Performance analysis of natural convection in presence of internal heating, strong turbulence and phase change

Abstract Experimental study and numerical simulation work were carried out to investigate the natural convection performance in presence of internal heating, strong turbulence and phase change. The experiments were performed in large-scale facility with two simulants for comparison: water without solidification and molten salt with solidification. Three heating power levels were conducted for each simulant, all with high Rayleigh numbers up to 1016. In addition, the simulation work with large eddy simulation was performed to obtain detail information inside melt pool. The distributions of temperature and velocity, as well as heat flux and crust characteristics were presented and compared from experiments and simulation. The distributions of temperature and heat flux presented increasing distribution and the crust showed the contrary trend. The non-uniform solidification will strengthen natural convection turbulence and heat transfer in the pool top region, which will finally increase the risk of vessel wall failure. This work could help to better understand the thermal and flow performance related to complicated natural convection behavior.