Temperature Measurements of Falling Droplets

Abstract

The temperature of 225-μm-dia decane droplets, which have fallen 100 mm through a hot quiescent, oxygen-free environment, has been measured using exciplex fluorescence thermometry. The droplets were doped with pyrene, and the relative intensities of pyrene monomer and excimer emissions were used to determine the droplet temperatures. The droplet temperature increases approximately 0.4°C per °C increase in the ambient temperature up to an ambient temperature of 200°C. Less than 10 percent evaporation was observed for the droplets at the highest ambient temperatures.