乙醇液滴冲击过冷水平壁面的铺展行为实验研究  

Spreading Behavior of an Ethanol Droplet Impacts on a Supercooled Substrate

作　　者：张泽[1,2] 杨松[1] 刘秀芳 赖天伟[1,2] 侯予[1,2] ZHANG Ze;YANG Song;LIU Xiufang;LAI Tianwei;HOU Yu(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;MOE Key Laboratory of Cryogenic Technology and Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049 [2]西安交通大学深低温技术与装备教育部重点实验室,西安710049

出　　处：《西安交通大学学报》2024年第1期119-125,共7页Journal of Xi'an Jiaotong University

基　　金：国家科技重大专项资助项目(J2019-Ⅲ-0010-0054);国家自然科学基金资助项目(52076164);陕西高校青年创新团队资助项目。

摘　　要：为探究表面张力对液滴冲击过冷水平壁面铺展动力学行为的影响,搭建了可视化实验系统,探究了乙醇液滴冲击过冷水平壁面的铺展动力学行为,分析了水平壁面过冷度对低表面张力液滴冲击铺展动力学行为的影响。实验中,采用亲水硅水平壁面及较小的冲击速度以观测乙醇液滴冲击过冷水平壁面的铺展动力学行为。此外,还比较了不同的最大铺展因子和最大铺展时间的典型模型对乙醇液滴冲击过冷水平壁面铺展动力学因子的适用性。结果表明:乙醇液滴冲击过冷亲水水平壁面的铺展动力学行为分为飞溅、铺展、稳定3个阶段;最大铺展时间随水平壁面过冷度的增大而减小;水平壁面过冷度对最大铺展因子的影响是非单调的,在水平壁面过冷度较低时,最大内部铺展因子减小起主要作用,在水平壁面过冷度较高时,由于瑞利-泰勒不稳定性的增强,无量纲手指状突起增大起主要作用,二者共同作用造成了非单调变化;现有模型对于最大铺展时间的预测效果较好,相对平均偏差为6.05%,而对最大铺展因子的预测效果较差。This study aims to investigate the effect of surface tension on the spreading dynamics of a droplet impacting a supercooled substrate.To accomplish this,a visualization experimental system is established.The influence of substrate supercooling on the spreading dynamics of low surface tension droplet is analyzed.In the experiment,hydrophilic silicon substrate and a smaller impact velocity are used to observe the spreading dynamics of an ethanol droplet impacting the supercooled substrate.In addition,this study compares the applicability of typical models with different maximum spreading factor and maximum spreading time to the spreading dynamic factors of an ethanol droplet impacting supercooled substrate.The results demonstrate that the spreading dynamics of an ethanol droplet impacting the supercooled hydrophilic substrate can be divided into three stages:splash,spreading,and stability.The maximum spreading time decreases with an increase in substrate supercooling.Moreover,the influence of substrate supercooling on the maximum spreading factor is non-monotonic.At low substrate supercooling,the reduction of the maximum internal spreading factor plays a dominant role.Conversely,at high substrate supercooling levels,the enhancement of Rayleigh-Taylor instability leads to an increase in the“fingering-like”protrusion of the infinite chain plays a major role.The combined effect of the two causes non-monotonic changes.The existing models have good predictive performance for the maximum spreading time,with a relative mean error of 6.05%.However,their predictive accuracy for the maximum spreading factor is poor.

关 键 词：液滴冲击 过冷水平壁面 表面张力 铺展动力学行为 

分 类 号：O353.4[理学—流体力学]