Slip Flow Convection Heat Transfer in a Rectangular Microchannel with Exponential Wall Heat Flux

entry region of a rectangular microchannel is investigated. The wall heat flux is peripherally constant and varies exponentially with respect to the axis of the microchannel. The flow is assumed to be hydrodynamically fully developed. The three-dimensional energy conservation equation is solved numerically for different aspect ratios. Surface interaction parameters consist of momentum accommodation coefficient and thermal accommodation coefficient, are introduced to the simulation and their effects on heat transfer is investigated. The fully-developed Nusselt numbers are obtained for different values of the parameter defined in the exponential function of heat flux. For a special case, i.e., constant wall heat flux, the results are compared with those presented in literature. It was observed that two dimensionless variables that include rarefaction and surface interactions affect Nusselt number. For a specific value of thermal dimensionless variable, there is a transition region between continuum regime and slip-flow regime. Beyond this value, Nusselt number decreases as the momentum dimensionless variable increases.