Mass flux and gas pressure distribution in a long concentric annular channel in the case of incomplete accommodation of gas molecules

The solution of the linearized problem of isothermal rarefied gas flow in a long concentric annular channel is found depending on the tangential momentum accommodation coefficient. The process is described by the Bhatnagar–Gross–Krook model kinetic equation, and the boundary condition is specified using the model of specular-diffuse reflection of gas molecules from the channel walls. The mass flux and the pressure distribution over the channel length are obtained for arbitrary values of the rarefaction parameter. They are analyzed in the free-molecular and hydrodynamic gas flow regimes in the channel.