Measurement of Temperatures on In-Flight Water Droplets by Laser Induced Fluorescence Thermometry
Keyword(s):
This work presents the use of laser induced fluorescence for instantaneous temperature measurements of a 200μm diameter water droplets monodispersed stream traveling downward in a standard stagnant atmosphere. The droplets are doped with small concentrations of a natural fluorescence dye (Pyrene), and with a surfactant substance, cetyldimetylbenzylammoniumchloride (CDBAC) to improve the fluorescence emission. The rate of the two-band pyreme emission (excimer to monomer) is used to determine the temperature. The temperature distribution along the stream of droplets determined for different initial temperatures: (30°C, 40°C and 50°C) at the exit of the nozzle compared very favorably with numerical results.