零重力点热源马兰戈尼FTM数值模拟

FTM Numerical Simulation of Point Heat Source in Marangoni Without Gravity

采用界面跟踪法FTM(Front-Tracking Method),研究点热源流场中由Marangoni效应引起的液滴运动。模拟不同的Marangoni(Ma)数下液滴的运动。研究发现液滴运动速度先迅速增大到稳定迁移速度,而后下降,在t=1.2时出现反转,速度随Ma数的增加而增加。液滴内部存在与Hill球涡相同的回流。随着Ma数的增大,Hill球涡进行分裂,且涡旋中心有轻微的移动。同时温度场末端拓扑结构出现两次分叉。第一次分叉出现在下临界Ma数,最低温度点由滞止点跳进液滴内部;第二次分叉出现在上临界Ma数,内部的壳型冷却区从中心点破裂,出现一个环面型冷却区。

Front-tracking method(FTM)is used to study droplet motion caused by Marangoni effect with a point heat source in the diagonal direction.Droplet motion at different Marangoni(Ma)numbers was simulated.It was found that the droplet velocity which decreases as Ma number increasing,increases rapidly to a stable migration velocity then decreases.However,it reverses at t=1.2,which increases as Ma number increasing.Whereupon,the vortex of Hill sphere split and the vortex center moved slightly.The same reflux exists in the droplet as in the Hill sphere vortex.With the increasing of Ma,end topology of temperature field bifurcates twice:The lowest temperature point jumps into the droplet from the stagnation point when occurs firstly in the lower critical Ma number;The inner shell cooling zone breaks from the central point when occurs secondly at upper,then forming toroidal cooling zone.