Experimental study on the evaporation characteristics of Jatropha curcas oil methyl ester (JME)-ethanol blended droplets

Abstract

The evaporation and micro-explosion characteristics of Jatropha curcas oil methyl ester (JME) at 10%, 20%, and 30% ethanol by volume at two ambient temperatures were investigated using droplet evaporation experiments. The effects of different temperatures and ethanol content on parameters such as the normalized square diameter of droplets, micro-explosion intensity, number of micro-explosions, droplet evaporation duration and evaporation rate were analyzed. The experimental results show that adding ethanol component to the JME droplets increases the droplet expansion micro-explosion, and increasing ambient temperature promotes the droplet micro-explosion intensity and the number of micro-explosions. The intensity and number of micro-explosions of blended droplets are related to the concentration of ethanol. In addition, the micro-explosion intensity is numerically divided into strong micro-explosion and weak micro-explosion. Different concentrations of ethanol improve the evaporation characteristics of droplets differently. In general, the higher the concentration of ethanol, the shorter the droplet evaporation duration and the greater the evaporation rate. It was found that increasing the ethanol concentration from 20% to 30% had the most significant effect on droplet duration. Notably, the phenomenon of vapor clouds due to non-isothermal condensation caused by Stefan outflow was discovered.