Rarefied flow in a channel and a periodic system of channels (Q1592053)

The steady two-dimensional isothermal rarefied flow in a channel between two parallel flat plates of finite length is studied on the basis of numerical solution of a linearized kinetic problem. The channel may either be isolated or constitute a cell of a periodic cascade consisting of zero-thickness plates arranged one above the other. As the channel length increases, the flow in it approaches asymptotically the one-dimensional Poiseuille flow. The author shows that the asymptotic dependence of the gas flow rate on low Knudsen number corresponding to an infinitely long channel is already attained for a channel of length equal to several channel ends. The author investigates also the effect of boundary conditions imposed on the channel entrance.