Flow field optimization for HTPEM fuel cells. A comparative study of serpentine-parallel and wavy flow channels

The design of flow fields plays a crucial role in the performance and durability of High-Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFCs), particularly due to the mechanical fragility of PBI membranes. This study presents a computational investigation of three flow field configurations: (i) a hybrid serpentine-parallel layout, (ii) a wavy channel with constant frequency, and (iii) a frequency-optimized wavy channel. All geometries were simulated using a fully coupled, three-dimensional, steady-state, non-isothermal CFD model implemented in ANSYS FLUENT, incorporating electrochemical source terms and multi-physics interactions. The results highlight significant differences in performance and pressure behavior among the analyzed designs. The optimized wavy configuration achieved the highest peak power density of 0.545 W/cm2, corresponding to a 37.8% increase over the baseline serpentine-parallel layout (0.396 W/cm2). In addition to enhanced electrochemical performance, the wavy geometry promoted a more homogeneous reactant distribution and significantly improved pressure uniformity across the membrane, supporting safer and more reliable operation under high load conditions.