Influence of fluid flow and heat transfer on crack propagation in SOFC multi-layered like material with anisotropic porous layers

Abstract

An advanced numerical model based on the eXtended Finite Element Method (XFEM) is developed and used to investigate the effect of heat transfer and fluid flow on crack propagation in multi-layered SOFC with anisotropic porous layers. Effect of the anisotropy on the onset and the propagation path of cracks are investigated. Heat transport in the porous media is described by heat convection in the fluid phase, and heat conduction in both the fluid and solid phases. A time splitting technique is used to allow different numerical treatment for the heat transfer processes within the porous layer. A combination of Discontinuous Galerkin (DG) and Multi-Point Flux Approximation (MPFA) methods are used to solve the advection–diffusion heat transfer in the flow channel and the fluid phase in the porous material. XFEM is used to solve the heat diffusion within the porous layers and the thermomechanical problem. The fluid flow, governed by Navier–Stokes and Darcy's law, is discretised with the nonconforming Crouzeix–Raviart (CR) finite element method. The multi-physics model is implemented and validated by comparing the computed Stress Intensity Factors (SIF) to ones from the literature. The methodology seems to be robust, accurate and the computational cost is reduced thanks to the XFEM.