局部沸腾液滴内部气泡动态行为研究  

Study on Bubble Dynamics Inside Droplets Under Local Boiling

作　　者：胡定华[1] 邱晗 李强[1] HU Ding-Hua;QIU Han;LI Qiang(MIT Key Laboratory of Thermal Control of Electronic Equipment,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学电子设备热控制工信部重点实验室,南京210094

出　　处：《工程热物理学报》2021年第4期1026-1031,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金青年基金(No.51706102);中央高校基本科研业务费专项资金资助项目(No.30917011325)。

摘　　要：本文采用微加热器对液滴进行局部加热,并对其蒸发沸腾现象进行了可视化研究。液滴局部加热后产生局部沸腾现象,内部生成单气泡,气泡附着在加热基板上,持续生长,当达到某个临界点气泡破裂。在加热初期,气泡生长速度很快,随着加热过程的不断进行,气泡的生长速度逐渐放缓;随着气泡生长顺序的不断推迟,最大直径减小;加热功率的提升会增加气泡的生长速度,缩短气泡的生长时间。通过对气泡破裂过程的研究,气泡破碎过程开始于气泡上方的液膜断裂,形成不稳定的瑞利流和向上喷射的液滴,在表面张力的作用下,恢复初始状态,气泡破裂直径大小会影响液滴的波动幅度与周期。In this paper,the droplet is heated locally by a microheater,and its evaporation and boiling process is observed and recorded.While the droplet is heated locally,a single bubble is formed inside.The bubble adheres to the heating substrate and continues to grow until it reaches a certain critical point and bursts.In the early stage of heating,the bubble growth rate is very fast.With the continuous heating process,the bubble growth rate gradually slows down.The maximum diameter decreases with the delay of bubble growth sequence.The increase of heating power will increase the bubble growth rate and shorten the bubble growth time.Through the study on the process of bubble breaking,the process of bubble breaking begins with the rupture of the liquid film above the bubble,forming an unstable Rayleigh flow and the upwelling droplets.Under the action of the surface tension,the initial state is restored.The diameter of bubble breaking will affect droplet fluctuation amplitude and period.

关 键 词：液滴 单气泡 局部加热 沸腾 微型加热器 

分 类 号：TK124[动力工程及工程热物理—工程热物理]