Application of lattice Boltzmann method to a micro-scale flow simulation in the porous electrode of a PEM fuel cell
Application of lattice Boltzmann method to a micro-scale flow simulation in the porous electrode of a PEM fuel cell
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DOI：
10.1016/j.jpowsour.2007.04.021
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发表时间：
2007-11
影响因子：
9.2
通讯作者：
J. W. Park;M. Matsubara;Xianguo Li
中科院分区：
文献类型：
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作者：
J. W. Park;M. Matsubara;Xianguo Li
质子交换膜燃料电池的电极是一种多孔介质，通常由碳布或纸制成。在质子交换膜燃料电池的文献中，这种多孔电极被广泛地模拟为具有恒定渗透率的均匀多孔介质。事实上，大多数气体扩散介质都不是均质的，具有非各向同性的渗透率。在碳布的情况下，多孔结构由碳纤维束、碳纤维束和丝束之间的空隙组成。多孔电极的有效渗透率是由空隙空间和两个渗透率共同作用的结果。本文将格子Boltzmann方法应用于质子交换膜燃料电池电极内的流动模拟。将电极模拟为具有一定渗透率的孔洞空间和多孔区，在流场中采用格子Boltzmann模型求解Stokes方程和Brinkman方程。对多孔介质的有效渗透率进行了计算，并与解析计算进行了比较，两者吻合较好。三维数值模拟表明，多孔介质的渗透率强烈依赖于纤维丝束的取向。格子Boltzmann方法是分析多孔介质等复杂几何结构中流动的一种高效的数值方法。
The electrode of a PEM fuel cell is a porous medium generally made of carbon cloth or paper. Such a porous electrode has been widely modeled as a homogeneous porous medium with a constant permeability in the literature of PEM fuel cell. In fact, most of gas diffusion media are not homogeneous having non-isotropic permeability. In case of carbon cloth, the porous structure consists of carbon fiber tows, the bundles of carbon fiber, and void spaces among tows. The combinational effect of the void space and tow permeability results in the effective permeability of the porous electrode. In this work, the lattice Boltzmann method is applied to the simulation of the flow in the electrode of a PEM fuel cell. The electrode is modeled as void space and porous region which has certain permeability and the Stokes and Brinkman equations are solved in the flow field using the lattice Boltzmann model. The effective permeability of the porous medium is calculated and compared to an analytical calculation showing a good agreement. It has been shown that the permeability of porous medium is strongly dependant on the fiber tow orientation in three-dimensional simulations. The lattice Boltzmann method is an efficient and effective numerical scheme to analyze the flow in a complicated geometry such as the porous medium.