Slip-flow heat transfer in a microchannel with viscous dissipation

Forced convection flow in a microchannel with constant wall temperature is studied, including viscous dissipation effect. The slip-flow regime is considered by incorporating both the velocity-slip and the temperature-jump conditions at the surface. The energy equation is solved for the developing temperature field using finite integral transform. To increase beta(v) Kn is to increase the slip velocity at the wall surface, and hence to decrease the friction factor. Effects of the parameters beta(v) Kn, beta, and Br on the heat transfer results are illustrated and discussed in detail. For a fixed Br, the Nusselt number may be either higher or lower than those of the continuum regime, depending on the competition between the effects of beta(v) Kn and beta. At a given beta(v) Kn the variation of local Nusselt number becomes more even when beta becomes larger, accompanied by a shorter thermal entrance length. The fully developed Nusselt number decreases with increasing beta irrelevant to beta(v) Kn. The increase in Nusselt number due to viscous heating is found to be more pronounced at small beta(v) Kn.