Experimental research and numerical simulation of moving molten metal pool

Abstract

Plenty of numerical simulations were performed to analyze the Molten Core-Concrete Interaction (MCCI) phenomena since 1980s. However, uncertainties remain among thermal hydraulic codes. Thus, in order to avoid the effect of uncertainties due to the different empirical formulas and interfacial models, a new CFD code based on Moving Particle Semi-implicit (MPS) method was proposed to simulate the MCCI event in the literature. Validation of the heat transfer and phase-change models is still necessary to utilize MPS method for the MCCI modeling. In this study, a small-scale visualization experiment was conducted using melted hot u-alloy and solid transparent gel wax to acquire quantitative data for validating heat transfer and phase change models of MPS method. Comparison of the simulation and experimental results demonstrates good agreement on ablation behavior and deformation profile of the molten metal moving downwards by the phase change of wax. Additionally temperature evolution in time showed consistency with the thermocouple measurements. Obtained results suggest that MPS code have capacity to simulate the phase change and heat transfer mechanisms of moving molten metal pool which are important mechanisms for the MCCI event.

Investigation of the Outflow and Spreading-Solidification Behaviour of Stratified Molten Metal

“…In this study, the heat transfer model and phase change model were introduced based on previous works [34][35][36][37][38][39][40]. Heat transfer calculations are essential to simulate melting-solidification behaviour.…”

“…In this model, the viscosity was increased up to the immobilization solid fraction called the "critical solid fraction", and the viscosity was set as a constant value above the critical solid fraction to stop flowing. This empirical equation has been widely used to reproduce meltingsolidification behaviour [34][35][36][37][38][39][40]. However, it was suggested that the critical solid fraction for flowing is significantly affected by 1 the shear rate of the fluid, 2 the cooling ratio, and 3 the material characteristics [42,43].…”