Implications of Imposing Working Gas Temperature Change Limits on Thermal Creep Driven Flows

Experimental studies have indicated that the performance of a Knudsen Compressor stage (which includes a membrane section and a connector section) was limited by rarefaction effects, specifically reverse thermal creep flow inside the connector section. Simulation studies, using the DSMC technique were conducted to quantify the influence of these rarefaction effects in the connector sections. For the simulations two limiting cases have been studied: a linear temperature gradient imposed along the horizontal wall of the connector section; and a step temperature function (temperature discontinuity) positioned along the vertical wall of the connector section adjacent to the membrane exit, which mimics the experimental Knudsen Compressor stage setup. Previous results for various connector channel Knudsen number (KnH/2) were obtained by changing the sizes of the connector section, while keeping constant membrane channel Knudsen numbers (Knh/2∼2.7). The present work examines the influence of changing KnH/2 and K...