Tranter, TG, Stogornyuk, P, Gostick, JT et al. (2 more authors) (2017) A method for measuring relative in-plane diffusivity of thin and partially saturated porous media: an application to fuel cell gas diffusion layers. International Journal of Heat and Mass Transfer, 110. pp. 132-141. ISSN 0017-9310
Abstract
A new experimental technique, extended from similar work on dry materials, is presented for measuring the in-plane components of the relative diffusivity tensor for partially saturated porous media. The method utilizes a custom-built holder and measures the transient response to oxygen concentration changes at the boundaries of a porous sample placed between two plates surrounded by a cooling block. The apparatus is kept close to the freezing temperature of water to ensure stable saturation throughout the experiment. Fick's second law is used to fit the transient change in concentration to a numerical solution to obtain the diffusion coefficient for samples of differing saturation. As expected the effective gas diffusivity is found to decrease with increasing water saturation of the media as the porosity is reduced and the tortuosity of the diffusion pathways increased. After extensive validation, this new technique is used to determine the relative in-plane diffusivity of some common fuel cell gas diffusion layer materials. The results are found to follow a power-law function dependent on the saturation consistent with previous modelling work. Samples without hydrophobic treatment are found to have lower relative gas diffusivity, compared with treated samples for the same average saturation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in International Journal of Heat and Mass Transfer. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Relative diffusivity; In-plane; Thin porous media; Fuel cell; Gas diffusion layer |
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: | 05 Apr 2017 10:09 |
Last Modified: | 03 Apr 2018 00:38 |
Published Version: | https://doi.org/10.1016/j.ijheatmasstransfer.2017.... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.ijheatmasstransfer.2017.02.096 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:114548 |