Spatially and temporally resolved modeling of low-temperature proton exchange membrane fuel cells is important for optimizing the efficiency of individual components, ensuring their durability, managing the content and dynamics of liquid water, and preventing overheating, thereby improving the efficiency and reliability of the systems in which they are implemented.
In this thesis, the provided 1D+1D physico-chemically consistent fuel-cell performance model is analysed. Based on the acquired knowledge, an appropriate numerical approach is proposed and an innovative upgrade is implemented, introducing additional segmentation of the gas diffusion layer in the direction transverse to the reactant-supply and product-removal channels. The developed model is coupled with the existing performance model and extended with arbitrarily prescribed profiles of the material properties of the segmentation layers, with emphasis on porosity, tortuosity, and contact angle. This is achieved by expanding the spatial discretization and the associated linear system, generating linear, exponential, and logarithmic profiles between the boundary values, and computing segment-wise effective diffusion coefficients. The advantage of the approach is higher spatial resolution within the GDL while preserving the conservative finite-volume formulation and a computational cost comparable to the original 1D+1D model. The results show more pronounced changes in gaseous reactant concentrations for porosity profiles, whereas contact angle profiles have a stronger influence on the distribution of liquid-water content.
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