A numerical study of steady state laminar forced and free convective and radiative heat transfer in an inclined rotating rectangular duct with a centered circular tube is reported for an hydrodynamically fully developed flow. The two heat transfer mechanisms of convection and radiation are treated independently and simultaneously. The coupled equations of momentum and energy transports are solved using Gauss-Seidel iteration technique subject to given boundary constraints. A thermal boundary condition of uniform wall temperature in the flow direction is considered. A special discritization method is employed to solve the problem associated with near boundary grid points. Results for mean and total mean Nusselt numbers for various values of Reynolds number ,Re; Rayleigh number , Ra ; Geometric ratio ,r g ; Aspect ratio, rA ; Radiation-Conduction parameter , . ; Optical thickness, <FONT FACE=Symbol>J</FONT> ; Rotational Reynolds number ,Ro and Emissivity, epsilon ; are presented. For the range of parameters considered, results show that radiation and rotation enhance heat transfer. It is also indicated in the results that heat transfer from the surface of the circle exceeds that of the rectangle. Optimum heat transfer and fluid bulk temperature are attained when the duct is vertically positioned. The Parameter ranges of 0.2 # r g # 0.84, 0 # PeRa # 7.3 x 10(5) and r g rA # 1 demarcate the extent of the validity of the numerical solution.
Mixed Convective; Radiative; Heat Transfer; Inclined, Rotating; Rectangular Duct; Centered; Circular Tube
