Results on the viscous slip coefficient for binary gas mixtures

Abstract

The viscous slip coefficients for the binary gas mixtures of Ne-Ar, He-Ar and He-Xe are estimated by solving the McCormack kinetic model equation subject to Maxwell diffuse-specular scattering boundary conditions. The kinetic equations are solved, by using a semi-analytical version of the discrete ordinates method. For each binary gas mixture the results are presented in table form for many values of the molar concentration of the species and the accommodation coefficients. It is found that the viscous slip coefficient strongly depends on the properties of the mixture (molar concentration, molecular mass ratios, accommodation coefficients) and some of the conclusions are generalized for other binary gas mixtures. It is also seen that the well-known Maxwell analytical result as well as the corresponding results of the complete solution of the kinetic equations for single gases are not valid. The results of the present work can be used for the effective implementation of the Navier-Stokes equations with slip boundary conditions when the flow of binary mixtures in the slip regime is investigated.