Effect of air flow on liquid water transport through a hydrophobic gas diffusion layer of a polymer electrolyte membrane fuel cell

• Published in: International journal of hydrogen energy Vol. 35; no. 13; pp. 6872 - 6886
• Main Authors: Suresh, P.V., Jayanti, S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2010; Elsevier
• Subjects: Air flow; Alternative fuels. Production and utilization; Applied sciences; Channels; Cross-flow; Droplets; Ejection; Energy; Exact sciences and technology; Fuel cells; Fuels; Gas diffusion; Gas diffusion layer; Hydrogen; Hydrophobicity; Liquids; Polymer electrolyte membrane fuel cells; Transport; Two-phase flow; Water management; Water management; Cross-flow; Hydrophobicity; Gas diffusion layer; Two-phase flow; Polymer electrolyte membrane fuel cells; Gaseous diffusion; Two phase flow; Polymer electrolytes; Hydrogen; Water gas; Water flow; Flow field; Evacuation; Membrane; Fuel cell
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2010.04.052

The transport of liquid water through an idealized 2-D reconstructed gas diffusion layer (GDL) of a polymer electrolyte membrane (PEM) fuel cell is computed subject to hydrophobic boundary condition at the fibre–fluid interface. The effect of air flow, as would occur in parallel/serpentine/interdigitated type of flow fields, on the liquid water transport through the GDL, ejection into the channel in the form of water droplets and subsequent removal of the droplets has been simulated. Results show that typically water flow through the fibrous GDL occurs through a fingering and channelling type of mechanism. The presence of cross-flow of air has an effect both on the path created within the GDL and on the ejection of water into the channel in the form of droplets. A faster rate of liquid water evacuation through the GDL (i.e., more frequent ejection of water droplets) as well as less flooding of the void space results from the presence of cross-flow. These results agree qualitatively with experimental observations reported in the literature.