Seminar "Multi-scale modeling of large-scale gas-particle flows" by Dr. Stefanie Rauchenzauner

[Speaker]

Stefanie Rauchenzauner
Research Fellow, OIST
Postdoctoral Researcher, Johannes Kepler University Linz (JKU), Austria

[Abstract]

Gas–particle flows play an important role in various industrial and environmental processes. Numerical simulations of large-scale processes are essential for gaining insights into their design and optimization; however, they are computationally expensive due to the wide range of scales involved. On the particle scale, inter-particle collisions and interphase transfer terms must be resolved. Two-Fluid Models treat both phases as continua by modelling particle collisions through a transport equation for the granular temperature, analogous to the thermodynamic temperature. Together with suitable drag models, they can predict macroscopic flow behaviour on numerical grids about five times larger than the particle diameter. On coarser grids, however, meso-scale structures such as particle clusters and streamers are not resolved, leading to severe overestimation of interphase exchange terms.

We apply spatial averaging to derive closure models for the unresolved terms in coarse-grid Two-Fluid Model simulations. These models are based on the turbulent kinetic energy of both phases. An a posteriori evaluation shows good agreement with fine-grid simulations and experimental data.

[Biography]

Stefanie Rauchenzauner is a Postdoctoral Researcher at Johannes Kepler University Linz (JKU), Austria. She works on multi-scale modelling of multi-phase flows, with a focus on the efficient simulation of large-scale gas-particle flows. After earning her PhD at JKU, she conducted postdoctoral research on porous media flows at the Technical University of Munich (TUM). Currently, she investigates multi-phase turbulence in collaboration with Prof. Marco Edoardo Rosti at the Okinawa Institute of Science and Technology (OIST), supported by an Early-Stage Program Fellowship of the Austrian Science Fund.