Heat Transfer through Parallel Plate Microchannels at Symmetric and Asymmetric Constant Wall Temperature

Forced convective heat transfer in parallel microchannels with asymmetric and symmetric wall thermal conditions under hydrodynamically and thermally fully developed flow is investigated using control volume technique for steady, two dimensional flow. Incompressible Navier-Stokes and energy equations are solved applying velocity slip and temperature jump boundary conditions on the walls. Simulations are validated comparing with the experimental results available in the literature. Simulations are performed for different temperature difference between the walls and the gas as well as the inlet velocity and ambient pressure conditions. Either the wall heating or wall cooling cases are examined taking Nitrogen gas as the working fluid. The influences of Knudsen number, Reynolds number and temperature difference on Nusselt number are observed. It is shown here that for asymmetric wall thermal condition for temperature dependent thermal conductivity the Nusselt number is lower for higher temperature difference where as for symmetric wall thermal condition Nusselt number is higher for higher temperature difference.