Diagnostic Development for Characterizing Fuel Droplet Temperatures in Spray Flames

Development of efficient spray combustors requires a complete understanding of fundamental phenomena that influence and control the overall spray combustion process. Toward this end, detailed experimental characterization of spray flames is essential. This includes measurement of various fuel droplet parameters such as droplet size, velocity, number density, temperature, composition, and droplet vaporization rates in spray flames. The availability of the phase Doppler instrument has permitted simultaneous measurement of droplet size, velocity, and number density of fuel droplets in spray flames. However, the measurement of individual fuel droplet temperatures not been possible thus far. This proposal deals with diagnostic development for droplet temperature measurement in addition to droplet size and velocity in spray flames. The diagnostic instruments consists of rainbow refractometer which is fully integrated to a phase Doppler particle analyzer. The droplet size and velocity is measured with the phase Doppler particle analyzer and the droplet refractive index is measured with the rainbow refractometer. Sbusequently, the fuel droplet temperature is inferred from the droplet refractive index using a known relationship between the variation of the fuel refractive index with temperature. Various innovative techniques have been proposed to minimize errors resulting from droplet inhomogeneity and for increasing the measurement accuracy.