CFD validation with optimized mesh using benchmarking data of pebble-bed high-temperature reactor

Abstract In this study, a computational fluid dynamics (CFD) analysis conducted to predict the thermo-hydraulic performance of the HTR-10, which is an experimental pebble bed reactor (PBR). The PBR with a modular model with a realistic approach and finite volume method (FVM) instead of porous media is used to predict the distribution of the critical thermal-hydraulics parameters like temperature, pressure, velocity, and heat transfer coefficient (HTC) over the pebbles as well as the reactor core. In the simulation study, an optimized mesh used as a replacement of the large size mesh. The simulation results, for the boundary conditions such as coolant inlet and outlet temperatures, mass flow, and other thermal-hydraulics parameters, were validated with the data published by the IAEA benchmark document. This study demonstrates that the CFD analysis using an optimized mesh is capable of predicting the nature thermo-hydraulic behavior of PBR core, maintaining design safety limits like maximum fuel temperature, and coolant flows distribution.