非構造メッシュを用いたラージ・エディ・シミュレーションに適した並列ふく射伝熱計算法(熱工学,内燃機関,動力など)

Abstract

A parallel calculation method for radiative heat transfer that is suitable for LES (Large Eddy Simulation) on unstructured mesh is proposed. It is based on a discrete transfer radiation model coupled with a coarse mesh generation technique. Each coarse cell is automatically generated by grouping of a certain number of cells used for fluid dynamics calculation. The number of cells in a group is called agglomeration ratio. Two thermal radiative heat transfer problems are solved for validation. One validation case is a three-dimensional L-shaped geometry problem. The results of heat flux obtained by the proposed radiation method agree well with the result of Sakami et al. Simulation speed of radiation is improved by a factor of 7.4 when the agglomeration ratio is 8. The other validation case is a high temperature (1420[K]) turbulent jet, which is solved by a LES code coupled with the proposed radiation method. Calculated temterature distributions agree well with experimental data if radiative heat transfer is taken account. The simulation speed is improved by a factor of 8 when the agglomeration ratio is 16. The temperature error caused by the cell grouping is less than 23[K].