Numerical Simulation of the Instability Development in a Compressible Mixing Layer Using Kinetic and Continuum Approaches

The Kelvin-Helmholtz instability developing in the compressible mixing layer is simulated numerically using both the kinetic and continuum approaches. The computations are performed for a spatially periodic mixing layer at subsonic convective Mach numbers and low Reynolds numbers. The main part of the kinetic simulations are carried out with the Shakhov model kinetic equation but the simulations based on the Boltzmann equation are also conducted. A deterministic numerical method that directly solves the kinetic equations on a finite-difference grid in the multidimensional phase space is used. The computational code is adapted for implementation on hybrid computational clusters combining CPUs and GPUs. Navier-Stokes simulations of the Kelvin-Helmholtz instability are also performed and their results are compared with those of kinetic simulations.