Development of multicomponent lattice Boltzmann flux solver for simulation of compressible viscous reacting flows

In this paper, the multicomponent lattice Boltzmann flux solver (LBFS) is developed for simulation of two-dimensional compressible viscous reacting flows. This work is based on the existing LBFS for simulation of single-component compressible flows. The present solver applies the finite volume method to discretize the multicomponent Navier-Stokes equations and evaluates the numerical flux at the cell interface by local solution of the lattice Boltzmann equation. To evaluate numerical flux, the original non-free parameter D1Q4 model in the existing LBFS is extended to the multicomponent counterpart in which the total density at the cell interface is computed directly by summing the density distribution functions, and the densities of different species are calculated from the mass fractions at the left and right sides of cell interface. The internal energy is evaluated from the enthalpy which considers the different physical properties of the species, and the temperature at the cell interface is obtained by Newton iteration. In addition, an improved switch function which takes into account the reacting effects and aspect ratio of the grid is introduced to control the numerical dissipation. Several benchmark problems are simulated to validate the present multicomponent LBFS. It is shown that the present solver is carbuncle-free for the unfavorable aspect ratio grid in the test cases here and has a satisfied performance for simulation of multicomponent compressible viscous reacting flows.