APPLICATION OF RAINBOW THERMOMETRY TO THE STUDY OF FUEL DROPLET HEAT-UP AND EVAPORATION CHARACTERISTICS

Advanced, nonintrusive, laser-based diagnostics are being developed fo r simultaneously measuring the size, velocity, temperature, and instan taneous regression rates of vaporizing/burning fuel droplets in polydi sperse flow environments. The size and velocity of the droplets are me asured using a conventional phase Doppler particle analyzer (PDPA), an d the droplet temperatures are simultaneously measured with a rainbow thermometer. This integrated diagnostic has been applied to the study of fuel droplet heat-lip characteristics in a swirl-stabilized kerosen e spray flame. it has also been shown that a novel extension of rainbo w thermometry can be used additionally to extract the instantaneous dr oplet vaporization rate. The feasibility of measuring the instantaneou s regression rate has also been demonstrated using controlled experime nts with a vaporizing/burning stream of ethanol droplets.