Phenomenology of break-up modes in contact free externally heated nanoparticle laden fuel droplets

Pathak, Binita and Basu, Saptarshi (2016) Phenomenology of break-up modes in contact free externally heated nanoparticle laden fuel droplets. In: PHYSICS OF FLUIDS, 28 (12).

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Abstract

We study thermally induced atomization modes in contact free (acoustically levitated) nanoparticle laden fuel droplets. The initial droplet size, external heat supplied, and suspended particle concentration (wt. %) in droplets govern the stability criterion which ultimately determines the dominant mode of atomization. Pure fuel droplets exhibit two dominant modes of breakup namely primary and secondary. Primary modes are rather sporadic and normally do not involve shape oscillations. Secondary atomization however leads to severe shape deformations and catastrophic intense breakup of the droplets. The dominance of these modes has been quantified based on the external heat flux, dynamic variation of surface tension, acoustic pressure, and droplet size. Addition of particles alters the regimes of the primary and secondary atomization and introduces bubble induced boiling and bursting. We analyze this new mode of atomization and estimate the time scale of bubble growth up to the point of bursting using energy balance to determine the criterion suitable for parent droplet rupture. All the three different modes of breakup have been well identified in a regime map determined in terms of Weber number and the heat utilization rate which is defined as the energy utilized for transient heating, vaporization, and boiling in droplets. Published by AIP Publishing.

Item Type:	Journal Article
Publication:	PHYSICS OF FLUIDS
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	17 Feb 2017 07:37
Last Modified:	17 Feb 2017 07:37
URI:	http://eprints.iisc.ac.in/id/eprint/56257

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