CFD Simulation of Flow Through the Reconstructed Microstructure of Fibrous Gas Diffusion Layer in a Polymer Electrolyte Membrane Fuel Cell

The gas diffusion layer (GDL) is one of the key components in a polymer electrolyte membrane (PEM) fuel cell. Generally it is a carbon-based fibrous medium that allows for the transport of electrons through the fibers and distributes the reactants through the void space to the catalyst layer in a PEM fuel cell. In the present work, a microstructure study of reactant transport is carried out by reconstructing the typical fibrous microstructure of the GDL and investigating the transport characteristics of the porous medium using computational fluid dynamics (CFD) simulations. The results confirm the applicability of Darcy's law formulation for permeability determination and Bruggemann correction for calculation of effective diffusivity for typical conditions encountered in PEM fuel cells. Macroscopic material properties such as through-plane and in-plane permeabilities and effective diffusion coefficient are determined and compared against experimental values reported in the literature.