Temperature measurements of binary droplets using three-color laser-induced fluorescence

Evaporation of multicomponent droplets is a critical problem in many engineering applications, for example spray combustion. Knowledge of droplet temperature is a key issue in understanding the highly complex heat and mass-transfer phenomena related to multicomponent droplet evaporation and combustion. In this work, optical diagnosis based on three color-laser-induced fluorescence was developed: the objective was to measure the temperature of binary droplets (ethanol and acetone mixtures), even when the composition varies with time. Demonstration on an overheated droplet stream of acetone–ethanol mixtures is described and the experimental data are compared with results from a numerical simulation based on the discrete-components model.