采用理论分析和实验测量相结合的方法研究了水滴在玻璃基底上稳态蒸发时内部能量传输机制。发现了气-液、固-液界面温度不连续现象,且越靠近三相接触线,固-液界面温差越大。固-液界面吸附层的存在导致了该界面温度不连续,从玻璃基底导入的大部分热量通过界面吸附层传向三相接触线,然后通过热毛细对流被带向气液界面以满足液滴蒸发所需热量,而另外一小部分热量则直接通过导热进入液滴内部。
The mechanism of energy transport of water droplet evaporation on a silica substrate was experimentally investigated.The temperature fields in the solid substrate,the droplet and its vapor phase were measured.It was found that when a sessile droplet evaporates into its own vapor, the temperatures at the solid-liquid and liquid-vapor interfaces are discontinuous.Closer to the three-phase line,the temperature discontinuity becomes greater.At the solid-liquid interface,an adsorbed liquid layer is formed.From the energy transported by solid substrate to the solid-liquid interface,only a small portion is conducted to the bulk liquid phase;most of the energy is distributed by the thermocapillary convection and consumed by the phase change process.