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The world's major automotive manufactures are engaged in an historic race to develop Proton Exchange Membrane (PEM) fuel cells as clean, high-efficiency alternatives to internal combustion engines for automotive power. PEM fuel cell technology not only holds out the promise of a more environmentally friendly automobile, but also of an extremely versatile power generation system with a broad spectrum of applications. The Computational Fuel Cell Dynamics-II (CFCD-II) workshop will address the emerging issues in computational PEM fuel cell modeling, particularly water management and electro-chemistry in the context of ion transport and multi-phase flow within the nanopores of the polymer electrolyte membrane.
PEM fuel cells generate electric potential by separating the oxidation of hydrogen into two catalysed steps performed on opposite sides of an electrolyte membrane. The end products are water, water vapor, and heat. The electrolyte membrane is a complex polymer comprised of Teflon spines from which typically hydrophilic SO_3^- groups extend. These are arranged in a nanoscale configuration which facilitates the selective diffusivity of the membrane, enabling the fuel cell to perform close to the thermodynamic limit for efficiency. The membrane must be well hydrated to function, however overproduction of liquid water may saturate the surrounding porous electrodes and leads to pronounced drops in power density. The control of the motion and distribution of liquid water in both the nano-structure of the membrane and the surrounding fibrous electrodes is referred to as water management, and is critical to effective cell operation.
A proper modeling of the transport process requires understanding of the interactions of water and ions within the polymer membrane. These issues lead to intriguing mathematical phenomena at the limit of continuum mechanics, including degenerate free-boundary problems requiring novel computational methods. The development of a predictive computational model of water management requires an understanding of the fundamentals of liquid transport in nano-scale pores, in turn demanding development of innovative numerical schemes to adapt to the widely disparate time and length scales present in the system.
The CFCD-II workshop is a continuation of the CFCD meeting hosted by PIMS and Ballard Power Systems at Simon Fraser University in June 2001. This meeting brought together mathematicians, engineers, and industry representatives in the PEM fuel cell community to exchange expertise and find common ground. It is the goal of the CFCD-II workshop to build upon this effort, uniting researchers from computational and applied mathematics, chemical engineering, mechanical engineering, polymer chemistry, and electrochemical engineering; setting a framework for future research directions, and seeding multi-disciplinary efforts which will lead to the development of a new generation of analytical and computational tools for PEM fuel cell design.
Final Report (in PDF format)