Slip-flow heat transfer in rectangular microchannels

Laminar slip-flow forced convection in rectangular microchannels is studied analytically by applying a modified generalized integral transform technique to solve the energy equation, assuming hydrodynamically fully developed flow. Results are given in terms of the fluid mixed mean temperature, and both local and fully developed mean Nusselt numbers. Heat transfer is found to increase, decrease, or remain unchanged, compared to non-slip-flow conditions, depending on two dimensionless variables that include effects of rarefaction and the fluid/wall interaction. The transition point at which the switch from heat transfer enhancement to reduction occurs is identified for different aspect ratios.