Progress on coarse-mesh solidification modeling through an upscaling physics-based data-driven calibration

This research explores a fine-to-coarse mesh upscaling strategy for modeling solidification under turbulent flow conditions, with a specific focus on molten salt flows relevant to Generation-IV nuclear reactors. We propose modifications to the baseline solidification enthalpy–porosity coarse-mesh model employing a physics-informed approach that requires calibration from a high-resolution model. A data-driven approach is employed to calibrate the proposed model's coefficients using fine-mesh data obtained from a validated CFD RANS solidification model. The performance of the new solidification coarse-mesh model is assessed for turbulent forced flow regimes with varying degrees of overcooling. In comparison to the resolved fine-mesh model, the trained coarse-mesh model significantly reduces computational time, demonstrating promising results in predicting various parameters such as pressure drop, velocity profiles, temperature profiles, outlet temperatures, and solid thickness distribution within the domain.