Combined mixed convection and radiation heat transfer in rectangular ducts rotating about a parallel axis

Abstract

The study of combined heat transfer of convection and radiation in rectangular ducts rotating in a parallel mode was investigated numerically in detail. The coupled momentum and energy equations are solved by the DuFort–Frankel numerical scheme to examine the interactions of convection with radiation. The integro-differential radiative transfer equation is solved by the discrete ordinates method. Results are presented over a wide range of the governing parameters. The present results reveal that the rotational effect in a square duct is more significant than that in a rectangular one. The predictions also demonstrate that the radiation presents significant effects on the axial distributions of the total Nusselt number, Nu t, and tends to reduce the centrifugal-buoyancy effects. The effect of rotation on the Nu t is restricted in the entrance region, however, the radiation affects the heat transfer through out the channel. Additionally, the Nu t increases with the decrease in the conduction-to-radiation parameter N C.