Modified finite volume method applied to radiative transfer in 2D complex geometries and graded index media

A modified finite volume method with unstructured triangular meshes is proposed to solve the RTE in 2D complex geometries and for graded index media. In such media, the RTE has an additional term corresponding to “angular redistribution”. This term is due to the change in the orientation of the direction of propagation for the radiation along curved optical paths. Some benchmark cases applied to a slab (1D) and a square cavity (2D) with linear and nonlinear refractive graded index are used to validate the new method. New results are presented for a disk with radial graded index.