Abstract
This paper describes the flow, heat transfer and pumping power of the mixed convection in a horizontal square duct with heated and cooled side walls by the three-dimensional numerical analysis. The working fluid is water and the temperature dependence of kinetic viscosity and thermal conductivity of water is considered. The SIMPLE procedure and QUICK scheme are used to solve the governing equations through a control volume. Three-dimensional spiral flows are shown along the longitudinal direction of the duct and swirl flows pitch are shortened with increases of Richardson number Ri (=Gr/Re^2). The recirculation flow appears on the upper and bottom wall edge near the starting point of the heat transfer section. The size of the recirculation flow increases with increase of Ri. The pumping power due to swirl flow was also evaluated.
