Welcome to the Lattice Boltzmann Research Group
The Lattice Boltzmann Research Group (LBRG) is an interdisciplinary research group that aims to take advantage of novel mathematical modeling strategies and numerical methods to enable large-scale simulations and optimal control of fluid flows for applications in process engineering. The LBRG aims at a better fundamental understanding of suspensions in general and for the improvement of mechanical processes and medical treatments. In particular the LBRG designs and uses models, algorithms, and open source simulation tools such as OpenLB, always taking advantage of modern high performance computers for the simulation of, for example:
- Particulate fluid flows
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Thermal flows
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Turbulent flows
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Material transport and chemical reactive flows
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Light transport
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Fluid-structure interaction
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Flows in porous media and complex geometries
The LBRG’s teaching and education concept is project- and research-oriented, offering for example basic programming courses, lectures on parallel computing, software tutorials, and advanced seminars on particular fluid flow simulations as well as optimal control theory.
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Latest News
Our team members Shota Ito, Johannes Grafen, and Stephan Simonis from the Lattice Boltzmann Research Group (LBRG) Boltzmann Research Group (Karlsruher Institut für Technologie (KIT)) attended the 13th ICCFD: International Conference on Computational Fluid Dynamics (ICCFD13) in Milan, together with our research partner Arsh Kumbhat from the CAMLab at ETH Zurich!
In addition to attending inspiring talks and dynamic group sessions across a huge variety of CFD research fields, we had the great opportunity to connect with fellow researchers from around the world.
Overall, we contributed three talks:
- Generation of efficient adjoint lattice Boltzmann collision kernels with reverse mode algorithmic differentiation by Shota Ito
- Turbulent Fluid Flow Sampling with OpenLB-UQ by Johannes Grafen
- Probabilistic Lattice Boltzmann Methods for Statistical Solutions of Turbulent Flows by Stephan Simonis
A huge thank you to the local organizing committee, Alberto Guardone and Barbara Re, for hosting such a fantastic event at Politecnico di Milano!
We also want to express our gratitude to the DAAD Deutscher Akademischer Austauschdienst (German Academic Exchange Service) for the Conference Travel Program scholarship, funded by the Auswärtiges Amt (Federal Foreign Office) Germany. Thanks to the Conference Travel Program,
Shota, Johannes and Stephan were able to attend this international event and share their research.
The Lattice Boltzmann Research Group (LBRG) was thrilled to be part of the DSFD 2026 conference!
Florian Kaiser and Mathias Krause had the wonderful opportunity to showcase some of our most recent breakthroughs and advancements. We were proud to present our work focusing on:
- Tutorial on LBM for Applications by Mathias Krause
- Just-in-time CFD with LBM and OpenLB by Mathias Krause
- Structural Mechanics with the Lattice Boltzmann Method - towards monolithic FSI by Florian Kaiser
Beyond the academic sessions, a massive highlight for our group was the community engagement. It was a pleasure meeting bright new colleagues, sparking fresh ideas, and discussing the future of the field.
We were also incredibly happy to catch up in person with our fantastic project partners from M2P2 at the Aix-Marseille Université (AMU) working on the Falcon project. Collaborations like this drive our research forward, and it's always rewarding to celebrate our shared milestones face-to-face.
A huge thank you to Luis Hegele, Alexander Wagner, Jens Harting and the whole team for organizing DSFD 2026 and to everyone who stopped by our presentations or connected with us. We're heading back to the lab with plenty of inspiration!
The Lattice Boltzmann Research Group (LBRG) at Karlsruher Institut für Technologie (KIT) is proud to share our latest paper: “N-Component Free Energy Lattice Boltzmann Method with Reduction Consistency and Global Momentum Conservation”.
This work is the result of a collaboration by Michael Rennick, Xitong Zhang, Tim Niklas Bingert, Matthias J. Krause and Halim Kusumaatmaja.
This paper introduces a novel N-component free Energy Lattice Boltzmann Method, which adresses the long-standing issue of non-physical artifacts due to scale-up (N>=4) : absent fluid phases can spontaneously nucleate out of nowhere and numerical discretisation of errors in surface tension forces create artificial whole-domain momentum shifts. Our method manages to scale reliably to an arbitrary number of fluid phases by implementing an independent flux correction and a divergence-consistent force discretization.
Key Highlights from the Paper:
Reduction Consistency: Our framework ensures that absent fluid components do not unphysically appear, utilizing a flux correction in the Cahn-Hilliard equations that operates entirely independently of fluid mobility.
Machine Precision Conservation: By modifying the surface tension force implementation to align with a numerical divergence-consistent form, we eliminate unphysical whole-domain velocity drifts down to machine precision.
Arbitrary Fluid Phases: The model allows for the simulation of an arbitrary number of immiscible components (N>=4) in principle, with completely independent selection of all interfacial tensions.
Broad Impact: This robust framework unlocks high-fidelity engineering simulations for complex real-world applications, from targeted drug delivery in nested microfluidic emulsions to liquid-liquid phase separations in cell biology and smart anti-fouling coatings.
This paper is published open access and can be found here.
The picture shows the formation of an emulsion droplet from the injected fluids over time. The surface tensions are configured to encourage cloaking of fluids 3 (yellow) and 4 (blue) by fluid 2 (pink).