Homogenization of the equations of radiative heat transfer through the corner

The paper discusses the possibility of averaging over the angle of radiation equations of the heat transfer for the problem of calculating the radiation field for the case of «flat» symmetry. In this case it is possible to move from relationship between vectors to the relations between the scalars values, which greatly simplifies the problem. From the comparison of the expansion with obtained approximations it follows that the diffusion approximation and the approximation of radiative heat transfer correspond to the linear approximation of temperature with respect to the small parameter.