9412179 Bachalo This project will lead to the development of a novel diagnostic that can simultaneously measure the velocity, size, and temperature of individual droplets in spray flames, and measure the gas phase temperature filed surrounding burning droplets in addition to their velocity, size, and temperature in controlled experiments involving single droplets, streams, or arrays of droplets. There are no equivalent commercial instruments in the market today. The prototype instrument will be applied to the study of droplet interaction in the combustion of high grade and low grade fuels. the effects of various environmental effects such as chemical composition and temperature, and fluid dynamical effects such as turbulence and acoustic oscillations, on droplet heatup and vaporization will be experimentally studied. The transient heating/ignition of fuel droplets will also be studied.