气泡在自由液面破碎后的射流断裂现象研究

Jet splitting after bubble breakup at the free surface

在势流假设下,考虑表面张力以及黏性修正,建立自由液面在气泡破碎后全非线性运动的数值模型,给出射流断裂和水滴撕裂的数值处理方法.同时进行上浮气泡在自由液面破裂的实验研究,数值解与实验值符合良好.为了研究自由液面在气泡破碎后的运动学机理和规律,运用开发的程序研究了不同尺寸气泡破碎后的动态特性,包括从气泡底部顶起的射流、射流断裂以及水滴分裂等复杂的物理现象,总结了从射流上撕裂出的第一个水滴尺寸、撕裂时间以及最大射流速度的变化规律.最后讨论了雷诺数与韦伯数对气泡破碎后自由液面运动的影响.

Under potential flow assumption, a numerical method is established to simulate the nonlinear movement of the free surface after the breakup of a bubble, with taking the surface tension and viscous into consideration. A method to handle the splitting of the jet or drop is put forward. Besides, an experiment of rising bubble bursting at the free surface is conducted, and the numerical result is in good agreement with the experimental result. In order to study the mechanism and law of the free surface movement after bubble breakup, the dynamic behavior of different sizes of bubble breakup is studied with the program developed, including the jet from the bottom of the bubble, the splitting of the jet or drop and so on. The variation law of the size and time of the first splitting drop, and the maximum velocity of the jet is studied and summarized. Finally, the influences of Reynolds number and Weber number on the free surface after bubble breakup are also analyzed.