Simultaneous measurement of droplet size and velocity in nozzle sprays

This is the description of the application of a new LDA-method which simultaneously measures the size and velocity of small water droplets in the spray cone of a fan-type water nozzle. The phase difference between adjacent photomultipliers responding to signals from a fringe mode LDA is linearly proportional to the diameter of the spherical particle, so that, for long distances between the optical devices and the measuring volume in the spray, noninvasive and simultaneous measurements allow the correlation of size and velocity of the individual droplet in order to establish two-dimensional distribution.