Numerical Prediction of Slip Flow and Heat Transfer in Microchannels

Rarefied gas slip microflow and heat transfer in rectangular microchannels and backward facing steps are numerically investigated. A control-volume based numerical method is used to solve the Navier–Stokes and energy equations with velocity-slip and temperature-jump conditions at the walls. The effects of Knudsen number (Kn ! 0.1), thermal creep, and viscous heating on the velocity and temperature fields are investigated for the microchannel flow. The present numerical results are compared to analytical and other numerical data for validation purposes. In addition, key flow parameters like the entrance length and Nusselt number are examined in detail. For the flow along a microchannel with sudden enlargement or backward facing step, the effects of the step on separation, reattachment, and velocity slip and temperature jump at various locations in the domain were investigated.