Numerical and Experimental Investigations on an Angular Approach Flowfield (AAF) Geometry for PEM Fuel Cells

In this study, we introduce and investigate numerically and experimentally the performance of an Angular Approach Flowfield (AAF) geometry for proton exchange membrane fuel cells (PEMFCs) and we compare three versions of this geometry (AAF V1.0, AAF V2.0, and AAF v2.1) to the conventional triple-serpentine (triple-serpentine homemade (TSHM)) one. The AAF V2.0 showed an improvement of 11% in numerical simulation compared to the triple serpentine geometry. However, this improvement was not replicated in the in-situ testing which may be attributed to the material used in the bipolar plates and the need for further hardware improvement. The introduction of channels in AAF V2.1 reduced the pressure drop but resulted in lower performance probably due to a non-optimal reactant distribution. In this study, we showed the impact of material properties and the assembly protocol on the performance of the fuel cell. We investigated the contact angle of the graphite used as well as the best torque (sealing and contacting pressure) to use in our hardware. These findings show the importance of flow-field design, material selection, and assembly conditions for achieving good velocity, pressure and oxygen distributions for enhancing PEMFC efficiency.