Cfd Prediction of Pressure Drop for the Inlet Region of a Pwr Fuel Assembly

Computational Fluid Dynamics (CFD) has been widely used in pressure drop/hydraulic loss calculations in many industries, including the aerospace and turbo-machinery industry as well as in the nuclear power industry. During the past 30 years, a significant amount of time and effort have been spent in benchmarking the CFD tools and models against test data in aerospace and turbo-machinery industry. The application of the CFD methods in the nuclear power industry is relatively new in comparison and has accelerated in recent years. This paper focuses on the benchmarking of the CFD modeling of Westinghouse fuel assemblies. The pressure drop across the fuel assembly is a very important characteristic to consider in the design of any new fuel assembly design. The ability to accurately predict the pressure drop across the fuel assembly is critical in nuclear fuel design. In this paper, the effect of the turbulence model in the CFD modeling is investigated. Different computational meshes are generated and evaluated. The results show that the turbulence model and mesh density both have a significant effect on the pressure drop predictions. A well calibrated modeling procedure is needed to meet the strict requirements of the nuclear power industry. This paper shows that a well calibrated CFD model shortens the design cycle and saves costs in the development of new fuel assembly components. Most importantly, it enables Westinghouse to more easily investigate new fuel assembly component designs, some of which were never thought possible before because of the involved development process.