SPATIALLY RESOLVED DROPLET SIZE MEASUREMENTS.

The paper encompasses initial tests of a droplet sizing technique, providing spatially and temporally resolved measurements within a liquid spray from an air assist nozzle. The method utilizes laser interferometry. The primary size measurement is based upon the signal visibility; it is validated by the peak intensity of the scattered light. As the system is based on the Doppler effect, a single component of velocity is extracted concurrent with the size information. The size of the measurement volume is controlled with off-axis light collection. Beam splitting is accomplished with a rotating diffraction grating, allowing the signal to be frequency shifted. Measurements are compared directly to those of a standard diffraction based sizing system.