Atomization modes for levitating emulsified droplets undergoing phase change

Rao, DCK and Basu, S (2020) Atomization modes for levitating emulsified droplets undergoing phase change. In: Experiments in Fluids, 61 (2).

	PDF exp_flu_61-2_2020.pdf - Published Version Restricted to Registered users only Download (8MB) | Request a copy
	Microsoft Word 348_2019_2873_MOESM1_ESM.docx - Published Supplemental Material Download (1MB)

Abstract

Abstract: We delineate and examine the distinct breakup modes of evaporating water-in-oil emulsion droplets under acoustic levitation. The emulsion droplets consist of decane/dodecane/tetradecane as oil, while the water concentration is varied from 10 to 30 (v/v). The droplets were heated under different laser irradiation intensities and were observed to exhibit three broad breakup mechanisms, viz., breakup through bubble growth, sheet breakup, and catastrophic breakup. The occurrence of these modes of the breakup is found to be primarily dependent on the volatility differential among the components. Early nucleation in water/decane emulsions results in the growth of vapor bubble, which is characterized by intricate patterns of wave propagation on the droplet surface. The formation of these patterns suggests that the short time scale and length scale of wave patterns is the manifestation of Faraday instability, triggered on the droplet surface by the acoustic field induced resonance. A sheet-like breakup, on the contrary, occurs predominantly in emulsions comprising of components with relatively high volatility difference (water/dodecane emulsions) due to the breakup of an indiscernible small sized bubble. Intense catastrophic breakup occurs for emulsions with significantly vast volatility difference (water/tetradecane emulsions) where the droplet undergoes prompt fragmentation into fine secondary droplets.

Item Type:	Journal Article
Publication:	Experiments in Fluids
Publisher:	Springer
Additional Information:	Copyright of this article belongs to Springer
Keywords:	Acoustic fields; Emulsification; Emulsions; Ostwald ripening; Wave propagation, Acoustic levitation; Breakup mechanisms; Emulsion droplets; Faraday instability; Irradiation intensity; Secondary droplets; Water concentrations; Water in oil emulsions, Drop breakup
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	14 Feb 2020 05:52
Last Modified:	14 Feb 2020 05:52
URI:	http://eprints.iisc.ac.in/id/eprint/64511

Actions (login required)

View Item