正丁醇水溶液液滴的蒸发特性实验研究

Evaporation characteristics of n-butanol aqueous solution droplets

中文关键词: 去离子水  正丁醇水溶液  液滴  蒸发特性

英文关键词: deionized water  n-butanol aqueous solution  droplet  evaporation characteristics

中文摘要:

      液滴蒸发过程中伴随着复杂的流变过程,现有研究对此并没有充分统一的认识；自湿润流体是一种具有特殊的表面张力特性的二元流体,了解其蒸发传热特性对于揭示其强化传热机理十分重要。本文为了探究添加自湿润流体液滴的蒸发特性,采用液滴形状分析仪(DSA100)研究了不同温度(30℃、40℃、50℃、60℃)下铜底板上去离子水、正丁醇水溶液(质量分数为0.5%)液滴的蒸发特性。结果表明：加入少量正丁醇溶液并不影响去离子水液滴的蒸发模式,但在去离子水中加入正丁醇溶液增大了初始液滴的接触半径、减小了初始接触角度,在底板温度较低时增快了液滴蒸发平均速率,加剧了液滴蒸发过程中Marangoni流动的强度,可以达到强化换热的效果；随着底板温度的不断增加,正丁醇水溶液液滴的平衡接触角以及蒸发速率均与温度成正相关,符合液滴的基本蒸发模式。

英文摘要:

      The droplet evaporation process is accompanied by a complex flow change process, which is not fully understood in the existing studies. Self-wetting fluid is a binary fluid with special surface tension properties, and understanding its evaporative heat transfer characteristics is important to reveal its enhanced heat transfer mechanism. In order to explore the evaporation characteristics of self-wetting fluid droplets, the droplet shape analyzer (DSA100) was used to study the evaporation characteristics of droplets of ionized water and n-butanol aqueous solution (0.5% mass fraction) from copper bottom plate at different temperatures (30℃, 40℃, 50℃, 60℃). The results show that：Adding a small amount of n-butanol solution does not affect the evaporation mode of deionized water droplets. However, the addition of n-butanol solution to deionized water increased the contact radius of the initial droplets and decreased the initial contact Angle, increased the average evaporation rate of the droplets when the bottom temperature was low, and increased the intensity of Marangoni flow during droplet evaporation thus enhancing the heat transfer effect. With the increase of the substrate temperature, the average contact Angle and evaporation rate of n-butanol aqueous solution droplets are positively correlated with the temperature, which conforms to the basic evaporation model of droplets.