New velocity-slip and temperature-jump boundary conditions for Navier–Stokes computation of gas mixture flows in microgeometries

Recently, several kinetic descriptions have been utilized for the simulation of gas mixture flows in microgeometries. Although such developments are important, Navier–Stokes computation can find extended use in engineering applications. In the present contribution, a rarefied flow of a gas mixture in the vicinity of a wall is concerned and new velocity-slip and temperature-jump boundary conditions are derived for the whole mixture. Appealing to these new boundary conditions, Navier–Stokes computation of microscale gas mixture flows becomes feasible. Consequently, the proposed conditions in conjunction with the Navier–Stokes equations and an equation for the conservation of species are solved for a He–Ne flow in a microchannel and suitability of the derived boundary conditions is demonstrated in the slip flow regime.

• We derive new velocity-slip and temperature-jump boundary conditions for rarefied multicomponent problems. • Appealing to these boundary conditions, Navier–Stokes computation of microscale gas mixture flows becomes feasible. • We undertake a Navier-Stokes computation for a He–Ne flow in a microchannel and demonstrate the suitability of the proposed boundary conditions in the slip flow regime.