Effect Of Viscosity And Surface Tension On Breakup And Coalescence Of Bicomponent Sprays

Keywords

Atomization; Breakup; Coalescence; Multiphase flow; Phase Doppler Anemometry; Pressure-swirl nozzle

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 Rep=9500-23,000. The surface tension and viscosity of the surrogate fuels were altered from 72 to 30mN/m and 1.1 to 1.6mNs/m2, 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 1.6cP, 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.

Publication Date

7-8-2015

Publication Title

Chemical Engineering Science

Volume

131

Number of Pages

243-255

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1016/j.ces.2015.03.057

Socpus ID

84928338229 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84928338229

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