Influence of Micro Ribs Segment on Quasi-periodic Large-scale Vortex Structure in 4 Rod Bundle Lattices

Abstract

Abstract Rod bundle lattices play a crucial role in nuclear reactors, steam generators, and heat exchangers. The inclusion of quasi-periodic large-scale vortex structures (QLVS) can enhance flow mixing between the channels of the rod bundle and improve the lattice’s heat transfer capability. To study the impact of micro-rib segments on flow and heat transfer in the lattice, the Reynolds stress model (RSM) is utilized. Results reveal that the arrangement of micro-ribs on the rod bundle surface promotes the generation of QLVSs. These micro-rib segments modify the flow field within the lattice, thereby influencing the QLVS. The drag coefficient and heat transfer coefficient of the rod bundle lattice with micro-rib segments show a positive correlation with the length of these segments compared with the standard rod bundle lattice.