Validation of a Numerical Model for the Prediction of the Pressure Distribution in PEMFC Flow Field Plates With a Serpentine Channel

Much effort has been expended in the past few years upon development of numerical models to obtain the detailed flow, current and temperature distributions in Polymer Electrolyte Membrane Fuel Cell (PEMFC). Therefore, the need for model validation also has increased to gain confidence in the accuracy of the numerical results. In the present work, a numerical model has been developed to study the pressure distribution in the flow field plate (FFP) and gas diffusion layer (GDL) assembly on the cathode side of a PEM fuel cell. The flow field plate has serpentine channels and the porous gas diffusion layer is adjacent to the flow field plate, to deliver the air to the catalyst layer where the electrochemical reaction occurs. Flow crossover of air through the porous GDL under the land from one part of the channel to another can occur, and this flow crossover affects the total pressure drop between the channel inlet and outlet, and the pressure difference between adjacent channels. The flow here has been assumed to be three-dimensional, steady, incompressible, isothermal and single-phase. The flow through the porous GDL has been described using the Darcy model. The governing equations have been written in dimensionless form and solved by using the commercial CFD solver, FIDAP. In parallel, experimental work has been conducted at the Queen’s-RMC Fuel Cell Research Center (FCRC), Canada, for comparison with the numerical results. The cathode FFP has a single serpentine channel. Flow of dry air at 20 °C and at 60 °C has been used for measuring pressure differences at specific locations in the flow field plate. The effects of Reynolds number, based on the mean channel width and the mean velocity at the channel inlet (values between 100 and 1500) have been studied. Other parameters that were considered are the land:channel width ratio (2:1 and 1:1) and the permeability of the GDL (values between 1.0E−19m2 and 1.0E−10m2 used). Good agreement was obtained between the numerical and experimental pressure distributions along the serpentine channel.