摘要：

采用商业软件FLUENT中VOF模型模拟了质子交换膜燃料电池（PEMFC）中液态水在具有粗糙气体扩散层（GDL）表面的气体通道（GC）中的传递过程。考察了GDL表面润湿特性和粗糙度对液态水传输过程的影响。研究结果表明：和亲水GDL表面相比，疏水GDL表面有利于液态水的排出；和光滑疏水GDL表面相比，粗糙疏水GDL表面加快了液滴的排出，减小了液滴覆盖GDL表面的面积；同时，粗糙GDL表面增加了GC

Abstract:

This paper aims at investigating the effect of the rough gas diffusion layer (GDL)on liquid water transport behaviors in gas channels (GCs)employing the volume of fluid (VOF)in the commercial CFD package, FLUENT 6.3.26.It is found that the liquid water on the hydrophilic rough GDL tends to spread along the corner and presents as a water film with the concave surface, with many holes in the GDL covered by the liquid water, whereas the liquid water on hydrophobic rough GDL presents as the water droplet which covers less holes and can be easily drained out of the GC, indicating that a hydrophobic GDL surface is desirable in PEMFCs.Simulations then focus on investigating the effects of the rough hydrophobic GDL on the liquid water transport behaviors in GCs.The simulation results show that the droplet is inclined to form the Cassie droplet on the rough GDL surface.The water droplet is easier to be drained out of the GC with the rough GDL surface.The water coverage ratio for the cases with the rough GDL surfaces is lower than that with the smooth GDL surface.The higher the roughness is, the less the GDL surface is covered by water.The pressure drop in the GCs increases with the increase of GDL surface roughness.