平行微通道内气泡撞壁分裂行为数值模拟  

Numerical Simulation of Bubble Wall Collision Splitting Behavior in Parallel Microchannels

作　　者：董澳 方奕栋[1] 张昭 王雨晨 胡凌韧 DONG Ao;FANG Yidong;ZHANG Zhao;WANG Yuchen;HU Lingren(School of Energy and Power,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《制冷技术》2023年第1期1-6,10,共7页Chinese Journal of Refrigeration Technology

摘　　要：本文基于体积分数法(VOF)模型,对流动沸腾中气泡撞击加热肋面的过程进行了数值模拟,研究了不同流速和初始尺寸下气泡撞击行为对流动沸腾换热特性的影响。通道入口主流速度设为0.1 m/s和0.2 m/s,气泡无因次直径设为db*为1.6和2.0。结果表明,气泡在撞击过程中发生内凹,最终分裂为2个子气泡;在撞击时,气泡与撞击肋面端点处形成了薄液膜层,增强了蒸发效应,但同时使气泡更易破裂,从而造成局部干涸并形成高温;在较高流速下,气泡破裂现象会有所延迟,db*为1.6和2.0时,换热性能分别提高了2.57%和6.60%,较低流速下则分别减弱了25.98%和23.67%。Based on the volume of fluid(VOF)model,the process of bubble impacting the heated fin wall in flow boiling is numerically simulated,and the influence of bubble impact behavior on the flow boiling heat transfer performance with different flow velocity and initial bubble size are studied.The entrance velocity of the channel is set to 0.1 m/s and 0.2 m/s,and the dimensionless diameter(db*)of the bubble is 1.6 and 2.0.The results show that the bubble is concave during the impact and finally splits into two sub-bubbles.During the impact,a thin liquid film layer is formed between the bubble and the endpoint of the impact wall surface,which enhances the evaporation.Meanwhile,the bubble is also quite easy to rupture,causing local drying up and forming a high temperature.The rupture of the bubble can be delayed at higher flow velocity.When the db*is 1.6 and 2.0,the heat transfer performance can be increased by 2.57%and 6.60%respectively at higher velocity while decreased by 25.98%and 23.67%at lower velocity.

关 键 词：微通道 流动沸腾 气泡撞击行为 换热 

分 类 号：TB611[一般工业技术—制冷工程] TK124[动力工程及工程热物理—工程热物理]