RADIATIVE HEAT TRANSFER IN COMPLEX ENCLOSURES USING NVD DIFFERENCING SCHEMES OF THE FTn FINITE VOLUME METHOD

摘要

In the present work, nine high-order resolution schemes based on the Normalized Variable Diagram (NVD) formulation, such as MINMOD, GAMMA, CLAM, NOTABLE, MUSCL, CUBISTA, SMART, WACEB, and VANOS schemes, are applied to the FTn FVM, a nonuniform angular discretization, for solving the radiative transfer equation in 2D and 3D regular and irregular enclosures containing transparent, emitting-absorbing, emitting-absorbing-scattering, and non-homogeneous media. To treat irregular boundaries, the blocked-off-region procedure is implemented. By comparing with analytical or numerical reference solutions, it should be pointed out that although all NVD schemes are much more accurate than the STEP scheme, they consume more time and require more iterations. Moreover, most of them oft en necessitate underrelaxation to ensure convergence. The MINMOD and GAMMA schemes are still much less accurate than other NVD schemes, but they converge most quickly of the NVD schemes, and do not require underrelaxation. Although the VANOS scheme gives more accurate solutions, it is not competitive with other NVD schemes.