Modelling of Two-Phase Behaviour in the Gas Diffusion Layer of PEFCs.
J. Becker (Fraunhofer ITWM, Germany), V. P. Schulz (Fraunhofer ITWM, Germany) and A. Wiegmann (Fraunhofer ITWM, Germany)
Starting from a reconstruction of the three-dimensional fibrous microstructure of the gas diffusion layer (GDL) we apply the full morphology (FM) method to study the two-phase characteristics of the diffusion medium. By the FM method the distribution of the fluid phases and the capillary pressure curve is determined. Using these phase distributions we are able to determine permeability and diffusivity in dependance of the water saturation of the medium with comparatively low numerical cost. Based on this method the two-phase behaviour of the GDL under compression is studied.
Finally, we will give an outlook on modelling gas diffusion media containing microporous layers.