NUMERICAL INVESTIGATION OF FLOW FIELD IN PROTON EXCHANGE MEMBRANE FUEL CELL AT DIFFERENT CHANNEL GEOMETRIES

This paper reports the three-dimensional modelling of a proton exchange membrane fuel cell (PEMFC) with straight flow field designs. Different shapes of both anode and cathode channels have been considered. Three geometrical configurations with same area: rectangular, triangular and elliptical straight channels are constructed to investigate the performance and the transport phenomena in the PEMFC at high and low operating voltages. The proposed model is a full cell, which includes different physical zones associated with a PEM fuel cell such as the Bipolar Plates (BPs) or current collectors, the flow channels, the Gas Diffusion Layers (GDLs), and the Catalyst Layers (CLs) on both anode and cathode sides as well as the membrane layer. The model is implemented into the commercial computational fluid dynamics (CFD) software package Fluent® 6.3, with its user-defined functions (UDFs). The continuity, momentum, chemical species and charge conservation equations are coupled with electrochemical kinetics in the anode and the cathode channels and the Membrane Electrode Assembly (MEA). The obtained results determine that at high voltage (0.8 V) the cell performance is insensitive to the channel shape. The simulation results show that at low voltage (0.4 V) when anode and cathode channels geometry is triangular the performance of the cell is better than the rectangular and elliptical channels. The best performance is obtained for a triangular channel width of 0.1 mm