Speaker
Description
We present an approach to simulate electrochemical processes in solid oxide fuel cells porous electrodes, focusing on the interplay of diffusion and ion exchange in their complex material structure. The ion exchange that takes place at the material interfaces leads to discontinuities that pose a challenge for numerical modeling. Solving diffusion problems within these domains leads to strongly oscillating solutions due to the complex microstructure. To overcome the computational challenges of directly resolving the microstructure, we apply a homogenization technique based on the asymptotic expansion approach. By separating macroscopic and microscopic scales, we derive a cell problem and a macroscopic problem. The homogenized model serves as an efficient approximation to the original microscopic model. An important aspect of this work is the treatment of interface discontinuities. Both the solutions of the microscopic problem and the cell problem exhibit discontinuities at material interfaces. To accurately model these discontinuities, we use extended finite elements (XFEM). Finally, the results of the microscopic and macroscopic models are compared, highlighting the effectiveness of the homogenized approach and the XFEM framework in capturing the multiscale behavior of the system.
