Water is produced at the interface between the MEA and the cathode porous diffusion layer as a result of electrochemistry and water transport due to water drag in PEMFC. If the cathode gas flow is saturated, this water is produced in liquid form. A multiphase mixture model has been incorporated to predict the flow of liquid water through the porous diffusion layers and into the flow channels. The multiphase mixture model solves for conservation of mass, momentum, energy, and species in the porous diffusion layer. In addition to describing the liquid water flow, this model will produce local values of the liquid volume fraction within the porous media. The resultant effect on local void fraction will be used to modify the local values of gas phase diffusivity, thermal conductivity, and electrical conductivity throughout the cathode diffusion layer. This modification to the transport properties for local water concentration will accurately model the effect of water production on mass diffusion, heat conduction, and electrical conduction though the cathode diffusion layer.

Serpentine PEMFC geometry