Heat Transfer by Radiation and Other Transport Mechanisms : 3 rd Report, the Entrance Region of a Flow between Parallel Flat Plates with Simultaneous Radiation and Convection

抄録

Consideration is given to heat transfer for the problem of simultaneous development of velocity and temperature profiles in the case of a laminar flow in the entrance region between two flat plates. The duct consists of two diffuse, black, isothermal parallel surfaces separated by a finite distance. A medium filling the space between plates emits and absorbs thermal radiation. Numerical solutions are obtained for a slug flow (P_r=0), a flow of the inlet region (P_r=1) and a fully developed flow that was shown in the 2nd report, and show the influence of parameters such as the optical thickness, the ratio of conductive energy to radiative energy and Graetz number on the temperature variation across the duct and the heat transfer rates. The radiative heat transfer rate is scarcely affected but the convective one is much affected by flow patterns. An approximate method for the prediction of heat transfer rates in any flow patterns is shown and the results are in good agreement with the exact ones in the region of large optical thickness.