An Experimental Investigation on Spreading of Droplets with Evaporation and Nucleation

摘要

An experimental investigation was conducted to visually observe the dynamic characteristics of water droplets with evaporation and nucleation on stainless steel and polished silicon surfaces. The water droplet diameter, contact area, and spreading speed were measured using a high-speed CCD camera at surface temperatures ranging from 110 ℃ to 190 ℃, and a model was proposed to describe the dynamic behavior of droplet spreading. The spreading of water droplets under evaporation and nucleate boiling is highly dependent on the dynamic bubble behavior in the droplets, particularly bubble volume, bubble interaction, as well as the surface properties and temperature. Water droplets were easiest to spread at the surface temperature of 130 ℃, and the spreading tendency increased with increasing surface coarseness.