Monte Carlo - Surface "spots"??

tsimon

Hi, When using the MC radiation model, modeling heat exchange by radiation between the walls, at different Temperatures. of a cubic box (ex.) with air, considered transparent - so using s-t-s radiation, the solution has no physical meaning. A series of "spots" or "points" of different temperature appear when seeing result wall temperatures. If using the DTM, the result has now physical meaning and seems to be correct. "All" parameters are the same except, of course, number of histories (tried till some million with the same error) for MC or number of rays for DTM.

Could anyone tell me what am I missing when using the MC model, some additional boundary definition??? Do I need a solid domain when using MC?? ´ Thanks, tsimon