Radiation heat transfer of arbitrary 3-D participating media and surfaces using radiation element method by ray emission model (REM²)

A generalized numerical method for radiation heat transfer of absorbing, emitting and scattering media and specular and/or diffuse surfaces with three-dimensional arbitrary configurations, REM², is proposed. The ray emission model for various radiation elements is expressed by polyhedrons and polygons. Arbitrary thermal conditions can be specified for each radiation element, and generalized radiation transfer can be achieved regardless of surface and volume elements by introducing a new definition of view factors. The accuracy of the present method is verified using simple configurations. A cubic participating medium with a spherical cavity covered with specular and/or diffuse surfaces is analyzed as an example of an arbitrary configuration. The temperature distribution shows good accuracy in the case of a small number, such as 45, of rays emitted from each element compared with the Monte Carlo method.