A Three-dimensional, Two-fluid Model of PEM Fuel Cell Cathodes

Abstract

This research focuses on the analysis of multi-phase flow through the porous media of the cathode side of a PEM Fuel Cell using a three-dimensional, multi-fluid model based on computational fluid dynamics (CFD). In a first step, it is assumed that all product water exists and leaves the cell in the liquid phase, and its flow through the catalyst layer, micro-porous layer, and gas diffusion medium is investigated as function of in- and through plane hydraulic permeability, effective contact angles, and irreducible saturation of each layer. The effect of under-the-land compression on the predicted water saturation level will be discussed. Finally, the important role of the pore size distribution of the porous media on the liquid water transport and predicted saturation level ("flooding") is highlighted, and a qualitative approach to obtain the capillary pressure curve as function of liquid saturation for different types of porous media will be outlined.