Low-pressure twin-fluid atomization: Effect of mixing process on spray formation

The present work comparably examines four different twin-fluid atomizers operated under the same op- erating conditions. Spray formation was examined by several approaches. The internal flow pattern was estimated using a simplified analytical approach, and the results were supported by the observation of the liquid discharge in the near-nozzle region. A high-speed back illumination was used for visualisation of the primary breakup. In the region of fully developed spray, the dynamics of droplets was studied using a phase-Doppler analyser (PDA). The information obtained from all methods was then correlated. Results show that the spray formation process depends mainly on the internal design of twin-fluid at- omizer at low gas to liquid ratios (GLR). The amount of gas influences the character of the internal two- phase flow, a mechanism of the liquid breakup, droplet dynamics and a resulting drop size distribution. Differences among the atomizers are reduced with the increase in GLR. Moreover, it was shown that a certain mixing process can inherently create the annular internal flow which generates a stable spray characterized by relatively low mean droplet size.

Keywords

Low-pressure, Atomization, Twin-fluid, Droplet dynamics, Liquid breakup, Back illumination

Citation

INTERNATIONAL JOURNAL OF MULTIPHASE FLOW. 2017, vol. 89, issue 1, p. 277-289.
http://www.sciencedirect.com/science/article/pii/S0301932216300271

Document type

Peer-reviewed

Document version

Accepted version

Language of document

en

Document licence

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/