Mathematical modelling of the mass transfer process between two coaxial cylinders in the problem of thermal creep

An analytic solution to the Williams equation in the thermal creep flow problem in the channel, formed by two coaxial cylinders, has been constructed using the kinetic approach. For the boundary condition on the channel walls, the diffusion model is used. Taking into account the constructed distribution function for various values of the ratio of radii of cylinders and Knudsen number, the value of the mass flow rate in channel is calculated. The analysis of the obtained results during the transition to free molecular and hydrodynamic regimes is done.