Note on particle size measurements in two-phase flows

This paper discusses the use of a phase-Doppler anemometer to obtain the size and velocity characteristics of droplets formed and transported in a flashing water jet. In particular, the validation and calibration procedures adopted to ensure correct acquisition of experimental data are discussed in detail. The methodology involved in choosing the magnitudes of the various operating parameters of a phase-Doppler anemometer such as the intensity of the transmitting beams, signal-to-noise ratio, sample size, and sensitivity of the photomultiplier tubes are described. The droplet size and velocity distributions were acquired at two axial stations covering the width and height of the jet cross-section. Attempts were made to identify the proper scaling variables to develop suitable nondimensional parameters to characterize a flashing jet.