Multi-scale modeling of proton exchange membrane fuel cell by coupling finite volume method and lattice Boltzmann method

Lattice Boltzmann Pore-Scale Investigation of Coupled Physical-electrochemical Processes in C/Pt and Non-Precious Metal Cathode Catalyst Layers in Proton Exchange Membrane Fuel Cells

“…In this work, for the first time, the LBM is adopted to simulate the electrochemical processes (both reaction and transport) in a CL under PEMFC cathode conditions. The evolution equation for the concentration distribution function is as follows g i ðx þ c i Dt; t þ DtÞ À g i ðx; tÞ ¼ À 1 t g ðg i ðx; tÞ À g eq i ðx; tÞÞ þ a i S O 2 Dt (12) where g i is the distribution function with velocity c i at the lattice site x and time t. It is worth mentioning that for simple geometries, a D3Q7 (3 dimensional 7 lattice directions) lattice model (or D2Q5 model in 2D) is sufficient to accurately predict the diffusion process and properties, which can greatly reduce the computational resources, compared with D3Q19 (or D2Q9 in 2D), as proven by our previous work [29,33,34,[50][51][52][53]. For complex porous structures, especially for those with relatively low porosity such as CL, using a reduced lattice model will damage the connectivity of certain phases, thus leading to underestimated effective transport properties.…”

“…The evolution equation, the equilibrium distribution functions, and the relationship between collision time and proton conductivity for proton transport are similar to those used for oxygen concentration distribution functions. The related expressions are not repeated here for brevity [33].…”

“…Porescale simulations can be used to improve the fundamental understanding of reactive transport processes in porous media. The importance of pore-scale simulations is reflected in the increasing number of studies about pore-scale studies of reactive transport phenomena in Pt-based PEMFCs [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. However, pore-scale studies related to NPMCs-based PEMFCs has not been reported.…”

A unified coupling scheme between lattice Boltzmann method and finite volume method for unsteady fluid flow and heat transfer

“…A compression operator (CO) is employed at the macroscopic boundary for the information transfer from the micro/mesoscale to the macroscale and a reconstruction operator (RO) is adopted at the micro/mesoscopic boundary for the inverse information transfer [7]. Based on this strategy, many coupling methods between different numerical models have been proposed for various multiscale problems, such as molecular dynamic (MD)-continuum [8][9][10][11][12][13], direct simulation of Monte Carlo (DSMC)-continuum [14,15], and lattice Boltzmann method (LBM)-finite volume method (FVM) [16][17][18][19][20][21].…”

“…complex boundaries due to its flexibility [24] and the FVM can be adopted in the free area to speed up the computation [5]. This kind of coupling method has been used to simulate the lid-driven cavity flow [5], the natural convection [16], the flow around a circular cylinder, an airfoil, a porous medium [17] and the fluid flow and mass transfer in a proton exchange membrane fuel cell [18,19].…”