A non-equilibrium bounce-back boundary condition for thermal multispeed LBM

Abstract

High-order lattice Boltzmann methods provide an elegant and systematic way to incorporate thermal and compressible effects and represent a promising approach for the study of beyond-hydrodynamics regimes characterized by finite Knudsen numbers. However, the presence of multiple layers makes the definition of boundary conditions non-trivial, since one needs to define the missing information for particle distributions across several boundary layers. In this work we present a thermal extension of a recently proposed non-equilibrium bounce-back boundary condition and compare it against established algorithms by simulating standard benchmarks with wall-bounded flows.