Non-isothermal gas flow through a rectangular microchannels

The mass flow rate of a rarefied gas through a long rectangular channel caused by both pressure and temperature differences has been calculated applying the S model kinetic equation. The calculations have been carried out in the wide ranges of the four parameters determining the solution of the problem: the gas rarefaction, the height-to-width ratio of the channel, the pressure ratio on the channel ends and the analogous temperature ratio. First, the Poiseuille flow and the thermal creep have been calculated as a function of the local rarefaction parameter assuming the pressure and the temperature gradients to be small. Then, the total mass flow rate has been calculated for the temperature ratio equal to 3.8 and for two values of the pressure ratio: 1 and 100.