Andrew J. Yule
Spray Research Group (SRG), Insititute of Materials Research (IMR), School of Computing, Science and Engineering, University of Salford, Manchester, UK; Thermofluids Division, Department of Mechanical Engineering, UMIST
I. R. Widger
University of Manchester Institute of Science and Technology, UMIST Manchester, England
Abstract
High pressure swirl atomizers have been investigated experimentally. Their sprays, confined in tubes, are used as
air pumps for dust removal and methane dilution in mining and tunneling. An empirical approach is used to derive
an optimum atomizer goemetry for improved air-mover pumping using liquid flow rate, drop size, spray angle and
entrainment ratio data. A specially constructed patternometer shows spray maldistributions from atomizers
machined to high tolerances. Phase Doppler and Malvern drop size data are in good agreement and show the drop
size/velocity correlations are not strong at the point of measurement. Comparisons are made with previous
approaches to correlating swirl jet performance which are based on classical free-vortex theory. Some broad
agreement for Cd, drop diameter and spray angle is found although published equations overestimate the measured
drop size. A modified atomizer parameter of the form K(Ds/D0)1−n as given by Dombrowski and Hasson, best correlates measured Cd and 2θ when using 0.2≤n≤0.3. This and other observations indicate the existence of turbulent flow inside the high velocity atomizer flows.