This paper describes the development and application of an efficient hybrid continuum-molecular approach for simulating non-isothermal, low-speed, internal rarefied gas flows, and its application to flows in Knudsen compressors. The method is an extension of the hybrid approach presented by Patronis et al. (2013) [J. Comp. Phys., 255, pp 558–571], which is based on the framework originally proposed by Borg et al. (2013) [J. Comp. Phys., 233, pp 400–413] for the simulation of micro/nano flows of high-aspect-ratio.
The efficiency of the multiscale method allows the investigation of alternative Knudsen-compressor configurations to be undertaken. We characterise the effectiveness of the single-stage Knudsen-compressor channel by the pressure differential that can be achieved between two connected reservoirs, for a given temperature difference. Our multiscale simulations indicate that the efficiency of the single-stage Knudsen compressor is robust to modifications of the streamwise temperature variation.