基于扩散界面法的液态铅铋合金中气泡上升行为模拟

Numerical Simulation on Bubble Rising Behavior in Liquid Lead-bismuth Alloy Based on Diffuse-interface Method

基于扩散界面法,对单个氮气气泡在液态铅铋合金内从静止到充分发展整个过程中的动力学行为进行数值模拟,得到气泡形变特性和气泡上升速度随时间的变化关系,将模拟结果与Grace经验关系图对比,发现模拟得到的气泡形变结果在Grace经验关系图中均可找到且很好地吻合,从而验证了扩散界面法在模拟液态铅铋合金中气泡上升行为的可行性和准确性。同时基于界面扩散法的模拟,对比了5种不同初始直径的氮气泡在液态铅铋合金中的上升行为,发现初始直径较小的气泡在上升过程中扰动会更剧烈,初始直径较大的气泡在上升过程中易发生分裂现象。

The numerical simulation of a single nitrogen bubble in liquid lead-bismuth alloy（LBE）from static to the full development of dynamic behavior based on diffuseinterface method was done to get the relationship of deformation and rising velocity of the bubble by time.Comparing results of simulation of the flow characteristics about inert gas and liquid LBE with Grace＇s graphical correlation,it is found that deformation of the bubble is consistent with Grace＇s graphical correlation,which verifies the feasibility and the accuracy of diffuse-interface method on simulation of rising bubble＇s behavior in liquid LBE.By comparing rising behaviors of five different initial diameters of nitrogen bubble in liquid LBE based on diffuse-interface method,it is found that the smaller bubble initial diameter is,the disturbance will be more intense in the rising process,and the larger the bubble initial diameter is,the splitting phenomenon occursmore easily in the rising process.