CFD analysis of sinusoidal flow fields for High Temperature PEM Fuel Cells: Balancing electrochemical performance and mechanical safety

This study addresses the critical trade-off between electrochemical performance and mechanical integrity in High-Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFCs) operating in the 120–180 ° C range. Since phosphoric acid-doped PBI membranes exhibit low yield strength, conventional serpentine flow fields often induce pressure differentials that can lead to structural failure. A three-dimensional multiphysics model, rigorously calibrated against experimental data using a novel Gaussian Process Regression (GPR) protocol for efficient global parameter optimization, was employed to analyze hybrid serpentine-parallel and sinusoidal (wavy) channel configurations. Results demonstrate that wavy channels induce secondary flows that enhance reactant uniformity, increasing peak power density by up to 35% compared to the baseline. Crucially, the wavy geometry reduces the transmembrane pressure differential by more than 99% (from a critical 27 kPa to < 70 Pa), ensuring safe operation within the mechanical limits of commercial membranes. The constant-frequency wavy design is identified as the optimal configuration for industrial scale-up, balancing high performance with design simplicity. Finally, a parametric sensitivity analysis investigating the effects of temperature, pressure, membrane doping level, and stoichiometry was conducted to derive comprehensive operational guidelines for the optimized geometry. • A 3D HT-PEMFC model is rigorously calibrated via Gaussian Process Regression. • Wavy channels induce Dean vortices that enhance oxygen transport at the cathode. • The optimized geometry increases peak power density by 35% compared to the baseline. • Pressure drop is reduced below 70 Pa, ensuring PBI membrane mechanical safety. • Sensitivity analysis (T, p, stoichiometry, doping level) defines the optimal operating window for performance and durability.