THE DISCRETE PHOTONS METHOD. 2. REGULAR AND NONRECRJLAR SETS OF DISCRETE DIRECTIONS, NUMERICAL RESULTS FOR TEST PROBLEMS

A.M. Bujko, Yu.A. Demeatyev, R.F. Mashinin, I.D. Sofronov, E.N. Tikhomirova, E.G. Vasina
VANT. Ser.: Mat. Mod. Fiz. Proc 1993. Вып.4. С. 15-21.

      The method is intended to solve three-dimensional time-dependent radiant heat transfer problems. Approximate equations describe locally thermodynamically equilibrium radiation with account of material absorption and Isotropic scattering. Spatial cubooctahedron mesh and two sets of discrete directions are used. Two test problems numerical solutions are given.
      The problem concerning plane wave travelling with constant speed was solved using regular set of 14 directions correlated with cubooctahedron cells. The numerical results are in good agreement with analytical solution of the problem for radiant heat conduction equation.
      The problem of radiation transfer within a spheric cavity puts high requirements to angular description accuracy. With regular discrete directions set the numerical solution reveals strong ray effects. With specially precalculated view factors using nonregular set of directions aimed at boundary cells the solution is free from ray effects.