An Approximate Method for Multidimensional Problems of Radiative Energy Transfer in an Absorbing and Emitting Media

A new approximate method for dealing with radiant energy transfer in an absorbing and emitting media is presented. The approximate equations reduce to the correct optically thin and thick limits for multidimensional problems. The technique is used to predict the heat transfer between plane parallel plates and between concentric cylinders for a gray medium in radiation equilibrium. The results are in excellent agreement with previously published numerical solutions for all values of the optical thickness.