Al-Dirawi, KH and Bayly, AE orcid.org/0000-0001-6354-9015 (2019) A new model for the bouncing regime boundary in binary droplet collisions. Physics of Fluids, 31 (2). 027105. ISSN 1070-6631
Abstract
This work experimentally investigates binary collisions of identical droplets over a range of liquid viscosities, using 2%, 4%, and 8% of hydroxypropyl methylcellulose solutions in water. The collisions were captured by using a high-speed camera, and regime maps of collision outcomes were derived. The performance of existing models of the boundary of the bouncing regime was assessed and found to give poor predictions. This was attributed to assumptions and errors in the treatment of kinetic energy and the droplet shape factors used in these models. A new model was derived which addresses these issues: the definition of the kinetic energy that contributes to deformation was corrected; a new shape factor that accurately reflects the geometry of the droplet at maximum deformation was proposed, and, importantly, an empirical approach was implemented to account for the effect of the impact parameter on this shape factor. Moreover, the model includes an estimate of the viscous dissipation, which is calculated directly from the experimentally observed difference between the impact and the rebound kinetic energies and measurements of the post-collision droplet oscillations. The proposed model shows a striking improvement versus the existing models, reducing the mean absolute error by an order of magnitude.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Author(s). This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Al-Dirawi, KH and Bayly, AE (2019) A new model for the bouncing regime boundary in binary droplet collisions. Physics of Fluids, 31 (2). 027105. ISSN 1070-6631 and may be found at https://doi.org/10.1063/1.5085762. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | droplets; collisions; fluid dynamics; multiphase flow |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 May 2019 11:19 |
Last Modified: | 14 May 2019 11:19 |
Status: | Published |
Publisher: | AIP Publishing |
Identification Number: | 10.1063/1.5085762 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:146008 |