Three-dimensional full-scale modeling and validation of a kW-grade air-cooled proton exchange membrane fuel cell stack incorporating full fan morphology

Air-cooled proton exchange membrane (PEM) fuel cells have great application potential in unmanned aerial vehicles (UAVs), etc., due to their reduced system weight and complexity. Thermal management is crucial for this type of fuel cells, especially for hundred-cell stacks (kW-grade power), to ensure adequate membrane hydration and heat dissipation, which highly rely on fan’s operation and arrangement. In this study, we built a three-dimensional (3D) full-scale model of air-cooled stack consisting of 95 cells, in which the full morphology of all basic cell components, fan blade, air plenum and bolts are all incorporated, achieving a high level of geometric fidelity. The turbulent air flow generated by the rotation of fans is simulated by the multiple reference frame (MRF) model integrated with Reynolds-Averaged Navier-Stokes (RANS) model. This full fan morphology model is then integrated with a 3D fuel cell stack model describing multi-physics transfer and electrochemical reactions. And the accuracy of this model is validated against both the 95-cell stack’s polarization/power curves and the individual cell voltages at various current densities. Moreover, the influence mechanism of the air flow generated by fan rotation on the distribution characteristics of temperature, velocity, oxygen concentration, and so on in the stack is revealed in detail. This work establishes a practical simulation framework for designing and optimizing industrial kW-grade air-cooled stacks, providing actionable insights for fan specification, operational mode configuration, and thermal management design.