Sebastian Smyk, SFB 1313, doctoral researcher at the Institute of Applied Analysis and Numerical Simulation (research project C02), will give his milestone presentation on "Modelling of chemically induced fluid/solid phase transformations" on 19 April 2024.
Date: Friday, 19 April 2024
Time: 2:00 pm CET
Title: "Modelling of chemically induced fluid/solid phase transformations"
Place: Campus Vaihingen, Pfaffenwaldring 57, 7.133
Abstract
The understanding of chemical processes plays a crucial role in modelling reactive multi-phase systems, as these processes typically induce phase-transformations. An example of such a system is a fluid/solid system, in which the solid phase either growths or shrinks due to precipitation or dissolution of reactive particles at the fluid/solid interface. Hereby, these surfactants are typically transported by the fluid flow. In addition, if the solid is considered as porous medium, the particles also enter the complex porous medium micro-structure. In this structure, chemical reaction occur, finally resulting in a morphological change of the porous medium.
In this talk, we focus on models describing the growth and shrinkage process and the micro-structural evolution. Hereby, for the sake of simplicity, we first propose an isothermal sharp-interface model, describing only the growth and shrinkage process. For this model, we discuss thermodynamic consistency and explain how it can be modified to a non-isothermal model. Afterwards, we will introduce a corresponding phase-field model and show, using asymptotic expansion series, that in the asymptotic limit of vanishing interface width, the model equations of the sharp-interface model are recovered. Furthermore, we also discuss thermodynamic consistency of the phase-field model and present some numerical results, showcasing how the phase-transformations are influenced by the chemical reaction laws.
Afterwards, we focus on a Stokes porosity model describing the microstructural evolution inside a solid porous medium. We up-scale this model in a periodic setting using expansion series and analyse how the effective diffusive transport inside the solid porous medium changes with respect to the scaling of the diffusion tensor in the Stokes porosity model.
Finally, we give a short outlook on how the up-scaling of the Stokes porosity model can be done rigorously and how growth and shrinkage processes can be introduced in this model.