水平微电极表面气泡生长过程Marangoni对流数值模拟  

Numerical simulation of Marangoni convection during bubble growth on horizontal microelectrode surface

作　　者：詹水清[1] 袁睿 黄雨捷 张伟[1] 王军锋[1] ZHAN Shuiqing;YUAN Rui;HUANG Yujie;ZHANG Wei;WANG Junfeng(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学能源与动力工程学院,江苏镇江212013

出　　处：《中南大学学报（自然科学版）》2022年第12期4711-4719,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51704126);江苏省自然科学基金资助项目(BK20170551)。

摘　　要：为探究气泡底部微液层结构对水平微电极表面单个氢气泡生长过程中Marangoni对流效应的影响,基于水平微电极电解水制氢实验数据,采用固定气泡直径的物理数学模型对连续多个气泡生长时刻的不同直径气泡周围的Marangoni对流效应进行了数值模拟。研究结果表明:电解液焦耳热量主要产生于气泡底部微液层内,微液层内温度较大,气液界面周围电解液温度较小;沿着气泡弧长方向,电解液温度逐渐降低,形成明显的气液界面温度梯度分布,促使电解液从气泡底部沿着气泡弧长方向流动,形成不稳定的Marangoni对流旋涡结构;沿着气泡弧长方向的Marangoni对流速度逐渐减小,电解液温度和Marangoni对流速度最大值分别出现在气泡接触点和气泡接触点附近的右上侧界面位置;气液界面Marangoni对流速度近似随着气泡直径增大而增大,但这种变化规律对于不同直径的气泡来说,体现在不同的气泡弧长区域范围内。Marangoni对流旋涡结构及演变规律与整个气泡生长周期不同时刻的气泡直径有密切关联。To investigate the effects of the microlayer structure under bubbles on the Marangoni convection effect during single bubble growth on horizontal microelectrode surface, the Marangoni convection effect around bubbles of different sizes within multiple growth time was numerically simulated by using the physical and mathematical model of a fixed bubble diameter based on water electrolysis experiment. The results show that the joule heat of electrolyte mainly comes from the microlayer under the bubble. The electrolyte temperature is higher in the microlayer and is lower around gas-liquid interface. The electrolyte temperature drops gradually along the bubble arc length direction. Thus, the temperature gradient distribution forms obviously, which will assist the electrolyte in flowing along the bubble arc length direction from the bubble bottom. Consequently, the unstable Marangoni convection vortex structure forms. The Marangoni convection velocity gradually decreases along the bubble arc length direction. The maximum electrolyte temperature and the maximum Marangoni convection velocity appear at the bubble contact point and its upper right-side position, respectively. The Marangoni convection velocity increases with the increase of the bubble diameter and this trend behaves differently in different area ranges of bubble arc length for different bubble sizes. Marangoni convection vortex structure and development are closely associated with the bubble sizes of multiple growth time in the entire bubble growth cycle.

关 键 词：微液层模型 Marangoni对流 水平微电极 气泡生长 数值模拟 

分 类 号：TK91[动力工程及工程热物理]