Investigation of parametric periodic perturbed flow channels for performance improvement of proton exchange membrane fuel cell

The performance of proton exchange membrane fuel cells (PEMFCs) under high-load conditions is strongly affected by coupled flow and mass-transfer processes in cathode flow channels. In this study, a three-dimensional multiphysics model was used to investigate the effects of parameterized periodically perturbed channels on PEMFC transport and output performance. Five perturbed channel configurations, including sawtooth, sinusoidal, parabolic, trapezoidal, and elliptical channels, were compared with a conventional straight channel under identical geometric constraints. Combined with the field synergy principle and vortex-structure analysis, the mass-transfer enhancement mechanism was discussed from two aspects: periodic converging–diverging modulation and local curvature continuity. The results show that the elliptical channel provides the most favorable trade-off among the tested configurations. At 0.7 V, it achieves an EEC of 3.65 × 10−4 and increases the net power by 12.14% compared with the straight channel. Its peak power density reaches 0.798 W/cm2, corresponding to an 18.40% increase. The elliptical channel also improves oxygen utilization, reduces average liquid-water saturation, and provides a more uniform temperature distribution at the reaction interface. Additional amplitude-wavelength sensitivity analysis indicates that the relative advantage of the elliptical channel remains generally stable within the tested parameter range, although the benefit weakens when the amplitude decreases or the wavelength increases. These results provide comparative evidence for understanding how periodic perturbation geometry affects secondary-flow formation and mass-transfer enhancement in PEMFC cathode channels.