Calculation Model Research of Local Resistance Coefficient for Spacer Grids Based on CFD Methodology

In order to develop high-performance fuel assemblies, resistance characteristics of spacer grid are directly related to thermal performance and hydraulic compatibility of fuel assemblies. Based on basic principles of flow resistance, the calculation model of local resistance characteristics for 5×5 spacer grids was studied and built by using CFD method and the calculation results were validated. The results show that the local resistance coefficients from calculation model are generally in agreement with those from direct simulation.