Laminar forced convection of power-law fluids in the entrance region of parallel plates ducts

Abstract

An approximate analytical solution for forced convection of power-law fluids in the entrance region of parallel-plates ducts with the uniform heat flux boundary condition (H condition) is presented and analyzed. It is based on the assumption of similarity between the profiles of the velocity and the temperature in the respective boundary layers and in the fully developed region where exact analytical profiles are obtained from the differential conservation equations. The axial evolutions of the hydrodynamic and thermal boundary layers, of the pressure loss, of the skin friction coefficient and of the Nusselt number are also obtained by applying the integral form of the conservation equations in the entrance region. For a f lowbehavior index equal to unity (Newtonian fluid) the predicted values of these parameters are in good agreement with corresponding data from the literature