Radiation heat transfer between arbitrary three-dimensional bodies with specular and diffuse surfaces

A numerical method is presented for predicting radiation heal transfer from arbitrary bodies composed of numerous polygons. Each polygon is gray and has the combined characteristics of specular and diffuse surfaces. Both heal flux and temperature can be specified arbitrarily on the surfaces. A new concept of view factors was introduced for analyzing radiation heat transfer between specular and diffuse surfaces. A radiation ray tracing method was adopted for estimating the view factors, and efficient vector operation and parallel processing were achieved for a supercomputer. The accuracy of the method was checked in comparison with analytical solutions for a simple configuration, and the effect of specular reflectivity was investigated. As a numerical example, radiation heat transfer of a machine element and heater panels composed of 4388 polygons was demonstrated.