Droplet velocity dispersion device

A droplet velocity dispersion device (DVDD), which can measure the uniformity of a droplet stream injected into a high vacuum, was developed. Droplet streams are passed through light; a magnified shadow image is reflected to the detector; and the stream image is superimposed on a slit which is perpendicular to the stream. The DVDD converts each image to signals which represent the shape, size, and longitudinal spacing of the droplet stream. The instrument can measure velocity dispersion to an accuracy of one part in 10 to the 6th. In order to obtain an accurate representation of the droplet stream, the time response of the DVDD must be small; in addition, the slit width of the detector has to be the correct size to admit the proper light level. These parameters were determined and the device tested. The test results compare well with theory. The information obtained from the DVDD can be used to develop a liquid droplet radiator for space application.