The Measurement of Droplet Size Distributions from Rotary Atomizers

Abstract

Various experimental techniques have been developed to recover droplet size distributions emitted from rotary atomizers. These techniques include both single line-of-sight measurements through the center of the spray cloud and volume weighted averaging from multiple passes through portions of the spray. Because the droplet size distribution of a spray is one of the most important inputs into aerial spray prediction models such as AgDRIFT®, a consistent, widely-accepted standard for rotary atomizers should be developed and implemented with regard to this measurement. No such standard currently exists. The present paper summarizes current measurement techniques and develops a simple computer model to predict droplet movement following emission from a rotary atomizer in a wind tunnel. Qualitative comparisons are made with available data to demonstrate the effects of single line-of-sight measurements and weighted averaging from multiple passes.