水-乙醇液滴撞击加热面过程的可视化观测  

Visual Observation of Droplets of Water-Ethanol Mixture Impinging on Heating Surface

作　　者：李婧文 吴兴辉 段远源[1] 杨震[1] LI Jing-Wen;WU Xing-Hui;DUAN Yuan-Yuan;YANG Zhen(Key Laboratory for Thermal Science and Power Engineering of MOE, Tsinghua University, Beijing 100084, China)

机构地区：[1]清华大学热科学与动力工程教育部重点实验室

出　　处：《工程热物理学报》2019年第10期2220-2225,共6页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.51736005,No.51876101)

摘　　要：利用高速摄像仪对水-乙醇混合物液滴撞击加热表面的过程进行了可视化观测,探讨了流体物性、加热面温度、液滴撞击速度对该过程的影响,分析了液滴的形态变化以及在加热面铺展和沸腾的特征。结果表明液体的惯性力、黏性力和表面张力共同决定了液滴的铺展特性,实验中观测到了混合物液滴的回缩滞后和液滴在高温下的核态沸腾现象,发现黏性力、表面张力和组分分布共同影响液滴边缘液膜的回缩过程,温度的改变会影响液滴的相变特性.A high-speed camera was used to visually observe the process of water-ethanol mixture droplets impinging on heating surface.The effects of fluid properties,surface temperature and impact velocity were discussed,and the morphologic change,spreading and boiling characteristics of the droplets were analyzed in this paper.The results show that the inertial force,viscous force and surface tension of the fluid determine the spreading characteristics of the droplets.The hysteretic shrinkage of the mixture droplets and the nucleate boiling at high temperature were observed in the experiment.It was found that the viscous force,surface tension and composition distribution have a common influence on the shrinkage of the liquid film,and the change in temperature affects the phase transition characteristics of the droplets.

关 键 词：非共沸混合物 高速摄像 液滴撞击 沸腾 液滴铺展 

分 类 号：TK019[动力工程及工程热物理]