A TWO-FLUID BGK LATTICE BOLTZMANN MODEL FOR IDEAL MIXTURES

摘要

In the present work, a lattice Boltzmann model for binary mixtures is formally derived from a two-fluid kinetic model of Maxwell molecules by discretizing the Boltzmann equation. In this model, collisions among the same and different species are treated separately, as non-linear BGK terms, enabling the independent management of the fluid viscosities and the binary diffusion coefficient. The velocity space is discretized, in accordance with a quadrature method based on prescribed abscissas. A Chapman-Enskog analysis is performed for deriving the macroscopic mass and momentum transport equations. The model is verified against theoretical solutions for the concentration and velocity step problems.