The research on coherent structure in 7-rod bundle lattice. (February 2019) - Xiao, Hongguang
Highlights: The coherent structure in the whole channel of the 7-rod bundle lattice was numerical simulated. The occurrence and the development of the coherent structure were presented. The performances of three different lattices which had different coherent structures were compared. The influences of corner channel and wall channel to the coherent structure in little lattice were analyzed. Abstract: The generation and development of coherent structure in 7-rod bundle lattice are researched by Unsteady Reynolds-Averaged Navier-Stokes (URANS) method with the Reynolds Stress Model (RSM). The influence of the coherent structure on the flow resistance and heat transfer coefficient is also analyzed. It is revealed that the coherent structure is helpful to improve the performance of lattice. Decreasing the pitch-to-diameter ( P/D ) or properly changing the shape of rod can contribute to the generation of coherent structure. The flow redistribution caused by corner channel has great influence to the coherent structure.