The numerical simulation and analysis of turbulent flow behavior in 5 × 5 fuel rod bundle with split-type mixing vane

Abstract

In this research, the numerical simulation and analysis of flow behavior in 5 × 5 fuel rod bundle with consideration of spacer grid has been conducted. ANSYS FLUENT 19.0 with the consideration of the transition SST (Shear-Stress Transport) with SAS (Scale-Adaptive Simulation) turbulence model is used for the numerical simulation. The obtained simulation results are reasonable compared with the experimental data based on the comparison in the aspect of velocity distribution. The effect of the spacer grid on the flow behavior in the fuel rod bundle has also been investigated. The mixing vanes in the spacer grid can cause various strong flow branches; these flow branches develop and cause the complex flow behavior in the fuel rod bundle. Additionally, the secondary flow, the swirling factor and the mixing factor were investigated for the quantitative analysis of the spacer grid effect on the flow mixing behavior in fuel rod bundle.