Authors: Srikrishna Sahu Yannis Hardalupas Alex M K P Taylor
Publish Date: 2014/02/04
Volume: 55, Issue: 2, Pages: 1673-
Abstract
This paper presents a novel optical technique for simultaneous planar measurement of droplet and vapour phases in an evaporative spray The technique combines the outoffocus imaging technique ‘Interferometric Laser Imaging for Droplet Sizing’ ILIDS for planar simultaneous measurements of droplet size velocity and number density with the infocus technique ‘planar laserinduced fluorescence’ PLIF for measurements of vapour concentration around individual droplets As with the combined ILIDS and PIV technique Hardalupas et al in Exp Fluids 49417–434 2010 a discrepancy occurs in the location of the same droplet while imaging through both techniques The centre discrepancy is experimentally estimated and so the position of the droplet centres in the ILIDS image can be corrected which is essential for the measurement of the correlation of the local vapour concentration with its corresponding droplet size and velocity The combined technique is first applied to monosized acetone droplet stream for two droplet sizes which have different interdroplet distances A new method is proposed for the correction of the ‘halation’ effect around droplets on vapour fluorescence intensity around the monosized droplets in the PLIF image A phase discrimination method to separate droplet and vapour fluorescence in PLIF images of evaporative sprays is explained It is shown that the combined ILIDS and PLIF technique is an effective tool for studying group evaporation of droplets and interaction between the two phases in an evaporative spray
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