Details

Autor(en) / Beteiligte

• CHAPUIS, O
• PRAT, M
• QUINTARD, M
• CHANE-KANE, E
• GUILLOT, O
• MAYER, N

Titel

Two-phase flow and evaporation in model fibrous media Application to the gas diffusion layer of PEM fuel cells

Ist Teil von

• Journal of power sources, 2008-03, Vol.178 (1), p.258-268

Ort / Verlag

Lausanne: Elsevier Sequoia

Erscheinungsjahr

2008

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Two-phase flow dominated by capillary effects in model fibrous media is studied combining pore-network simulations and visualisations on transparent micromodels. It is shown that the process of liquid water invasion in a hydrophobic medium can be simulated using the classical invasion percolation algorithm provided that the contact angle (measured in air, which is the wetting phase) is sufficiently far below 90[deg]. For contact angles approaching 90[deg], changes in the interface local growth mechanisms lead to changes in the invasion pattern. Then it is shown that the invasion pattern is dramatically different in a hydrophilic medium. Impact of wettability (hydrophobic vs. hydrophilic) on evaporation pattern is also analysed. In a last part, implications of the study findings on the water management problem in the gas diffusion layers (GDLs) of PEMFC are discussed. Our results provide pore-scale explanations to the advantages of hydrophobic GDLs.