Numerical Simulation of Casting Filling Process Based on SPH-FEM Coupling Method

The coordinated optimization of free-surface dynamics tracking and solid deformation computation remains a persistent challenge in casting filling simulations. While the traditional smoothed particle hydrodynamics (SPH) method suffers from prohibitive computational costs limiting practical applications, the delayed interface updates of the finite element method (FEM) compromise simulation fidelity. This study proposes a symmetric SPH-FEM coupling algorithm that integrates real-time particle-grid data exchange, and validation through ring filling simulations demonstrated close agreement with Schmid’s benchmark experiments, confirming flow field reconstruction reliability. Furthermore, bottom-injection plate experiments verified the method’s thermal modeling stability, achieving fully coupled flow–thermal–stress simulations with enhanced computational efficiency. The proposed symmetric coupling framework achieves engineering-ready simulation speeds without compromising accuracy, and this advancement establishes a novel computational tool for predicting casting defects including porosity and hot tears, significantly advancing the implementation of high-fidelity numerical simulation in foundry engineering applications.