Application of the local estimation methods to calculate the radiant intensity of a high-temperature jet

The article describes the statistical algorithms for calculating scattered radiation by the Monte Carlo method. Emphasis is on calculating light scattering in a medium with distributed volumetric radiation sources, for which an object was chosen in the form of an axisymmetric gas volume simulating an aircraft engine jet with nonuniform temperature and concentration distributions of the scattering particles. The theory of three Monte Carlo algorithms and their implementation on a graphics processor are demonstrated: the direct method of tracking photon trajectories and methods based on expansion in a Neumann series of solutions to the direct and adjoint radiative transfer equations (local estimates), taking into account weight modifications and various scattering indicatrices. Visual comparison of the operation of the algorithms is facilitated by presenting the data as the functional of the radiation rate and the area of the radiating surface (radiant intensity).