27. November 2007 16:00 Uhr bis 17:30 Uhr
- Dr.-Ing. Steffen Oliver Ochs
Lehrstuhl für Hydromechanik und Hydrosystemmodellierung, Institut für Wasserbau, Uni Stuttgart
The development of new alternative power sources/supplies is animportant task nowadays. Polymer electrolyte membrane (PEM) fuel-cellscurrently are intensively investigated and improved for applications. This requires a profound understanding of the physical andelectrochemical processes elapsing in fuel cells. It has been foundthat the kinetics of the oxygen reduction at the cathodeis a limiting factor for the performance of fuel-cells. The transportof oxygen to the cathode through its porous diffusion layer occurs ina predominantly diffusive manner. The generation of liquid water atthe cathode-site constrains this oxygen transport to the reactionlayer. Thus, an efficient water management in the cathode diffusionlayer is necessary to improve the performance of the fuel-cell.
In the seminar we present a multiphase multicomponent model originally developed at LH2 for the simulation of non-isothermal multiphase processes in the subsurface and the modifications necessary for modeling multiphase processes in the diffusion layer of PEM fuel-cells.The results of two studies one on the influence of capillary pressure and another on the effect of different flow regimes on the system behavior will be discussed.
Pfaffenwaldring 61, Raum U1.003 (MML), Universität Stuttgart