上海交通大学学报

上海交通大学学报 ›› 2020, Vol. 54 ›› Issue (7): 728-735.doi: 10.16183/j.cnki.jsjtu.2019.211

• 学报（中文） • 上一篇    下一篇

变密度流体层中气泡浮升运动的数值模拟

李乾，楼映中，贺治国   

  1. 浙江大学 海洋学院；港口海岸与近海工程研究所，浙江 舟山 316021
  • 出版日期:2020-07-28 发布日期:2020-07-31
  • 通讯作者: 贺治国，男，教授，博士生导师；E-mail：hezhiguo@zju.edu.cn.
  • 作者简介:李乾（1996-），男，江西省九江市人，硕士生，主要从事计算流体力学方面的研究.
  • 基金资助:
    国家重点研发计划(2017YFC0405400)，中央高校基本科研业务费专项资金 (2017XZZX001-02A)资助项目

Numerical Simulation of a Rising Bubble in Variable-Density Fluids

LI Qian,LOU Yingzhong,HE Zhiguo   

  1. Ocean College； Institute of Port, Coastal and Offshore Engineering, Zhejiang University, Zhoushan 316021, Zhejiang, China
  • Online:2020-07-28 Published:2020-07-31

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摘要： 本文开发了一种耦合气体和两层不同密度液体的直接模拟数值模型，以研究变密度流体层中气泡浮升的运动特性.基于高精度空间离散的5阶加权本质无振荡格式和时间离散的3阶Runge-Kutta格式，提出一种多水平集函数耦合的数值方法，实现了气液相界面和各液体表面的捕捉以及交界面处密度和黏度的计算.模型用已有文献的计算结果进行了验证，并应用于水、油两层流体中气泡运动的研究，有效地捕捉了复杂条件下气泡浮升运动的精细结构.研究发现：相较于均匀密度流体层中的运动，气泡在变密度流体层中运动时，其下方的压差液柱更容易在底部发生断裂分离；气泡上方液体的厚度较大，则气泡处于水下变形阶段的时间就越长，并使气泡底部的形态更趋向于扁平.

关键词: 气泡, 变密度流体层, 水平集法, 数值模拟

Abstract: In this paper, a direct numerical simulation model coupled with gas and two layers of liquid with different densities is developed to study the dynamics of rising bubbles in a two-layer stratified environment. Based on the level set method with 5th-order weighted essentially non-oscillatory (WENO) and 3rd-order Runge-Kutta scheme, a numerical method coupling multiple level set functions is proposed to capture both the gas-liquid interface and each liquid surface, as well as calculating both the density and viscosity on the interface. The method proposed is verified by comparing with the available numerical simulation results. Besides, this model is employed to study the motion of a rising bubble in a two-layer fluid involving water and oil, which provides detailed flow structures in a complex environment. The results suggest that compared with the movement in a uniform environment, the water column induced by pressure difference is easier to break at the bottom when a bubble rises against a two-layer stratified background. The increase of liquid thickness above the bubble can extend the time that the bubble stays in the underwater deformation stage, and can lead to a flatter bottom of the bubble.

Key words: bubble, stratified fluids, level set method, numerical simulation

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