Three-dimensional study of radiative transfer in a semitransparent anisotropic scattering medium by using the modified discrete transfer method.

The development of the modified discrete transfer method (MDT) in a three-dimensional rectangular configuration allowed us to simulate the thermal behaviour of a semi-transparent, grey, absorbing emitting and anisotropically scattering medium at the radiative equilibrium. An internal source distributes heat uniformly in the medium while the walls of the enclosure that surround it, opaque, grey, diffuse for emission and reflection, are submitted to prescribed temperatures. A linear Variation law of the temperature, as well as the scattered radiation intensity, within a grid cell associated with the direction set of the discrete ordinates method has been adapted. A grid close enough to each inner wall was necessary far a better estimation of the incident flux near the singularities of the considered system. These global improvements led to a new version of the stable MDT method, as accurate as the zonal method and as flexible as the discrete ordinates one.