Effect of viscous dissipation on laminar mixed convection in a horizontal channel

Abstract

Laminar mixed convection in a horizontal channel is studied analytically in the fully developed region when the effect of viscous dissipation cannot be neglected. Two kinds of thermal boundary conditions are considered: uniform wall temperatures and uniform wall heat fluxes. Velocity and temperature profiles and the Nusselt numbers have been determined in a closed form. The results show that when viscous dissipation is taken into consideration, temperature profiles and Nusselt numbers are significantly affected by the Brinkman number while velocity profiles are independent of the Brinkman number.