Khatir, Z orcid.org/0000-0002-7559-7644, Kubiak, KJ orcid.org/0000-0002-6571-2530, Jimack, PK orcid.org/0000-0001-9463-7595 et al. (1 more author) (2016) Dropwise condensation heat transfer process optimisation on superhydrophobic surfaces using a multi-disciplinary approach. Applied Thermal Engineering, 106. pp. 1337-1344. ISSN 1359-4311
Abstract
Dropwise condensation has superior heat transfer efficiency than filmwise condensation; however condensate evacuation from the surface still remains a significant technological challenge. The process of droplets jumping, against adhesive forces, from a solid surface upon coalescence has been studied using both experimental and Computational Fluid Dynamics (CFD) analysis. Both Lattice Boltzmann (LBM) and Volume of Fluid (VOF) methods have been used to evaluate different kinematic conditions of coalescence inducing a jump velocity. In this paper, an optimisation framework for superhydrophobic surface designs is presented which uses experimentally verified high fidelity CFD analyses to identify optimal combinations of design features which maximise desirable characteristics such as the vertical velocity of the merged jumping droplet from the surface and energy efficiency. A Radial Basis Function (RBF)-based surrogate modelling approach using
design of experiment (DOE) technique was used to establish near-optimal initial process parameters around which to focus the study. This multidisciplinary approach allows us to evaluate the jumping
phenomenon for superhydrophobic surfaces for which several input parameters may be varied, so as to improve the heat transfer exchange rate on the surface during condensation. Reliable conditions were found to occur for droplets within initial radius range of r=20-40 μm and static contact angle θs~160º. Moreover, the jumping phenomenon was observed for droplets with initial radius of up to 500 μm. Lastly, our study also reveals that a critical contact angle for droplets to jump upon
coalescence is θc~140º.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Applied Thermal Engineering. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Condensation heat transfer; Super-hydrophobic surface; Jumping droplets velocity; Multi-disciplinary optimisation |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Computing (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Jul 2016 09:53 |
Last Modified: | 22 Feb 2022 14:58 |
Published Version: | http://dx.doi.org/10.1016/j.applthermaleng.2016.06... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.applthermaleng.2016.06.128 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:101833 |