CFD study on the bubble dynamics characteristics of water-cooled reactors based on AMR

Background: Computational Fluid Dynamics (CFD) is a crucial tool for analyzing bubble dynamics in water-cooled reactors. Current studies on gas-liquid two-phase flow in such reactors predominantly employ fixed grids, which require a large number of grid cells to ensure 3D simulation accuracy at the gas-liquid interface, leading to high computational resource demands. Purpose: This study aims to apply Adaptive Mesh Refinement (AMR) technology to reduce computational cost while maintaining accurate capture of bubble dynamics in 3D simulations of water-cooled reactors. Methods: The AMR technique, which dynamically adjusts grid density, was combined with the VOF (Volume of Fluid) model. Three-dimensional numerical simulations were performed on typical bubble motion and phase change scenarios. Results: The research findings demonstrate that the AMR technique can effectively reduce the overall number of grid cells while appropriately refining the mesh at the gas-liquid interface. This approach accurately captures the kinematic characteristics of bubbles. Conclusions: The AMR technique shows good applicability for three-dimensional simulation of single bubbles, as it can lower computational costs while ensuring accurate prediction of bubble motion behavior.