粘性流中气泡的界面跟踪模拟及动力学分析

发布时间：2018-06-22 15:34

  本文选题：上升气泡 + 界面跟踪法　； 参考：《应用力学学报》2016年01期

【摘要】：气泡在运动过程中的动力学特性与流场的压力分布密切相关。本文用界面跟踪法(Front-Tracking Method,FTM)对气泡界面及其形状进行数值计算,模拟了粘性流体中单气泡上升的界面形态,并与文献中的实验结果进行对比。结果表明,在同一数量级上的厄特沃什数OE、莫顿数OM形状变化规律基本一致,计算模型的正确性得到验证。对同轴两气泡上升过程进行计算,与VOF的模拟结果进行对比,FTM方法得出的气泡形态变化相同,界面更加清晰;进一步研究同轴两个气泡上升动力学特性,使用清晰的界面位置对应压力场进行分析,从压力的角度分析了其变形、速度变化。结果表明:上下两个气泡都有一个压力中心区域使得气泡运动速度大幅度变化,气泡因界面所处区域的压力梯度分布不均呈现出由球形-子弹状-椭圆形的形态变化;随着时间推移,两个相互作用的气泡间的相互作用力在减弱,逐渐融合。
[Abstract]:The dynamic characteristics of bubbles in the process of motion are closely related to the pressure distribution of the flow field. In this paper, the bubble interface and its shape are numerically calculated by Front-Tracking method (FTM). The surface morphology of a single bubble rising in viscous fluid is simulated and compared with the experimental results in literature. The results show that the shape changes of the Ertworth number OEand Morton number OM are basically the same at the same order of magnitude, and the correctness of the calculation model is verified. The rising process of coaxial two bubbles is calculated. Compared with the simulation results of VOF, the bubble morphology changes are the same and the interface is clearer. The deformation and velocity change of the interface are analyzed from the point of view of pressure by using the clear interface position corresponding to the pressure field. The results show that the velocity of the bubble changes greatly because of the pressure center of the upper and lower bubbles, and the velocity of the bubble varies from spherical to bullet-ellipse due to the uneven distribution of pressure gradient in the interfacial area. Over time, the interaction between the two interacting bubbles weakens and fuses.
【作者单位】： 南昌大学机电工程学院;
【基金】：国家自然科学基金(51310105027) 江西省自然科学基金(20151BAB202002)
【分类号】：O35
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本文编号：2053289