ENGINEERING AND CFD

Introduction

Gas flow through porous materials is crucial in various industrial and environmental systems, such as chemical reactors, filtration units, cooling systems, and natural environments. These materials, with void spaces called pores, create complex pathways for gas flow, especially under turbulent conditions. Researchers at the Chair of Thermal Turbomachines and Aeroengines used advanced numerical simulations to study these effects. They replicated industrial packed beds and used the SuperMUC-NG supercomputing system to model gas flow through structured arrays of particles. Their simulations enhance the current understanding of gas flow in porous media and impact the current mathematical models used to study such systems.

Report

Gas flow through porous materials plays a critical role in many industrial and environmental systems. These include chemical reactors filled with catalyst pellets, filtration and separation units, cooling systems, and natural environments such as forests or porous rock layers. Porous materials are naturally occurring or engineered solids with void spaces—pores—through which a gas can flow. Although gases are able to move freely in open space, their behaviour becomes far more complex when passing through or over dense arrangements of solid structures. 

When a gas flows through such media, it interacts with the solid structures in ways that are often unpredictable, as it is forced into tortuous pathways determined by the pore structure of a given porous substance. Complexity grows even greater in cases involving turbulence—a swirling, chaotic motion of the gas itself. Predicting how gases behave in such environments is essential for improving efficiency, reducing energy consumption, and ensuring safety across a range of applications.

To study these effects, researchers at the Chair for Thermal Turbomachines and Aeroengines of Ruhr University Bochum, developed and applied advanced numerical simulation techniques capable of resolving fine-scale details of turbulent flow through porous materials. The research activities were carried out by Wojciech Sadowski and Mohammed Sayyari, under the supervision of prof. Francesca di Mare. The main focus was placed on capturing the interaction between the gas in the free-flowing region above the porous material and the gas moving within the porous medium itself.

The research involved replicating a packed bed similar to those used in industrial chemical processes. Such an approach requires immense computation effort as both the geometrical complexity and the swirling flow features have to be accurately represented in the simulations. To fullfil this objective, the computing power of SuperMUC-NG supercomputing system was used in the context of the project „Effect of turbulence modeling on the fuel mixing and reaction in an array of cubes. Work in the context of Subproject C6, SFB/TRR287 BULK-REACTION” (id number: pn73gi).

In the simulated setup [1], gas was passed through a structured array of spherical particles. The numerical results were compared with experimental measurements using optical imaging methods. This allowed the researchers to validate their models and confirm that the simulations accurately captured the gas behaviour both inside the packed bed and in the region above it.