Performance and durability of solid oxide cell (SOC) electrodes are closely linked to their microstructure properties. Thus, the comprehensive characterization of 3D microstructures e.g., obtained by FIB-SEM tomography is essential...
Numerical implementation schemes of drag force effects on Lagrangian particles can lead to instabilities or inefficiencies if static particle time stepping is used. Despite well known disadvantages, the programming structure of the underlying, C++ based, Lagrangian particle solver led to the choice of an explicit EULER, temporal discretization scheme. To optimize the functionality of the EULER scheme, this paper proposes a method of adaptive time stepping, which adjusts the particle sub time step to the need of the individual particle. A user definable adjustment between numerical stability and calculation efficiency is sought and a simple time stepping rule is presented. Furthermore a method to quantify numerical instability is devised and the importance of the characteristic particle relaxation time as numerical parameter is underlined. All derivations are being conducted for (non-)spherical particles and finally for a generalized drag force implementation. Important differences in spherical and non-spherical particle behaviour are pointed out.
In filtration processes it is necessary to consider both, the interaction of the fluid with the solid parts, as well as the effect of particles carried in the fluid and accumulated on the solid. In this first part a closer look is taken on the influence of the fluid on the solid regions. The required algorithm to couple the governing differential equations is derived on the basis of the equations, governing the solid and fluid regions. For discretization, only one single computational mesh is used and this is adjusted to the deformation at each time-step. The simulation of the fluid-structure interaction is realised in a single finite volume flow solver on the basis of the OpenSource software OpenFoam.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.