Viscous Dissipation and Fluid Axial Heat Conduction Effect on the Heat Transfer to a Laminar Non-Newtonian Fluid Flow in Cylindrical Annular Duct with an Axially Moving Core

Abstract

Heat transfer involved with non-Newtonian fluid flows is encountered in material processing for the shipbuilding as well as other heavy machinery industries. In such applications particularly for drawing, extrusion, coating, etc., the thermal procedures involve the combined form of Couette and Poiseuille flows as the axially moving cylindrical rod continuously exchanges heat with the surrounding environment. In this numerical study, using the fully developed laminar velocity field obtained by applying the modified power-law model, the effects of viscous dissipation and fluid axial heat conduction on thermally developing heat transfer of non-Newtonian fluids flowing in a concentric annulus with a moving core are investigated for the thermal boundary conditions of constant temperature and/or constant heat flux at the cylinder walls. The flow temperature distribution is obtained for an axially infinite extent by solving the elliptic type energy equation and the solution is based on a coordinate transformation.