Análisis computacional de capas difusoras de gases en celdas de combustible: Estudio de porosidad y tortuosidad usando el método de Lattice Boltzmann

Abstract

CONDITION FOR PUBLICATION OF PROJECT. Climate change mitigation has highlighted fuel cells as a promising candidate for energy generation. In order to improve fuel cell efficiency, the influence of microstructural characteristics and the relationship between porosity and tortuosity in fibrous porous media are investigated. Three-dimensional computational domains representative of gas diffusion layers were generated with porosities ranging from 0.70 to 0.90, using increments of 0.01, and flow simulations were performed using the Lattice Boltzmann method. For each porosity value, 400 independent evaluations were conducted, allowing for a robust characterization of the porosity–tortuosity relationship, with variability exclusively associated with the distribution of the solid phase within the computational domain. The results revealed a decreasing relationship between porosity and tortuosity, demonstrating that more porous media exhibit transport pathways with lower geometrical complexity. Additionally, it was determined that fiber arrangement significantly influences tortuosity, even for similar porosity values. Finally, the numerical stability and convergence of the model were quantitatively verified, enabling reliable simulations and providing data that contribute to the improved design of gas diffusion layers with optimized transport properties. Keywords: Gas Diffusion Layers, Fuel Cells, Lattice Boltzmann Method, Porosity, Tortuosity