液体通流微小槽道内气泡动力学行为模拟  

Numerical simulation of gas bubble emerging from pore into liquid flow micro-channel

作　　者：周吉[1] 朱恂[1] 丁玉栋[1] 王宏[1] 廖强[1] 谢建[1] 

机构地区：[1]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

出　　处：《化工学报》2011年第10期2740-2746,共7页CIESC Journal

基　　金：国家自然科学基金项目(50876119);重庆市自然科学基金项目(CSTC,2009BB6212);教育部新世纪优秀人才支持计划项目(NCET-07-0912)~~

摘　　要：采用VOF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。The dynamic behavior of a gas bubble entering a liquid flow micro-channel through a pore with prescribed mass flow rate was simulated by using computational fluid dynamics in conjunction with a volume of fluid （VOF） method. Simulations of the processes of gas bubble emergence, growth, deformation and detachment were performed to explicitly track the evolution of the liquid-gas interface, and to characterize the dynamics of a gas bubble subjected to water flow in terms of departure volume, flow resistance coefficient, and gas coverage ratio. The effects of wettability of the wall where the bubble emerges from, water and air mass flow rates were discussed with a particular focus on the effect of the wettability of the bottom wall while the static contact angles of the other channel walls were set to 90~. The simulated results showed that the hydrophilic wall facilitated the departure of bubble while gas coverage ratio increased and dimensionless flow resistance coefficient decreased for hydrophobic wall. High water inlet mass flow rate resulted in an earlier departure and decreased departure volume of the bubble as well as low gas coverage ratio and flow resistance coefficient. It was found that increasing air mass flow rate led to earlier detachment of the bubble. However, higher air mass flow rate showed scarce influence on the dynamic behavior of the bubble once the Reynolds number of air was over 14.

关 键 词：气泡 VOF方法 小槽道 动力特性 数值模拟 

分 类 号：TM911.4[电气工程—电力电子与电力传动]