Numerical Simulation of Water Transport in a Proton Exchange Membrane Fuel Cell Flow Channel

Water management of proton exchange membrane fuel cells (PEMFCs) is crucial to maintain high performance and stable operation. The flow channel is an indispensable part of PEMFCs, which allows the reactant gases to flow into the system, and the liquid water to be removed from the fuel cells. A transient 3D model based on volume of fluid methodology is used to study the dynamic characteristics of gas-liquid two-phase flow in a PEMFC flow channel. The structure of the flow channel, the wettability of channel surfaces, the air inlet velocity, the dimensions of the water droplets, and the effect of phase transition are considered to obtain the optimal solution. The results show that the water droplet transport process is seriously affected by the wettability of the channel surfaces. A modified surface design with varied static surface contact angle could perform the detachment without external force with an appropriate initial velocity. Besides, phase transitions could seriously influence the form and the distribution of water existing in the channel.