Three-Dimensional Non-Isothermal CFD investigation of proton exchange membrane fuel Cells: Coupled Thermal–Electrochemical analysis and performance evaluation

Abstract

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) are among the most promising clean energy conversion technologies due to their high efficiency, rapid dynamic response, and near-zero emissions. To improve performance and durability, it is essential to understand the complex coupling between electrochemical reactions, mass transport, and heat transfer occurring within the cell. In this study, a detailed three-dimensional (3D) non-isothermal Computational Fluid Dynamics (CFD) model was developed to investigate the coupled electrochemical and thermal transport phenomena in a PEMFC equipped with a branched serpentine flow field. The model captures the spatial distributions of electric potential, oxygen concentration, water vapor, temperature, and current density across the membrane–electrode assembly (MEA). Simulation results revealed pronounced temperature gradients within the MEA, significantly influencing water management, current density uniformity, and proton conductivity. The branched serpentine geometry improved reactant distribution and reduced pressure drop by approximately 18 % , while enhancing current–density uniformity by 6 % compared to a conventional serpentine layout. The model predicted a maximum temperature difference of 7.4 °C across the MEA, corresponding to a thermal regulation efficiency of 91 % . Furthermore, simulated polarization curves showed strong agreement with experimental data, with less than 4 % deviation , validating the model’s predictive accuracy. These findings highlight the critical importance of effective thermal management and controlled water transport in maintaining membrane hydration and achieving high energy-conversion efficiency. The developed CFD framework provides a reliable platform for optimizing PEMFC design under realistic operating conditions and offers quantitative insights for improving hydrothermal regulation, enhancing material durability, and guiding the development of next-generation high-performance fuel cell systems. All simulations were performed using COMSOL Multiphysics 6.2 , with user-defined electrochemical and heat-transfer equations implemented to capture the coupled non-isothermal behavior.

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