TY - JOUR
T1 - Effective diffusivity of gas diffusion layer in proton exchange membrane fuel cells
AU - Shou, Dahua
AU - Fan, Jintu
AU - Ding, Feng
N1 - Funding Information:
The study was supported by The Hong Kong Polytechnic University Scholarship and a Discovery Project (Project ID: DP110103991) from Australia Research Council. a edge length of square, m C vapor density, g m −3 D b bulk diffusivity, m 2 s −1 D eff effective diffusivity, m 2 s −1 J diffusive flux, g s −1 m −2 l radial distance of a cell, m r fiber radius, m R cell radius, m S cell area, m 2
PY - 2013/3/1
Y1 - 2013/3/1
N2 - In gas diffusion layers (GDLs) of proton exchange membrane fuel cells (PEMFCs), effective gas diffusivity is a key parameter to be determined and engineered. Existing theoretical models of effective diffusivity are limited to one-dimensional (1D) regular fiber arrays. Numerical simulations were carried out to simulate gas diffusion through more realistic fibrous materials like GDLs, in which fibers are randomly distributed in a two-dimensional (2D) plane or three-dimensional (3D) space, but they could not fully reveal the underlying mechanisms. In this paper, we propose an analytical model to predict the effective diffusivities of 1D, 2D and 3D randomly distributed fiber assembles. The present model is established by extending the model of 1D regular fiber alignments to 1D random fiber arrangements through Voronoi Tessellation method, and using the 1D local diffusivities to determine the 2D and 3D diffusivities based on mixing rules. The predicted effective diffusivities agree well with experimental results and numerical data. With the new model, the influences of porosity, fiber distribution, and fiber orientation are analyzed in this study.
AB - In gas diffusion layers (GDLs) of proton exchange membrane fuel cells (PEMFCs), effective gas diffusivity is a key parameter to be determined and engineered. Existing theoretical models of effective diffusivity are limited to one-dimensional (1D) regular fiber arrays. Numerical simulations were carried out to simulate gas diffusion through more realistic fibrous materials like GDLs, in which fibers are randomly distributed in a two-dimensional (2D) plane or three-dimensional (3D) space, but they could not fully reveal the underlying mechanisms. In this paper, we propose an analytical model to predict the effective diffusivities of 1D, 2D and 3D randomly distributed fiber assembles. The present model is established by extending the model of 1D regular fiber alignments to 1D random fiber arrangements through Voronoi Tessellation method, and using the 1D local diffusivities to determine the 2D and 3D diffusivities based on mixing rules. The predicted effective diffusivities agree well with experimental results and numerical data. With the new model, the influences of porosity, fiber distribution, and fiber orientation are analyzed in this study.
KW - Analytical model
KW - Effective diffusivity
KW - Fibrous media
KW - Gas diffusion layers
KW - Proton exchange membrane fuel cell
UR - http://www.scopus.com/inward/record.url?scp=84868305836&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2012.10.039
DO - 10.1016/j.jpowsour.2012.10.039
M3 - Journal article
AN - SCOPUS:84868305836
SN - 0378-7753
VL - 225
SP - 179
EP - 186
JO - Journal of Power Sources
JF - Journal of Power Sources
ER -