Analysis Of Turbulent Combined Heat Transfer (Mixed Convection-Thermal Radiation) Heat Transfer in a Vertical Three Dimensional Duct With Variable Thermo-physical Properties

The aim of the present paper is to analyse the effect of thermal radiation on turbulent mixed convection in a vertical duct with variable thermos-physical properties. The Reynolds number based on duct width is 6200 and the Grashof number based on duct width and hot to cold wall temperature difference is 107. The right wall is the hot wall and buoyancy effect in its vicinity is aiding where the left wall is cold and buoyancy effect in its vicinity is opposing. Changes of dynamic viscosity and thermal conductivity of the medium follow the power law. Density is based on the perfect gas equation of state. Results show that with the presence of thermal radiation, due to the reduction in bouyancy effects, temperature profiles become more flattened. Also, radiation causes an increase in heat transfer on both the aiding and opposing sides whereby the velocity gradient reduces on the aiding side and increases on opposing side. Also, the assumption of variable properties results in a reduction of the velocity and temperature gradients on the aiding side and an augmentation on the opposing side.