The e®ects of thermal creep on the development of gaseous °uid °ow and heat transfer in rectangular microchannels with constant wall temperature are investigated in the slip-°ow regime. Thermal creep arises from tangential temperature gradients, which may be signi¯cant in the entrance region of channels, and a®ects the velocity and temperature ¯elds particularly in low Reynolds number °ows. In the present work, the Navier
Stokes and energy equations coupled with velocity-slip and temperature-jump conditions applied at the channel walls are solved numerically using a control-volume technique. Despite the constant wall temperature, tangential temperature gradients form in the gas layer adjacent to the wall due to the temperature-jump condition. The e®ects of slip/jump and thermal creep on the °ow patterns and parameters are studied in detail for a wide range of channel aspect ratios and, Knudsen and Reynolds numbers. Furthermore, the e®ects of variable properties on velocity-slip and, friction and heat transfer coe±cients are also examined.

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