The impact on PEMFC of bionic flow field with a different branch

The branching structure such as tree leaves, animal lungs and so on is universal and unique in nature. These structures are considered to be an optimal network channel for mass transfer and heat transfer. The mass transfer and heat transfer feature of bipolar plates in a proton exchange membrane fuel cell (PEMFC) is similar to them. In our research, the bionic similarity theory is used to design bionic flow fields for bipolar plates in PEMFCs based on leaf venation. It is demonstrated by numerical simulation that the PEMFC performance will be impacted by the number and location of branches in bionic flow fields. The location of branches has a greater impact on the exit velocity; the more branches there are, the more favourable is the discharge of water. Finally, different operating parameters (temperature, pressure, relative humidity, and stoichiometry) in bionic flow fields are chosen to study the PEMFC performance. In this way a kind of excellent flow field structure of bipolar plates in PEMFCs can be achieved. (C) 2012 Published by Elsevier Ltd.