A new way to calculate radiative intensity and solve radiative transfer equation through using the Monte Carlo method

Through using the Monte Carlo method to calculate the fraction distributions of the emission scattered within an emitting, absorbing and scattering gray medium with a vacuum or a cold black wall, a new solution for the angular distributions of radiative intensity in the medium is presented. The angular distributions of intensity in one or more points, or even everywhere, can be calculated from the given distributions of temperature and radiative properties in the medium without the requirement of radiative equilibrium. For the emitting, absorbing, isotropic scattering, parallel-plane, gray media, some important relationships between the new and the formal solutions of the radiative transfer equation are delivered. Validation results for the angular distributions of radiative intensity got for the medium with uniformly specified distributions of temperature and radiative property and optical thickness less than 2.0 demonstrate that the new solution agrees well with the formal solution in the same condition. The work presented in this paper extends the application of the common Monte Carlo methods. In the recent future, more complicated parallel-plane cases will be studied by the same idea, especially with different kinds of wall conditions and/or anisotropic scattering.