Study of fine structures for the two-phase flow control in the PEMFC channel

Abstract

The flow field design is an important approach to improve water management in exchange membrane fuel cells (PEMFCs), so it has always been a hot topic of research. We find that adding fine structures in the channel can change the two-phase flow behavior, which may improve the distribution of liquid water and promote water removal. In our research, four types of fine structures in the channel are investigated: continuous grooves, continuous bosses, intermittent grooves and intermittent bosses. The results show that the continuous grooves guide the water flow along the sidewall and the intermittent grooves create a disturbance to the airflow. Accordingly, liquid water has a faster discharge rate in the channel with continuous grooves and a more uniform distribution in the channel with intermittent grooves, which contribute to the water management in the channel. The boss structures should be avoided because they occupy much flow space and the liquid water near the bosses is difficult to remove. This work provides a new idea of channel design and confirms the effectiveness of the fine structure in water management. In the future, we will conduct further research on the shape and size of fine structures to achieve greater improvements in the water management capabilities of the flow channel.