ADS无窗散裂靶铅铋合金两相流动过程模拟

Flow and Phase Change Process of LBE Liquid and Vapor in the ADS Windowless Spallation Target

本文基于欧洲最新的无窗散裂靶几何结构，对铅铋合金的液体及蒸汽两相含气蚀相变的流动过程进行数值模拟和理论分析。采用路一￡湍流模型和VOF界面捕获算法模拟了水一空气靶的两相流动，并与同靶型实验结果进行了比较，两者吻合较好。通过计算不同出口压强的相界面形状，获得由于低压带来的气蚀相变及对最终界面形状的影响，结果还表明20000-28000Pa左右的出口压强可维持两个相界面，流动较稳定。运用伯努利方程理论推导出碰撞点上方回流区高度的解析表达式，并与计算结果进行比较，符合较好。上述物理结果对设计我国加速器驱动次临界堆无窗散裂靶具有一定参考价值。

Based on the latest structure of the European ADS windowless spallation target, the flow and cavitation phase change process of the lead-bismuth eutectic （LBE） liquid and vapor are numerically simulated and theoretically analyzed. The k -c turbulence model, VOF method and cavitation model are employed to simulate the flow of water and air and the results coincide with experiment very well. The steady-state phase distribution of the LBE liquid and vapor varies with different outlet pressure and the two phase change interfaces can be kept under the pressure of 20000~28000 Pa. The formula of the height of the recirculation region is deduced based on the Bernoulli＇s equation and fits well with the simulation. The conclusions of the present study are very important in the design and optimization of ADS windowless spallation target.