Author(s)

G. N. Lygidakis & I. K. Nikolos

Abstract

The development of a spatial/angular agglomeration multigrid methodology is reported for the acceleration of a parallel node-centered finite-volume algorithm, numerically predicting radiative heat transfer in tetrahedral or hybrid unstructured grids. For spatial agglomeration, a sequence of coarser meshes is constructed, by merging the adjacent control volumes on a topology-preserving framework. Similarly, for the angular agglomeration, coarser angular resolutions are generated with the fusion of the neighbouring solid control angles, deriving a new angular discretization with the quarter number of control angles. The multigrid accelerated numerical solution of the Radiative Transfer Equation (RTE) is achieved via the Full Approximation Scheme (FAS) in a V-Cycle process. The proposed algorithm has been validated against benchmark test cases, demonstrating its capability for improved computational performance, especially in problems with purely scattering media and/or reflecting surfaces. Keywords: radiative heat transfer, node-centered, finite-volume method, multigrid, spatial/angular agglomeration, 3D unstructured hybrid grids.

Keywords

radiative heat transfer, node-centered, finite-volume method, multigrid, spatial/angular agglomeration, 3D unstructured hybrid grids.