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.

进行了实验研究和数值模拟工作，以研究内部加热，强湍流和相变存在时的自然对流性能。实验是在大型工厂中使用两种模拟物进行比较的：未固化的水和具有固化的熔融盐。对每个模拟物进行了三种加热功率级别，所有功率级别均具有高达10 ^16的高瑞利数。此外，还进行了具有大涡模拟的模拟工作，以获取熔池内部的详细信息。给出了温度和速度的分布，以及热通量和地壳的特征，并通过实验和仿真进行了比较。温度和热通量的分布呈现增加的分布，而地壳呈相反的趋势。不均匀的凝固将增强池顶区域的自然对流湍流和热传递，最终将增加容器壁失效的风险。这项工作可能有助于更好地了解与复杂的自然对流行为有关的热和流动性能。