液体通流微小槽道内气泡动力学行为模拟_周吉

　第62卷　第10期 化　工　学　报 V ol.62　N o.10　2011年10月 CIESC　Jo urnal Oc to be r　2011研究论文液体通流微小槽道内气泡动力学行为模拟

周　吉,朱　恂,丁玉栋,王　宏,廖　强,谢　建

(重庆大学低品位能源利用技术及系统教育部重点实验室,重庆大学工程热物理研究所,重庆400044)

摘要:采用VO F方法,对液体通流微小通道内壁面逸出气泡的形成、生长及脱离运动进行了数值模拟,并讨论

了壁面浸润性、液体流速、气体流速对气泡动力学行为的影响。结果表明:气泡生长壁面亲水性增强有利于其

从壁面脱离;气泡生长壁面气相覆盖率随壁面接触角的增大而增大;流动阻力因子随壁面接触角的增大而减小。

较高的液体流速会导致气泡的脱离时间和脱离体积、壁面气相覆盖率及流动阻力因子减小;而较高的气体逸出

速率(气相Reynolds数高于14时)对气泡脱离体积、壁面气相覆盖率和流动阻力因子影响不大。

关键词:气泡;VO F方法;小槽道;动力特性;数值模拟

D OI:10.3969/j.issn.0438-1157.2011.10.010

中图分类号:T M911.4 文献标志码:A文章编号:0438-1157(2011)10-2740-07

N um erical sim ula tion of gas bu bble e mergin g fro m pore in to liquid flo w micro-ch an n el

ZH OU Ji,ZHU Xu n,DING Yu dong,WAN G Hong,LIAO Qian g,XIE Jian

(K ey L aboratory o f Low-grade Energ y Utilization Technologies and Sy stems,

Institute o f Engineering Thermophysics,Chongqing University,Chongqing400044,China)

Abstract:The dynam ic behavio r o f a gas bubble entering a liquid flow micro-channel through a pore w ith prescribed mass flow rate w as simulated by using computational fluid dynamics in co njunctio n w ith a volume of fluid(VOF)method.Sim ulations of the processes of gas bubble emergence,g row th, defo rmatio n and detachm ent w ere performed to ex plicitly track the evolutio n of the liquid-gas interface, and to characte rize the dy namics o f a gas bubble subjected to w ater flow in terms of departure v olume, flo w resistance coefficient,and g as coverage ratio.The effects of w ettability of the w all w here the bubble eme rges fro m,w ater and air mass flow rates w ere discussed w ith a particular focus on the effect o f the wettability of the bo ttom w all w hile the static contact ang les of the o ther channel w alls w ere set to90°. The simulated results sho wed that the hy dro philic w all facilita ted the departure of bubble w hile g as cove rage ratio increased and dimensionle ss flow resistance coefficient decreased fo r hydrophobic w all.High w ater inlet mass flow rate resulted in an ea rlier departure and decreased departure vo lum e of the bubble as well as low gas coverage ratio and flow resistance coefficient.I t w as found that increasing air mass flo w rate led to earlie r detachm ent of the bubble.H ow eve r,hig her air m ass flow ra te show ed scarce influence on the dy namic behavior of the bubble o nce the Rey nolds number of air w as over14.

Key words:bubble;vo lume of fluid method;mini-channel;dynamics;numerical simulation

2011-01-10收到初稿,2011-04-28收到修改稿。

联系人:朱恂。第一作者:周吉(1986—),男。

基金项目:国家自然科学基金项目(50876119);重庆市自然科学基金项目(CS TC,2009BB6212);教育部新世纪优秀人才支持计划项目(NCE T-07-0912)。

Received date:2011-01-10.

Correspon ding author:Prof.ZH U Xun,zhu xun@

Foun dation item:supported by the National Natural S cience Foundation of China(50876119),the Natural S cience Foundation of Ch ong qin g(CS TC,2009BB6212)and th e Prog ram for New Century Excellent T alents in University(NCET-07-0912).