Numerical study of fluid characteristics and freezing of liquid metal injection in a water pool

The main problem in the injection of a liquid metal in water is the jet breakup, due to Rayleigh-Plateau, Rayleigh-Taylor and Kelvin-Helmholtz instabilities. In the present study the characteristics of liquid metal jet are numerically investigated via Computational Fluid Dynamics (CFD) approach. CFD analysis is performed using a finite volume code with Volume-of-Fluid method for the jet interface tracking, and the injection is reproduced using a 2-D domain. The present study aims to develop a complete CFD model in order to better reproduce the physics of the sealing problem. In the first part, a fluid dynamics analysis is performed and the CFD model is validated using experimental data. The jet breakup is evaluated through the Jet length/Nozzle Diameter (L/D) parameter and the instability presence along the jet is correctly reproduced. In the second part, solidification model is introduced and thermal and freezing analysis is developed. Thermal field at different Weber number is studied and compared with experimental data. A preliminary analysis of metal solid debris is performed and results of characteristic dimensions are compared with available experimental data. In addition, typical dimensions of metal debris are compared with classical fragmentation theory. The complete CFD model is able to reproduce the physics of the sealing problem in a 2-D domain. On the other hand, further investigations are needed to study the accumulation and spreading of liquid metal over a plate.