目前，针对质子交换膜燃料电池(PEMFC)性能的数值模拟研究大多假设气体扩散层(GDL)的多孔介质孔隙率一致，但实际上 GDL 受双极板脊背压缩产生的变形会导致
孔隙率的非一致性． 文中针对装配压力引起的 GDL 变形及非一致孔隙率情况，基于有限元理论和计算流体力学软件，在 FLUENT 中导入力学分析得到非一致孔隙率的自定义函数(UDF)． 模拟结果表明:脊部下方 GDL 由于孔隙率的变化使得沿 Y 方向截面纵向气体的流速往双极板方向的递增;且孔隙率的非一致性导致脊部下方的气体浓度较流道下方降低、水含量增大，产生积水现象，这些变化将不利于燃料电池性能的保持． 然后在验证函数准确性的同时探究了电池温度、湿度等参数随燃料电池电压的变化规律，并研究了燃料电池内部温度的变化． 发现流道下方阴极侧电化学区域比阳极侧温度高，反映了实际燃料电池中阴极侧水堆积现象造成热的传输速度慢于阳极侧的实际情况．

At present,for the numerical simulation of the PEMFC (Proton Exchange Membrane Fuel Cell) perfor- mance,it is assumed that the porous media in the GDL (Gas Diffusion Layer) has a constant porosity.But in fact,the GDL deformation caused by the compression of bipolar plate ribs can lead to the non-uniform porosity of the GDL.In this paper,aiming at the GDL deformation and the non-uniform porosity,which are caused by the assembly pres- sure,based on the finite element theory and the computational fluid dynamics software,a non-uniform porosity func- tion (UDF,User Defined Function) is deduced by introducing the structural mechanics analysis into a FLUENT simu- lation model.Simulation results show that,for the GDL below the rib,the changes of the porosity cause the gas flow rate in the longitudinal section in the Y direction to increase from the middle to the bipolar plates,and that,due to the nonuniformity of the porosity,the gas concentration below the rib is lower than that below the flow chan- nel,and the water content increases leads to a water accumulation phenomenon,which are negative to maintaining the performance of fuel cells.Moreover,the accuracy of the deduced function is verified,meanwhile the change rules of the operating temperature and humidity with the fuel cell voltage are discussed,and the temperature distribution inside the fuel cell is also investigated.It is found that the temperature of the electrochemical region at the cathode side below the flow channel is higher than that at the anode side,which reflects that,for the actual fuel cell,the water accumulation phenomenon at the cathode side causes its heat transfer speed to be slower than that at the anode side.