Campus Units

Mechanical Engineering, Electrical and Computer Engineering, Plant Sciences Institute

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2019

Journal or Book Title

International Journal of Multiphase Flow

DOI

10.1016/j.ijmultiphaseflow.2019.03.006

Abstract

The liquid core of a canonical two-fluid coaxial atomizer has been characterized using synchrotron X-rays. The high energy photons allow for high-speed imaging of attenuation through the dense liquid-gas jet core, resolving the internal structures that include entrapped air bubbles and the formation of liquid ligaments and bags. When the gas-to-liquid momentum ratio increases, the liquid core transitions from an intact column, where primary break-up happens several liquid diameters downstream, to a hollow crown with a downstream span comparable to the liquid diameter that disintegrates by shedding ligaments from its rim. At high gas momentum ratios (limited by the sonic velocity at the gas nozzle exit), this crown suffers partial dewetting and, when angular momentum is added to the gas, it dewets on a large section of the liquid injection needle circumference. This partial crown exhibits azimuthal motions along the circumference, on timescales much longer than the relevant flow timescales. The crown attachment to the liquid needle presents a bi-stable nature. The dramatic changes of the liquid core morphology, as the gas momentum and swirl ratios vary, have a strong impact on the gas-liquid boundary layers, which control the liquid break-up mechanisms and the resulting spray characteristics, such as droplet size distributions and the droplet volume fraction across the spray.

Comments

This is a manuscript of an article published as Machicoane, Nathanael, Julie K. Bothell, Danyu Li, Timothy B. Morgan, Theodore J. Heindel, Alan L. Kastengren, and Alberto Aliseda. "Synchrotron radiography characterization of the liquid core dynamics in a canonical two-fluid coaxial atomizer." International Journal of Multiphase Flow (2019). DOI: 10.1016/j.ijmultiphaseflow.2019.03.006. Posted with permission.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Copyright Owner

Elsevier Ltd.

Language

en

File Format

application/pdf

Available for download on Saturday, March 13, 2021

Published Version

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