OPERATION CHARACTERISTICS OF VIBRATING-ORIFICE GENERATORS - THE COHERENCE LENGTH

The use of monosized droplet streams for the calibration and testing of optical particle sizing methods and their application to the study of basic phenomena in two-phase systems are discussed. Owing to their coherent structure - all the droplets have the same size spacing - such droplet streams are very useful tools for these applications. The droplets streams have been produced with a vibrating-orifice generator. Limitations and problems that occur during the operation of these generators are described. Special emphasis is laid on the problem of the loss of coherence with increasing distance from the exit of the generator, which sometimes restricts the application of the generator for certain purposes.