PEMFC重构气体扩散层中两相传输的LB模拟

Investigation of Two-phase Flow in Reconstructed GDL of PEMFC by LBM

水管理问题是燃料电池最重要的问题之一。通过数值方法对气体扩散层(gas diffusion layer, GDL)多孔介质进行重构,基于多松弛时间格子玻尔兹曼方法模拟GDL中大密度比两相传输特性,讨论了多孔材料对液态水的接触角、格子之间的压力梯度、水-气粘度比以及液体表面张力对GDL内两相传输过程的影响。结果表明,接触角的增大会阻碍水的传递;表面张力的减小会导致水在计算区域中的渗透轻微减弱;压力梯度的增大促进了水在GDL内的传递。

Water management is one of the most important problems in fuel cells.In this paper,the gas diffusion layer(GDL)is numerically reconstructed and the water transport process in such porous medium is simulated based on the Multiple-Relaxation-Time Lattice Boltzmann(MRT-LB)method.The impacts of contact angle,surface tension and pressure difference on the water transport in GDL is investigated.The results show that the water content of GDL gradually decreases with the increase of the contact angle of GDL material,and the decrease of surface tension will lead to a slight decrease in the permeability of water in the computational domain.With the increase of pressure gradient,it promotes the transfer of water in the GDL.