In-depth text simulation:
During the reaction of hydrogen and oxygen, water is produced. The produced water needs to be removed from the catalytic layer, where the reactions take place, to keep enough space available for new reactants. If there is not no exchange, an equilibrium evolves such that no electric energy is produced by the reactions. To ensure a continuous energy supply, the produced water is removed through the cathode of the cell. The water is transported through the different, porous layers. Water can be present in liquid or vapor form, due to condensation and evaporation. In this simulation, we consider the liquid water transport through the hydrophobic gas diffusion layer. This means, the water is the non-wetting phase on this coated carbon fiber material. On the pore-scale, this is an inhomogeneous and anisotropic structure. To investigate the water transport though this layer and to predict the break-through locations of the liquid water on the surface of the porous layer, a geometrical simplified model is used. The pore space of the material is represented by a network of pore bodies (network nodes) and pore throats (network connections). This allows an efficient calculation of the ongoing transport processes in the gas diffusion layer including the pore-scale effects. The simulation shows the locations, where liquid water first leaves the fibrous material. With this information, the gas diffusion layer structure can be optimized for the desired water distribution.
Pretty Porous
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Simulating processes in the fuel cell
Simulating processes in the fuel cell
Simulations are important in the research of fuel cells because they help to make processes in the fuel cell visible. With their help, researchers can understand the function of the porous layers. They understand how the transport of water, oxygen and hydrogen happens and whether they have to optimize the layers. Should they use a different material or structure? The knowledge they generate from the simulations can, for example, help to reduce costs during the vehicle production process.

Credits: University of Stuttgart / SFB 1313 / Cynthia Michalkowski
This example shows a model of a fuel cell GDL layer. With the help of this model it is possible to simulate the water proportion in the pores. The water is pressed through the porous layer and exits at the marked points