CFD-DEM modeling of catalyst slurry flow and viscosity

0566496 - ÚT 2023 eng A - Abstrakt
Kotouč Šourek, M. - Studeník, O. - Isoz, Martin - Kočí, P. - York, A.
CFD-DEM modeling of catalyst slurry flow and viscosity.
[International Symposium on Modeling of Exhaust-Gas After-Treatment (MODEGAT VII) /7./. 11.09.2022-13.09.2022, Bad Herrenalb]
Institucionální podpora: RVO:61388998
Klíčová slova: CFD-DEM * OpenFOAM * HFDIB-DEM * rheology modeling * catalytic filters
Obor OECD: Chemical process engineering

Deposition of catalytic material on or into the porous filter wall has become widely used in the manufacturing of automotive exhaust gas after-treatment systems as the resulting catalytic filter can simultaneously treat gaseous and solid pollutants. However, the catalyst location inside the porous structure significantly influences the overall efficiency of the device. The catalyst distribution is highly affected by the slurry properties so that is important to understand its rheological behaviour during the washcoating process. In recent years, numerical simulations became a widely used tool in engineering practice as a support for experimental research. The simplest commonly used model is based on the so-called Eulerian-Eulerian approach, in which the solid phase is approximated as a fluid with an effective density and viscosity. However, it cannot capture any local fluid-solid interactions and relies on parameters fitted to experimental data for a specific suspension. An alternative to the Eulerian-Eulerian approach is to couple the CFD for the fluid with the discrete element method (DEM) for the solid phase, i.e. a CFD-DEM method. Such a model is based on first principles and includes fluid-solid as well as solid-solid interactions. In the present study, we utilize a newly developed solver based on the hybrid fictitious domain-immersed boundary (HFDIB) method and a level-set-like DEM to study suspension flows. Specifically, we performed simulations of the rheological properties of suspensions which differed in the solid phase volume fraction and in the shape of dispersed particles. First, we validated the proposed simulation setup via estimating the viscosity of a suspension made of spherical particles and comparing the estimates against available correlations and experimental data. Afterward, we investigated suspensions comprising non-spherical particles where no sufficient correlation for the viscosity is available in the open literature.
Trvalý link: https://hdl.handle.net/11104/0338250