Effects of viscous dissipation and fluid axial heat conduction on laminar heat transfer in ducts with constant wall temperature

Abstract

Thermally developing laminar non-Newtonian fluid flow through annular channel with constant wall temperature has been studied including both viscous dissipation and fluid axial heat conduction effects. A numerical scheme based on the finite difference method was applied to solve the governing elliptic type energy equation for two semi infinite domains. The results are given for the radius ratio of R(sup *) = 0.2, 0.5 and 0.8 and the effects of the Brinkman number and the Peclet number on the developing temperature profiles and on the Nusselt number at the walls are discussed. Analytical expressions for the local Nusselt number and for the developing temperature profile of Newtonian fluids in a tube are obtained by considering the viscous dissipation effect for the confirmation purpose.