Criteria for thermally induced atomization and catastrophic breakup of acoustically levitated droplet

    Authors

    S. Basu; A. Saha;R. Kumar

    Comments

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    Abbreviated Journal Title

    Int. J. Heat Mass Transf.

    Keywords

    Instabilities; Bag breakup of droplets; Acoustic levitation; Atomization; FLOW; Thermodynamics; Engineering, Mechanical; Mechanics

    Abstract

    We report thermally induced instability leading to catastrophic breakup in acoustically levitated vaporizing fuel droplets. Change in surface tension and viscosity with increase in droplet temperature causes wide fluctuations in droplet aspect ratio. If the viscous damping of aspect ratio oscillation is not strong enough, the droplet goes through unbounded stretching. If the droplet exceeds a critical Weber number locally, a bag type and capillary wave induced atomization can occur, which leads to catastrophic breakup. A stability criterion has been established based on the inhomogeneity of Bernoulli (acoustic) pressure and surface tension of the droplet in terms of a local Weber number and Ohnesorge number. This instability is thermally induced in a droplet which does not experience instabilities without heating. (C) 2012 Elsevier Ltd. All rights reserved.

    Journal Title

    International Journal of Heat and Mass Transfer

    Volume

    59

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    316

    Last Page

    327

    WOS Identifier

    WOS:000316306700033

    ISSN

    0017-9310

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