Effect of a moving wall on the separation of a gas mixture

The behavior of the steady flow of a binary gas mixture without chemical reactions in a plane channel with moving walls is studied numerically. The Knudsen number region ranges from the transition region to that of free molecular flow (Kn exceeds 2). The nonlinear Bhatnagar-Gross-Krook model is used to formulate the shock operator collision operator necessary for the numerical solution, accomplished using the discrete ordinate method of Huang, of the Boltzmann equation describing molecular collisions in gases. The interaction of molecules with the moving wall is said to be a diffuse reflection process.