Effect of viscosity and surface tension on breakup and coalescence of bicomponent sprays

Davanlou, Ashkan and Lee, Joshua D. and Basu, Saptarshi and Kumar, Ranganathan (2015) Effect of viscosity and surface tension on breakup and coalescence of bicomponent sprays. In: CHEMICAL ENGINEERING SCIENCE, 131 . pp. 243-255.

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Abstract

This work deals with an experimental study of the breakup characteristics of liquids with different surface tension and viscosity from a hollow cone hydraulic injector nozzle induced by pressure-swirl. The experiments were conducted at Reynolds numbers Re-p=9500-23,000. The surface tension and viscosity of the surrogate fuels were altered from 72 to 30 mN/m and 1.1 to 1.6 mN s/m(2), respectively. High speed photography and Phase Doppler Particle Anemometry were utilized to study the atomization process. Velocity and drop size measurements of the spray using PDPA in both axial and radial directions indicate a dependency on surface tension. However, these effects are dominant only at low Reynolds numbers and are negligible at high Reynolds number. Downstream of the nozzle, coalescence of droplets due to collision was also found to be significant and the diameters were compared for different liquids. For viscous fluids up to 1.6 cP, the independent effects of viscosity and injection pressure are studied. In general, the spray cone angle increases with increase in pressure. At high pressures, an increase in viscosity leads to higher drop sizes following primary and secondary breakup compared to water. This study will extend our understanding of surrogate fuel film breakup and highlight the importance of long and short wavelength instabilities. (C) 2013 Elsevier Ltd. All rights reserved

Item Type:	Journal Article
Publication:	CHEMICAL ENGINEERING SCIENCE
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copy right for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Keywords:	Atomization; Multiphase flow; Pressure-swirl nozzle; Coalescence; Breakup; Phase Doppler Anemometry
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	15 Jun 2015 11:12
Last Modified:	15 Jun 2015 11:12
URI:	http://eprints.iisc.ac.in/id/eprint/51688

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