RADIATIVE HEAT-TRANSFER IN FINITE CYLINDRICAL ENCLOSURES WITH NONHOMOGENEOUS PARTICIPATING MEDIA

Results of a numerical solution for radiative heat transfer in homogen eous and nonhomogeneous participating media are presented. The geometr y of interest is a finite axisymmetric cylindrical enclosure. The inte gral formulation for radiative transport is solved by the YIX method. A three-dimensional solution scheme is applied to two-dimensional axis ymmetric geometry to simplify kernel calculations and to avoid difficu lties associated with treating boundary conditions. As part of the eff ort to improve modeling capabilities for turbulent jet diffusion flame s, predicted distributions for flame temperature and soot volume fract ion are used to calculate radiative heat transfer from soot particles in such flames. It is shown that the nonhomogeneity of radiative prope rty has very significant effects. The peak value of the divergence of radiative heat flux could be underestimated by a factor of 7 if a mean homogeneous radiative property is used. Since recent studies have sho wn that scattering by soot agglomerates is significant in flames, the effect of magnitude of scattering is also investigated and found to be nonnegligible.