Forced Convection Heat Transfer of Non-Newtonian Fluids Through Circular Ducts

The Galerkin finite element method is used to solve the three dimensional continuity, momentum and energy equations for laminar Newtonian and power-law model non-Newtonian flow through horizontal circular tube. The governing equations are non-dimensionalized with respect to specific variables and converted into algebraic equations using appropriate elements. To accelerate convergence a combination strategy of fixed iteration and Newton-Raphson methods are employed. Uniform wall temperature as well as constant wall heat flux are used as thermal boundary conditions. Apparent friction factor and incremental pressure drop and also Nusselt number are obtained for a wide range of power-law indices. The effects of thermal boundary conditions and Prandtl number on heat transfer characteristics are presented and discussed.