In a polymer electrolyte membrane fuel cell, effective water management is required for optimal cell performance. While membrane hydration is needed for effective proton conduction, an excess of water, particularly on the cathode side, hinders transport of oxygen to the catalyst sites and lowers cell voltage. This study utilized neutron radiography to reveal the presence of liquid water while operating the PEMFC. These insitu experiments investigated both rectangular and triangular flow field geometries, various flow field surface energies, and several gas diffusion media samples. Correlations were drawn between accumulated water mass and performance data collected during the imaging process. The analysis resulted in a visualization of the two-phase behavior inside the running fuel cell, and a time-averaged volumetric plot of the water developing in the GDM and cathode channels. Results show a change of 0.05g in averaged liquid water mass demonstrates a flooding condition. This small volume is associated with accumulated water in the electrode layer being the primary contributor to mass transport loss at high load. It is further demonstrated that the cathode flow field channel surface energy and cross-sectional geometry affect the size and distribution of water slugs inside the channels.
Library of Congress Subject Headings
Fuel cells--Research; Polyelectrolytes
Department, Program, or Center
Mechanical Engineering (KGCOE)
Owejan, Jon, "Neutron radiography study of water transport in an operating fuel cell: effects of diffusion media and cathode channel properties" (2003). Thesis. Rochester Institute of Technology. Accessed from
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