Multiscale modeling of an angled gas diffusion layer for polymer electrolyte membrane fuel cells: Performance enhancing for aviation applications

Abstract

Green hydrogen powered polymer electrolyte membrane fuel cells (PEMFCs) seem promising for the main propulsion power of future aviation applications. This work establishes a systematic simulation tool for PEMFC studies via seamlessly embodying multiscale models from stochastic reconstruction, through pore scale modeling (PSM), to macroscale computational fluid dynamics (CFD) multi-phase and physics assessing. Using the tool, a novel angled gas diffusion layer (GDL) design, compared to the conventional multi-layer design, is proposed, simulated and studied. Stochastic reconstruction is employed in the GDL structural numerical reconstruction. PSM is charged for the effective transport properties. Results from the CFD simulations show significant gains (tens of percent) in the cell output power and limiting current under the new GDL design. PSM justifies that these gains are primarily sourced from the notable rise in the effective thermal conductivity accompanied by the moderate increase in the effective species diffusivity. PSM also predicts they can be further strengthened with larger fiber angles. All these performance boosts will further secure the competencies of PEMFCs aboard aviation applications. This study also reveals that the internal electric path of a PEMFC is already largely sufficient for the power output. On the other hand, a significant enhancement on the thermal path is still mostly lacking as a future work and to the research community.