Some exact solutions for radiation view factors from spheres

Abstract

Based on a new formulation for radiative view factor from a sphere to a class of axisymmetric bodies, closedform expressions are developed for the radiation view factors from a sphere to the external surface of a coaxial cylinder and from a sphere to an intersecting coaxial disk. The numerical results of the view factors are presented graphically in a wide range of parameters. At a limiting condition, one of the present formulas leads to the view factor from an annular ring to a coaxial hemisphere. The results are compared with those obtained earlier based on the Monte Carlo technique.