A Coupled Numerical Scheme for Simulating Liquid Metal Cooling Process in the Production of Superalloys

The constant evolution of computer-aided engineering techniques continues to enhance our understanding of the liquid metal cooling process. Conventional methodologies often rely on fixed heat exchange coefficients for computing the thermal interaction between casting modules and the liquid coolant. This paper introduces a novel coupled numerical scheme integrating computational fluid dynamics (CFD) and solidification analysis. Within this framework, the commercial software ANSYS Fluent® addresses the CFD aspect of the coolant, while the ProCAST® handles the solidification simulation. The solidification process is simulated through solving heat conduction equation in which the heat flux boundary condition on the external surface of the cast module is determined according to the convective coolant flow. The CFD simulation based on the Navier–Stokes equations furnishes the heat flux at the module-coolant interface, taking the temperature field of the cast module as input. The coupled method is validated first with a test case in which a module is immersed inside coolant, followed by a multiphase flow simulation, wherein a casting module is pulled into the liquid tin bath from a gas-phase position. Both simulations reveal temperature variations in the coolant. Comparison with conventional heat exchange coefficient approaches confirms the influence of these variations on cooling curves. The coupled model is further used to investigate the effect of withdrawal rates on the solidification process, exhibiting qualitative agreement with experiments.