Clean Technology 2008
R. Schultz, J. Diebel, J. Allen
Michigan Technological University, US
fuel cell, water management, fluidic oscillator
To achieve maximum efficiency and reliability in a PEM fuel cell, a balance between keeping the membrane from becoming too dry or too wet must be monitored carefully. At present, product water is moved through the channels to the exit via the gas flow only. The movement of the water drops in the gas flow channels is inhibited by pinning of the three-phase region where the gas, liquid and solid coincide. This paper discusses enhanced water removal from the gas flow channels of a PEM fuel cell by oscillation of water drops near their natural frequency. The oscillations are induced through modulation of the reactant gas flow using fluidic elements. This technique has significant potential due to the absence of external actuators and controls. There are no moving parts and the oscillators could be cast directly into the bipolar plates during manufacturing.