چكيده به لاتين
Proton exchange membrane (PEM) fuel cells are prime candidates for propulsion systems of modern electric vehicles. However, appropriate water management is crucial to performance. Cell compression can affect the performance and water management of PEM fuel cells. Although the effect of cell compression on the transport of continuous water flow through the porous electrodes is investigated, the effect of cell compression on the droplet dynamic behavior through these electrodes is not well-investigated. Employing a pore-scale simulation method such as lattice Boltzmann method (LBM) is one of the best means for such investigation. In first investigation, the influence of compression and contact angle on water droplet dynamic behavior during removal from GDL is inspected by numerous 3D LB simulation. Three different contact angles of 80, 105 and 150 has been investigated which each contact angle consists of four compressions of 0%, 15%, 20% and 25%. The results illustrate that in general influence of compression helps to water droplet removes from GDL easily but the role of contact angle is also important for example the contact angle of 150 (very hydrophobic) in compression of 25% helps to water droplet removes easily than other contact angles. However, for each contact angle a specific amount of compression exists in which water droplet removes from GDL sooner than other cases.
Second study is about the role of anisotropy parameter on the water droplet dynamic behavior. Anisotropy parameter equal to 1 denotes to the isotropic alignment of fibers, and larger amount of this parameter denotes to horizontally aligned fibers. In this study, the results show that for smaller water droplet size, increasing of anisotropy parameter helps water droplet removal from GDL. But for larger droplet size, increasing of anisotropy parameter does not help water droplet removal.
Keywords: PEM fuel cell; water management; gas diffusion layer (GDL); compression; contact angle; lattice Boltzmann method (LBM).
