 4 , 2 * , which correspond to the intensities of the non-organized momentum Flux (NOMF), Non-Organized Energy Flux (NOEF), the flux of NOMF and the flux of NOEF. All four TNE measures abruptly increase in the shock process. The second set of TNE quantities includes S ̇ NOMF , S ̇ NOEF and S ̇ sum , which denote the entropy production rates due to NOMF, NOEF and their summation, respectively. The mixing zone is the primary contributor to S ̇ NOEF , while the flow field region outside of the mixing zone is the primary contributor to S ̇ NOMF . Additionally, each substance exhibits different behaviors in terms of entropy production rate, and the lighter fluid has a higher entropy production rate than the heavier fluid.