Radiant and convective heat transfer for flow of a radiation gas in a heated/cooled tube with a grey wall

Abstract

An analytical investigation is presented of the influence of radiative heat transfer on the complex heat exchange problem involving flow of an optically active (radiating) gas inside a tube of diffuse grey properties. The method used is based on Hottel's formulation of zone division, and involves the transformation-zone approach, where radiation gas emission is replaced with an equivalent surface emission. Separable-kernel and surface transformation techniques give a set of non-linear differential equations treated by the Runge-Kutta method with Hamming modification. The solutions are governed by several independent parameters such as the wall and radiation gas emissivities, inlet and exit gas temperatures, length diameter ratio of the tube, uniform and non-uniform heat flux and variable convective heat transfer coefficient at the inner surface. The results apply both to heating and cooling situations.