计算物理 ›› 2021, Vol. 38 ›› Issue (6): 661-671.DOI: 10.19596/j.cnki.1001-246x.8332

• 研究论文 • 上一篇    下一篇

垂直排液过程不稳定性的数值模拟

肖寒, 李春曦, 苏浩哲, 叶学民()   

  1. 华北电力大学能源动力与机械工程学院, 河北 保定 071003
  • 收稿日期:2021-01-18 出版日期:2021-11-25 发布日期:2022-04-27
  • 通讯作者: 叶学民
  • 作者简介:肖寒(1996-), 男, 硕士研究生, 主要从事流体力学理论研究
  • 基金资助:
    国家自然基金项目(5187605);河北省自然科学基金项目(A2015502058)

Numerical Simulation on Instability of Vertical Liquid Drainage

Han XIAO, Chunxi LI, Haozhe SU, Xuemin YE()   

  1. School of Energy Power and Mechanical Engineering, North China Electric Power University, Baoding, Hebei 071003, China
  • Received:2021-01-18 Online:2021-11-25 Published:2022-04-27
  • Contact: Xuemin YE

摘要:

为分析线框排液实验中液膜表面出现的不稳定现象及其成因,针对含有不溶性活性剂的线框液膜排液过程,模拟液膜底部的不稳定现象,分析Marangoni效应、膨胀黏性和扰动波数因素的影响。结果表明:底部扰动在排液开始比较剧烈,而后快速减弱,到排液后期又逐渐增强。排液开始的扰动是由初始扰动引起,而排液后期的扰动与活性剂分布有关。较弱的Marangoni效应可增强表面扰动,而较强的Marangoni效应则减弱底部扰动,使液膜呈刚性,发生表面逆流现象;较高的膨胀黏性减慢液膜排液进程,降低表面速度,且能抑制Marangoni效应引起的逆流现象;波数较大的扰动使液膜在排液初期的扰动变强,但对排液后期的稳定性不产生影响。

关键词: 线框排液, 扰动, Marangoni效应, 膨胀黏性

Abstract:

To analyze instability on surface of liquid film in a wire-frame drainage experiment, we establish a three-dimensional mathematical model for drainage process of a wire-frame containing insoluble surfactants, and simulate instability at bottom of the liquid film. Influence of factors including Marangoni effect, dilational viscosity and disturbance wave number are analyzed. It shows that bottom perturbation is severe at beginning of drainage, then quickly weakens, and gradually increases in the late drainage. Perturbation at the beginning is caused by initial perturbation, and instability at the late of the drainage is related to the distribution of surfactant. A weaker Marangoni effect enhances the surface disturbance, while a stronger Marangoni effect inhibits the bottom perturbation, making the liquid film rigid and causing surface countercurrent. Higher dilational viscosity slows down the drainage process and reduces the surface velocity. It suppresses the countercurrent phenomenon caused by the Marangoni effect. A greater disturbance wave number makes the perturbation stronger in the early stage of drainage, while it does not affect the stability of late stage of the drainage.

Key words: wire-frame drainage, perturbation, Marangoni effect, dilational viscosity

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