Effective water removal and transport in the flow channel is significantly important to the critical water management in proton exchange membrane fuel cells (PEMFCs). In this work, we proposed a fin‐shaped flow channel with hydrophobic walls to enhance liquid water removal from the surface of gas diffusion layer (GDL). Computational fluid dynamics simulations with volume‐of‐fluid method were carried out to investigate the liquid water behavior in the fin‐shaped flow channel. The results indicated that the hydrophobic fin‐shaped flow channel can not only effectively remove the water droplets on the GDL surface, but also accelerate their transport, avoiding water accumulation; the appropriate length, width and depth of the fin‐shaped grooves are 2.0 mm, 0.3 mm and 0.7 mm for comprehensive consideration of the water removal and transport, and the pressure drop throughout the channel. This work provides an alternative to conventional straight flow channel, and is helpful for the designing of high output PEMFCs.

The flow field on bipolar plate of proton exchange membrane fuel cells (PEMFCs) plays a decisive role in cell performance. In this work, two compensated flow fields, termed separated multi‐serpentine flow field and combined multi‐serpentine flow field, were investigated to understand their effects on cell performance, flow uniformity and water removal capability. The results show that the compensated flow fields can significantly enhance flow uniformity and cross‐flow under the rib, compared with the conventional multi‐serpentine one, resulting in even distribution of current density. Furthermore, the combined multi‐serpentine flow field shows more uniform distribution of current density and stronger water removal capability than the separated one, because it combines the entrance parts and exit parts of the channels.

Effective water removal and transport in the flow field is significantly important to the critical water management in proton exchange membrane fuel cells (PEMFCs). In this work, a slope turn was proposed in the hydrophobic channel of the multi‐serpentine flow field, and the transport and dynamics of water in the modified flow channel were numerically investigated with the volume‐of‐fluid method. The simulation results indicated that, with the presence of the slope turn, the water droplet can be effectively detached from the surface of the gas diffusion layer although the channel walls are hydrophobic. Meanwhile, the hydrophobic channel walls are beneficial to decrease interfacial resistance of water transport, avoiding water accumulation in the flow channel. The wall contact angle, slope angle and gas flow velocity are three important factors which significantly affect water behavior and pressure drop in the flow channel. For considered cases in this work, the appropriate wall contact angle, slope angle, and gas flow velocity were proved to be 140°, 110°, and higher than 2 m s−1, respectively.