authors
- GARCIA SALABERRI, PABLO ANGEL
- GOSTICK, JEFF T.
- ZENYUK, IRYNA V.
- HWANG, GISUK
- VERA COELLO, MARCOS
- WEBER, ADAM Z.
On the Limitations of Volume-Averaged Descriptions of Gas Diffusion Layers in the Modeling of Polymer Electrolyte Fuel Cells
Articles
Overview
published in
- ECS Transactions (discontinued) Journal
publication date
- October 2017
start page
- 133
end page
- 143
issue
- 8
volume
- 80
Digital Object Identifier (DOI)
International Standard Serial Number (ISSN)
- 1938-6737
Electronic International Standard Serial Number (EISSN)
- 1938-5862
abstract
- Understanding of the coupled transport processes that occur in thin gas diffusion layers (GDLs) is necessary to develop improved designs. The traditional technique used to model GDLs is the volume-averaged approximation. However, the applicability of this approach has been long questioned, and the error in the results is unclear. In this work, the limitations of GDL volume-averaged models are examined under single-phase conditions. The lattice Boltzmann method is combined with tomography images of carbon-paper GDLs to assess the existence of a representative elementary volume (REV) in terms of various effective properties. Then, the predictions of GDL volume-averaged and pore-scale formulations are compared by using a CFD model of a differential cell. The results show that a REV cannot be clearly defined. This leads to inhomogeneities in the pore-scale model that the volume-averaged model is not able to capture despite the overall flux through the GDL is similar in both cases.