KIT - LBRG News

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2026/04/20 - Computational Fluid Dynamics Lab (CFDS Lab) Are you interested in Computational Fluid Dynamics and High-Performance Computing? Come join our 𝗖𝗼𝗺𝗽𝘂𝘁𝗮𝘁𝗶𝗼𝗻𝗮𝗹 𝗙𝗹𝘂𝗶𝗱 𝗗𝘆𝗻𝗮𝗺𝗶𝗰𝘀 𝗮𝗻𝗱 𝗦𝗶𝗺𝘂𝗹𝗮𝘁𝗶𝗼𝗻 𝗟𝗮𝗯 during this 𝘀𝘂𝗺𝗺𝗲𝗿 𝘀𝗲𝗺𝗲𝘀𝘁𝗲𝗿 𝟮𝟬𝟮𝟲! If you want to learn the concepts of mathemtical modeling of PDEs, numerical simulation using Lattice Boltzmann Methods and high performance computing this course is for you. What’s the focus? We dive into the Lattice Boltzmann Methods (LBM) and talk about how to solve real-world transport phenomena in fluids and solids. You’ll work on diverse applications like, Chemical Reactors, Centrifugal Pumps, Aerodynamics/Airfoils and many more. The Toolkit Participants will get hands-on experience with the C++ software library OpenLB, and learn how to run simulations on High-Performance Computing (HPC) clusters. How it works The project are carried out in small groups, which will be supervised by doctoral students. Each group gives a short presentation to highlight specific results obtained during the course. Own project topic suggestions are welcome. This lab is funded by the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. More information can be found here: https://www.lbrg.kit.edu/cfdslab.php
2026/04/13 - New paper "In vivo blood viscosity estimation from microscopic images by solving an inverse incompressible Navier-Stokes problem" We are excited to announce the publication on in vivo blood estimation by Shota Ito, Moritz Vogel, Adrian A. Fessler, Adrian Kummerländer, Anna Lischke, Dietmar Gradl, Ferdinand le Noble, Mathias J. Krause and Stephan Simonis. This paper is motivated by the ongoing challenge of assessing in vivo blood viscosity, as most existing methods rely on simplified flow descriptions and have rarely been applied to real data. This limits bedside monitoring, cardiovascular risk stratification and the parametrization of patient-specific computational hemodynamic models. The concept of this paper is based on the developement of non-invasive framework (combining microvascular particle image velocimetry (micro-PIV) with computational fluid dynamics (CFD) to estimate the effective blood viscosity in vivo) and the usage of time-averaged velocity fields, which are reconstructed from high-speed microscopic image sequences of blood flow and are incorporated into an inverse formulation of the incompressible Navier-Stokes equations for an either Newtonian or non-Newtonian fluid and solved using full CFD simulations. As proof of this concept, the framework is applied to in vivo microcirculatory data obtained from zebrafish embryos, yielding effective viscosity estimates consistent with values reported in the literature. It hereby establishes an image-based, physics-constrained framework for blood rheology and provides a tool to improve parametrization and validation of computational hemodynamics models. The paper is published open access in the journal Computer Methods in Applied Mechanics and Engineering and is freely available at https://doi.org/10.1016/j.cma.2026.118927 .
2026/04/07 - New paper "Analytical solution for dynamic evaporation of liquid in isothermal condition" We are excited to announce the publication of our latest research on liquid-vapor phase transitions by Luiz Eduardo Czelusniak, Tim Niklas Bingert, Stephan Simonis, Alexander Wagner and Mathias J. Krause. This study is motivated by the need for deeper physical insights into evaporation phenomena, which are critical for engineering applications ranging from food drying to fuel injection systems in combustion engines. Key Findings: - Novel Viscosity Relationship: Our model unveils a previously unexplored dependence of evaporation rates on fluid viscosity, a behavior not captured by classical models. - Diffuse Interface Approach: By using a diffuse interface model, we eliminate the need for common assumptions like local equilibrium or jump conditions at the interface. - Exact and Approximate Solutions: We derived an exact analytical solution for the inviscid case and a highly accurate approximate solution for the viscid case. - Numerical Validation: The analytical results show excellent agreement with high-resolution Lattice Boltzmann Method (LBM) simulations performed using the open-source library OpenLB. The article is published in the journal Physical Review E (Open Access) and is freely available at https://doi.org/10.1103/4dl9-1x8s .
2026/04/03 - New paper "Pore-scale applications of Phase-field Lattice Boltzmann Methods for underground CH4, H2 and CO2 storage" We are excited to share our latest publication : “Pore-scale applications of Phase-field Lattice Boltzmann Methods for underground CH₄, H₂ and CO₂ storage” by Alice Raeli, Mathias J. Krause, Dario Viberti, Tim Niklas Bingert, Eloisa Salina Borello, Cristina Serazio, and Luiz Eduardo Czelusniak. This work explores advanced pore-scale modeling approaches, leveraging OpenLB, to better understand multiphase flow dynamics in Underground Gas Storage (UGS) systems. In this study, we present: - Simulation of drainage and imbibition processes in UGS - A complete workflow for Rock-on-a-Chip generation from 3D micro-CT images - Multiphase flow modeling using a Phase-Field LBM (Allen–Cahn approach) - Improved handling of high density and viscosity ratios via Smagorinsky-based relaxation time - Robust outflow boundary conditions These developments contribute to more reliable and efficient modeling of subsurface storage processes for CH₄, H₂ and CO₂. The paper is published open access in the Journal of Energy Storage and is freely available on https://doi.org/10.1016/j.est.2026.121868 .
2026/03/30- LBRG at HLRS for C++ Training Earlier this month, four members of our group spent an intensive week in March at the HLRS - Höchstleistungsrechenzentrum Stuttgart in Stuttgart participating in the intermediate C++ Course taught by Klaus Iglberger. Beyond a deep dive into advanced concepts of C++ and modern standards, it was a fantastic week of networking with fellow researchers from various fields. We’re returning to the lab not only with a more powerful programming toolkit, but also with fresh perspectives from the wider scientific computing community. We had a great time learning more about advanced topics in C++, which we are now excited to apply in our daily work. Many thanks to Klaus Iglberger and the HLRS - Höchstleistungsrechenzentrum Stuttgart for the great course!
2026/03/27 - The Spring School 2026 in Liverpool (UK) was a success What a great week at the University of Liverpool! Bringing together the LBM-community, with 42 participants from 11 countries for our 9th Spring School on Lattice Boltzmann Methods. We would like to thank our friends at University of Liverpool, John Bridgeman, Davide Dapelo and Mohaddeseh Mousavi Nezhad for hosting this year's Spring School, which allowed us to introduce and help so many people to the methods, theory and best practices of LBM. The spring school provides both an environment for learning and understanding LBM, but also for developing new and interesting research problems. Also a big thank you to Shota Ito, Tikhon Riazantsev, Mathias J. Krause and Stephan Simonis for organizing this year's OpenLB spring school. This years poster session allowed insights into the research of the LBM-community, showing off the huge range of different problems that are tackled using LBM. We would also like to congratulate Maxence Desnoyers on winning this years poster session with his poster on a "Numerical Framework to Study Structural Wetting Properties of Proton Exchange Membrance Fuel Cell Catalyst Layers". We would also like to thank this year’s invited speakers: Fedor Bukreev, Isabelle Cheylan, Davide Dapelo, Shota Ito, Florian Kaiser, Mathias J. Krause, Timm Krüger, Adrian Kummerländer, Halim Kusumaatmaja, Tim Reis, and Stephan Simonis. The preparations for next years spring school are already underway. It will take place from April 5-9 2027 in Erlangen, Germany. We are looking forward to seeing you there! Until then, stay tuned and happy research!
2026/03/23 - Visit of Prof.Dr. Siddhartha Mishra for the KIT Workshop: Data-driven methods for PDEs Last week, the LBRG team participated in the Workshop on Data-driven methods for PDEs at the Karlsruher Institut für Technologie (KIT) Department of Mathematics. We were honored to have Prof. Dr. Siddhartha Mishra, Head of the Computational and Applied Mathematics Laboratory (Camlab) and part of the ETH AI Center at ETH Zürich, deliver the opening presentation, titled "AI for Efficient Simulations for PDEs". We also had the opportunity to enjoy lunch together, where we exchanged research experiences and ideas. It is really inspiring to see how the combination of data-driven techniques, efficient numerical methods, and the constantly increasing computational power of HPC clusters is redefining the limits of scientific simulation. Stephan Simonis and Johannes Grafen presented some insights into their ongoing research on 'Exploratory computation of statistical Navier-Stokes solutions', during the poster session. The project is conducted in close collaboration with Prof. Dr. Siddhartha Mishra and his team. For this project Stephan Simonis is supported by the PRIME programme of the German Academic Exchange Service (DAAD Deutscher Akademischer Austauschdienst), with funds from the Federal Ministry of Research, Technology and Space (Bundesministerium für Forschung, Technologie und Raumfahrt). (https://lnkd.in/dVYktp_K) We sincerely thank Benjamin Unger, Martin Frank, Sebastian Krumscheid, Roland Maier, Nathalie Sonnefeld and Mathias Trabs for the organization of this workshop. It was a fantastic experience for the whole team!
2026/03/16 - LBRG Student presentations Our weekly LBRG Seminar provides a stage for our HiWis and thesis students to showcase their work. We recently enjoyed a fantastic round of presentations from our student members: - Luis Wittich, who currently working on his Master's thesis and presented the interim state. His thesis evolves around wall-modelled LES of the Taylor-Couette flow. - Michael Grinschewski, one of our student assistants, is developing a specialized indicator function to define airfoil profiles in OpenLB. - Maren Weber, also a student assistant, who manages our group’s digital presence, from LinkedIn posts to our annual LBRG Advent Calendar. Thanks to our student members for the great presentations!
2026/03/09 - Visiting Scientists at LBRG We are excited to welcome a group of visiting scientists to the LBRG! International exchange and collaboration are at the core of our research, and we are delighted to be hosting three researchers currently working with our team. We are joined by: • Flavia Zinani, Professor at the IPH-UFRGS (Federal University of Rio Grande do Sul), who is with us for a 6-month postdoctoral research stay. Flavia is focusing on developing simulations of wave-energy converters using OpenLB. • Leonardo Dorneles, a doctoral researcher from the Laboratory of Structural Bioinformatics and Computational Biology (SBCB), also here for a 6-month stay. Leonardo is working on the development and evaluation of optimization methods for massively parallel architectures and distributed computing environments. Their visit is supported by the collaborative project between Federal University of Rio Grande do Sul and Karlsruher Institut für Technologie (KIT): 'MCTI/CNPq 16/24 - Computational Fluid Dynamics and Machine Learning for Sustainable Engineering.' We also recently hosted Alisdair Soppitt from the University of Liverpool for a productive month-long research stay in February. Alisdair worked on applying our resolved particle code in OpenLB to simulate the clogging of porous asphalt by particulate matter. It is a pleasure to collaborate with such talented researchers. We look forward to the continued impact of these joint efforts on our ongoing projects!
2026/02/23 – New research staff member: Johannes Grafen joins the LBRG We are excited to share that Johannes Grafen has joined our team as a new doctoral researcher back in November. His research focuses on Gradient-based Optimization (GBO) with LBM and Uncertainty Quantification (UQ). He started his academic career at RWTH Aachen University, where he completed his Master’s degree in Simulation Sciences and his Bachelor’s degree in Mechanical Engineering with a specialization in Aeronautical Engineering. Welcome to the team, Johannes!
2026/02/16 — Project Visit: myEnspect (investBW) We were delighted to host Johannes Klatte and Matthias Wagner from IDR-Solutions GmbH for our collaborative project, myEnspect. It was a productive day focused on project updates and brainstorming new conceptual ideas. Beyond the technical sessions, we enjoyed great conversation, a tasty lunch, and a fantastic atmosphere. It’s always inspiring to exchange perspectives and shape future research directions together. Looking forward to the next steps and our continued collaboration!
2026/02/09 – New project: The "Beyond 15-minute Cities" As climate change intensifies, the "15-minute city" concept, reliant on walking and cycling, is being challenged by extreme heat that can render outdoor mobility hazardous. Our new project "Beyond 15-Minute Cities" addresses this gap by developing new simulation capabilities. Current microclimate modeling is computationally prohibitive for city-scale thermal comfort analysis. This project aims to enhance the existing OpenLB simulation framework with automatic geometry-adjusted mesh refinement targeted specifically at urban flows. This will enable high-resolution thermal comfort analysis across entire urban areas while maintaining accuracy in critical pedestrian zones. The objective is to quantify how rising temperatures impact walkability thresholds and develop evidence-based guidelines for climate-adaptive neighborhoods. An interactive decision-support tool will help planners optimize the distribution of essential services, cooling infrastructure, and green networks. This collaboration (Karlsruher Institut für Technologie, Henning Larsen, Nflection) partners with C40 Cities to equip planners with essential data for designing climate-resilient communities.
2026/02/02 - Lattice Boltzmann Simulation of Lauric Acid Melting in Rectangular Cavity With Different Fin Configurations With OpenLB We are pleased to share this recent study about Latent heat energy storage systems (LHESS) using phase change materials (PCMs), which offer high thermal energy storage density and effective temperature regulation due to their ability to absorb and release heat at nearly constant temperatures. However, accurately simulating the melting process of PCMs remains challenging due to the nonlinear nature of heat transfer and phase transition mechanisms. In this study, the Lattice Boltzmann Method (LBM), implemented via the OpenLB framework, is employed to simulate the melting behavior of lauric acid material inside a finned rectangular cavity. The primary objective is to validate a new OpenLB numerical model against benchmark experimental data. The simulation results show excellent agreement with experimental observations in terms of liquid fraction evolution over time, particularly for the case with higher spatial and temporal resolution. Additionally, temperature measurements obtained from thermocouples at multiple locations within the cavity display the same trend in temperature evolution as observed in the numerical model, further supporting the model's reproducibility. Following validation, the model is used to study 12 additional configurations involving variations in fin aspect ratio and position. The simulations reveal that longer, thinner fins placed near the bottom of the cavity can reduce the total melting time. Between the minimum and maximum melting times obtained in this study, the fin aspect ratio and position showed a difference of 63.7%. Compared to upper fin placements, lower-position fins consistently maintained increased melting rates, with improvements ranging from 11% to 26% depending on the fin aspect ratio. In fact, higher melting rates were observed in longer and thinner fins for all positions studied, with improvements ranging from 1% to 25% depending on the position. Authors: Alexandre Tacques, Tim Niklas Bingert, Adrian Kummerländer, Luiz Eduardo Czelusniak, Mathias J. Krause, Marcio Dorn Youtube Video: https://www.youtube.com/watch?v=IiPDLxNIRPs Read the full paper here: https://lnkd.in/dgsk5XSf
2026/01/19 – Guest visit of Dr. Eng. Luiz Hegele Jr. This December, the LBRG had the pleasure of hosting Dr. Eng. Luiz Hegele Jr., Associate Professor at the Universidade do Estado de Santa Catarina (UDESC), Brazil, for a three-day visit in Karlsruhe. He presented an insightful talk titled “Moment Representation in the LBM: Boundary Conditions and Complex Flows”, offering valuable insights into his group’s ongoing research. With our teams working on closely related topics, the visit sparked productive discussions and a fruitful exchange of ideas. We look forward to reconnecting later this year at the International Conference on Discrete Simulation of Fluid Dynamics (DSFD) in Balneário Camboriú, Brazil, which he will co-host. Thank you for visiting, Luiz - it was a pleasure having you!
2026/01/12 – New research staff member: Tikhon Riazantsev joins the LBRG We are pleased to announce that Tikhon Riazantsev has joined our team as a new doctoral student back in October. His research concerns multiphase flow simulations using the lattice Boltzmann method, focusing on thermodynamically consistent phase-change modelling. Before starting his doctoral research at the Lattice Boltzmann Research Group at KIT, he completed his Master's degree in Biomedical Engineering at the Universität zu Lübeck and his Bachelor's degree in Mechanical Engineering with a specialization in Hydraulics at the Bauman Moscow State Technical University. Welcome to our team, Tikhon!
2026/01/05 - LBRG at the 15th conference of the European Aerospace Science Network (EASN) Back in October, LBRG members Fedor Bukreev and Adrian Kummerländer visited the 15th conference of the European Aerospace Science Network (EASN) on Innovation in Aviation & Space towards sustainability today and tomorrow in Madrid (https://easnconference.eu/). Alongside other partners of the EU Horizon project FALCON (https://falconproject.eu/), they presented talks on efficient wall-modeled large eddy simulations for fluid-structure interaction as well as the automatic code generation of adjoint lattice Boltzmann methods for these simulations.
2025/12/29 - Throwback to the Annual OpenLB Hackathon For the second time, more than twenty OpenLB developers retreated to the mountains for their annual Hackathon. There, they spent one week fully focused on improving the framework, exchanging knowledge and enjoying nature. This time, the focus was on refactoring all 138 example cases into a new consistent and user-friendly case style as well as general maintenance for the release of OpenLB 1.9 . The LBRG was joined in the Naturfreundehaus Badener Höhe (Forbach, Black Forest) by external contributors Arsh Kumbhat (ETH Zürich), Philipp Spelten (Universität Siegen), Gagan Deep Prakash (Offenburg University of Applied Sciences) and Andreas Schneider (Offenburg University of Applied Sciences).
2025/11/17 - CFDS Lab organized by LBRG visits HoreKa supercomputer at SCC/KIT As part of this year's Computational Fluid Dynamics and Simulation (CFDS) Lab Course, the LBRG organized an excursion to the HoreKa supercomputer at SCC, KIT. The excursion marks the completion of an inspiring summer term with 38 registered participants from Engineering, Mathematics and Computer Science programs. The CFDS Lab is offered by a funded collaboration between the Lattice Boltzmann Research Group and the Scientific Computing Center (https://www.scc.kit.edu/): Stephan Simonis, Mathias J. Krause, Gudrun Thaeter, Jasmin Hörter, and Martin Frank. In the course, we enable students to efficiently use the large-scale computing infrastructures at KIT such as HoreKa for scientific simulations with highly efficient codes such as OpenLB. This course is funded by the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. More information on is available here We gratefully acknowledge the computing time for our course provided on the high-performance computer HoreKa by the National High-Performance Computing Center at KIT (NHR-Verein, NHR-Alliance Karlsruhe Institute of Technology (KIT)). This center is jointly supported by the Federal Ministry of Education and Research and the Ministry of Science, Research and the Arts of Baden-Württemberg, as part of the National High-Performance Computing joint funding program.HoreKa is partly funded by the German Research Foundation.
2025/11/10 - With SeaDream in Liverpool Over the past four weeks, four members of LBRG visited the University of Liverpool as part of the European Project SeaDream. - Mathias J. Krause gave several presentations to colleagues in Liverpool, Manchester, Cardiff, and Sheffield - We planned the upcoming Spring School 2026 in Liverpool - Work on our first project paper on fluid structure interaction made great progress. A big thanks you to our partners at Liverpool, Mohaddeseh Mousavi Nezhad, Davide Dapelo and John Bridgeman, for their warm welcome and inspiring discussions – we’re looking forward to the next steps in SeaDream!
2025/11/03 - LBRG and Prof. Dr. Marcio Dorn visited Dr. Pedro Narloch at paretos in Heidelberg We’re proud to share that Dr. Pedro Henrique Narloch, a recent alumnus of UFRGS under the supervision of Prof. Dr. Marcio Dorn and a frequent visitor LBRG, has joined paretos as a Machine Learning Engineer. Paretos is a provider of cutting-edge AI-technology for controlling complex processes, based in Heidelberg. In August, Marcio Dorn and Mathias J. Krause Krause visited Pedro Henrique Narloch at paretos and discussed further opportunities for continuing joint interdisciplinary projects such as the successfully completed DAAD-funded ProBral initiative on Mesoscopic Molecular Dynamics Simulations. We wish you all the best in your new role, Pedro Henrique Narloch!
2025/10/27 - Guest visit of Prof. Dr. Marcio Dorn at LBRG In August, we had the pleasure of welcoming Prof. Dr. Marcio Dorn (SBCB Lab at UFRGS, Brazill, https://sbcb.inf.ufrgs.br/) at LBRG. The longstanding Brazil-German collaboration between Mario Dorn and Mathias J. Krause Krause at LBRG has resulted in numerous staff exchanges at all academic career levels as well as workshops, publications and successful projects on Lattice Boltzmann Methods, Machine Learning, High-Performance Computing and cross-disciplinary fields of application. This time, the project group planned future research collaborations and prepared the upcoming guest visits of expert scientists from SBCB Lab at LBRG in 2026. We look forward to continuing the fruitful collaboration with Marcio Dorn and the SBCB Lab at UFRGS.
2025/10/20 - LBRG at Cardiff University In September, Mathias had the pleasure to visit his alma mater Cardiff University / Prifysgol Caerdydd, where he was studying as an Erasmus scholar more than 20 years ago. He renewed and intensified his contacts to Emeritus Professor of Mathematics Tim Phillips and Reader in the School of Engineering Zhihua Xie. Besides research around Lattice Boltzmann Methods (LBM) and its applications, the organization of future collaborations were discussed as well as a revival of undergraduate student exchange programs. Thank you, Cardiff — it was good to be back!
2025/10/13 - CFDS Lab organized by LBRG visits wind tunnel at IWU KIT As part of this year's Computational Fluid Dynamics and Simulation (CFDS) Lab Course, the LBRG organized an excursion to the wind tunnel at the Laboratory of Building and Environmental Aerodynamics at IWU, KIT. Dr. Christof Gromke and his team have guided the participants through the testing facilities and introduced fundamental concepts and research milestones of their lab. The CFDS Lab is offered by a funded collaboration between the Lattice Boltzmann Research Group and the Scientific Computing Center (https://www.scc.kit.edu/): Stephan Simonis, Mathias J. Krause, Gudrun Thaeter, Jasmin Hörter and Martin Frank. In the course, we enable students to efficiently use the large-scale computing infrastructures at KIT such as HoreKa for scientific simulations with highly efficient codes such as OpenLB. This course is funded by the Federal Ministry of Education and Research (BMBF) and the Baden-Württemberg Ministry of Science as part of the Excellence Strategy of the German Federal and State Governments. Learn more
2025/10/06 - Final HighVis Projcet Meeting at LBRG In August, the LBRG had the pleasure of welcoming Prof. Dr. Ferdinand le Noble and Dr. Dietmar Gradl from the Zoological Institute at KIT for the final HighVis project meeting. The multidisciplinary HighVis project is funded by a ZEISS Collaboration Catalyst grant initiated by ZEISS Group and Karlsruher Institut für Technologie (KIT) and aligns with the research goals of the KIT Center Health Technologies . In this project we propose a novel approach to measure blood viscosity based on in vivo intravital microscopic imaging of dynamic blood flows in the microcirculation, and subsequent computational analysis of microcirculatory red blood cell behavior. Blood viscosity is an independent risk factor for predicting cardiovascular diseases including heart infarct and stroke. Routine assessment of blood viscosity can prevent progression to organ failure and subsequent premature mortality.Currently, fast, non-invasive techniques allowing repetitive measurement of viscosity in relevant patient populations are lacking, whereas existing ex-vivo techniques are cumbersome and not suitable for regular diagnostics.Our new algorithms developed in HighVis efficiently solve an inverse problem based on non-Newtonian Navier-Stokes models and deliver blood dynamics characteristics including viscosity. A big thank you to the project group, Shota Ito, Ferdinand le Noble, Dietmar Gradl, Mathias J. Krause, and Stephan Simonis and our collaboration partners Gerd Klose, Ali Fard, Christian Kungel, and Sophia Schmitt, for their contributions and insights throughout this exciting project! Stay tuned for upcoming publications and follow-up initiatives building on this work.
2025/09/29 - Meeting for the new VDMA project On August 28th, LBRG visited ITT Rheinhutte Pumpen GmbH (www.rheinhuette.de) preparing the official start of a new VDMA project, in which LBRG and HS Offenburg will jointly develop LBM-based simulation tools for high-fidelity centrifugal pump calculations. We were pleased to meet our project partners: Prof. Andreas Schneider from HS Offenburg, Dr.-Ing. Heiko Kipp from ITT Rheinhütte Pumpen GmbH, and Harald Frank from VDMA. As part of the meeting, we had the opportunity to tour ITT Rheinhütte Pumpen GmbH’s production facilities and discuss the initial steps of the project. We look forward to this collaboration and to developing a state-of-the-art design instrument for next-generation pump technologies together with our partners.
2025/09/22 - New paper on Optimization of single node load balancing Adrian Kummerländer, Fedor Bukreev, Dennis Teutscher, Marcio Dorn and Mathias J. Krause have published a new paper on the Optimization of single node load balancing for lattice Boltzmann method on heterogeneous high performance computers in the Journal of Parallel and Distributed Computing (JPDC). While LBMs are particularly suited for highly parallel computational fluid dynamics simulations on heterogeneous HPC systems, the computationally dominant collide-and-stream loops commonly utilize only GPUs, leaving CPU resources underutilized. To overcome this limitation, this article proposes a novel load balancing strategy based on a genetic algorithm for bottom-up, cost-aware optimization of spatial domain decompositions. This approach generates subdomains and rank assignments inherently suited for cooperative execution on both CPUs and GPUs. Implemented in the open source framework OpenLB, the strategy is applied to turbulent flow reference cases, including a multi-physics reactive mixer. A detailed evaluation on heterogeneous HPC nodes demonstrates significant performance gains, achieving speedups of up to 87% compared to traditional GPU-only execution. This work therefore establishes cost-aware, bottom-up decomposition as a suitable strategy for exploiting the native heterogeneity of modern compute nodes.
2025/09/15 - New Team Member We are delighted to welcome our new PhD student, Florian Kaiser, to the group. His research will focus on solving transport problems in process engineering using monolithic approaches, with a particular emphasis on the development and implementation of a monolithic FSI solver.
2025/08/25 - New Paper published on the consistency of pseudo-potential lattice Boltzmann methods We present a rigorous analysis of the pseudo-potential lattice Boltzmann method (P-LBM), showing its convergence to a PDE under diffusive scaling. By linking model parameters directly to physical properties, we enable simulations with inputs in SI units—no empirical tuning required. The method is implemented in OpenLB and validated with R134a benchmark tests. Learn more
2025/07/28 - ICMMES 2025 conference From July 21-25, 2025, Mingliang Zhong attended the ICMMES 2025 conference in Wuhan, China. He presented his work on “Non-Intrusive and Intrusive Uncertainty Quantification for Lattice Boltzmann Method,” showcasing recent developments in UQ methods integrated with OpenLB. He also contributed a poster introducing OpenLB and its role in advancing CFD research and education. A highlight of the event was a discussion with Zhaoli Guo, a leading expert in the LBM community.
2025/07/21 - New Paper on a Digital Twin of a City We are pleased to announce our new paper, “A digital urban twin enabling interactive pollution predictions and enhanced planning,” was published in the journal Building and Environment. This work was made possible through the contributions of Dennis Teutscher, Fedor Bukreev, Adrian Kummerländer, Stephan Simonis, Peter Bächler, Ashkan Rezaee, Mariusz Hermansdorfer, and Mathias J. Krause. This paper presents a novel approach for developing a digital twin of a city. By leveraging the computational power of GPUs in combination with the OpenLB simulation software, it becomes possible to dynamically update simulations using meteorological data such as wind speed, wind direction, and pollution levels. This enables real-time observation of pollutant dispersion and airflow patterns. The integration of automated geometry generation from OpenStreetMap data further allows the system to be adapted to various urban environments and scenarios. This approach provides valuable support for advanced urban planning and decision-making by architects and policymakers. You can read the full paper here: https://www.sciencedirect.com/science/article/pii/S0360132325005748
2025/07/21 - New paper on consistency of lattice Boltzmann methods published in ESAIM: M2AN Stephan Simonis and Mathias J. Krause have published a new paper entitled "Limit consistency of lattice Boltzmann equations" in the ESAIM: M2AN journal. The work establishes the notion of limit consistency as a modular part in proving the consistency of lattice Boltzmann equations with respect to a given partial differential equation system. Here, the incompressible Navier–Stokes equations are used as a paragon. Based on the hydrodynamic limit of the Bhatnagar–Gross–Krook (BGK) Boltzmann equation towards the Navier-Stokes equations, a successive discretization is proposed by nesting Taylor expansions and finite differences. As a direct result, the discretization technique of lattice Boltzmann methods is unfolded as chaining finite differences which provides a generic top-down derivation leading to the final numerical scheme. The paper is available open access at https://www.esaim-m2an.org/articles/m2an/abs/2025/03/m2an240044/m2an240044.html
2025/07/14 - Simulating Water Flow in an Hourglass with OpenLB We are excited to present this student project by Maximilian Schecher (supervised by Adrian Kummerländer), which demonstrates free surface flow using the Lattice Boltzmann Method (LBM) within the open-source framework OpenLB. The Video can be seen here: https://www.youtube.com/watch?v=PTT3mbFTjg8 For further information: https://openlb.net
2025/06/30 - New Paper on Predicting Filter Medium Performance We are pleased to announce that our new paper, “Predicting Filter Medium Performances in Chamber Filter Presses with Digital Twins Using Neural Network Technologies”, was published in the journal Applied Sciences. This work was made possible through the contributions of Dennis Teutscher, Tyll Weber-Carstanjen of the company SIMEX, Stephan Simonis and Mathias J. Krause. In this paper, a novel approach to optimize the operation of chamber filter presses through digital twins powered by machine learning is presented. By leveraging sensor data and neural network models, we can accurately forecast key performance indicators such as pressure and flow rates, even in partially or completely unknown scenarios. This advancement enables more efficient process monitoring, reduces downtime, and supports sustainable operation in solid-liquid separation processes. The full paper is available open-access here: https://www.mdpi.com/2076-3417/15/9/4933
2025/06/23 - Welcoming our guest Prof. Dr. Martin Geier We are honored to welcome Prof. Dr. Martin Geier from TU-Braunschweig. Martin is visiting us for a presentation on “Types of orthogonality in the Lattice Boltzmann Method with multiple relaxation rates”. We sincerely thank Martin for his time and effort and look forward to future collaborations!
2025/06/02 - Successful PhD defense of Oliver Boolakee at ETH Zürich On April 30, 2025, Dr. Oliver Boolakee successfully defended his PhD thesis on "Lattice Boltzmann for Solids" at ETH Zürich. In his groundbreaking thesis, he proposed new second-order accurate lattice Boltzmann formulations for linear elasticity, considering both static and dynamic problem formulations. PD Dr. Mathias J. Krause, heading the LBRG at KIT, served as a co-examiner in the doctoral committee alongside Prof. Dr. Laura de Lorenzis (ETH Zürich), Prof. Dr. Barbara Wohlmuth (TU Munich), Prof. Dr. Martin Geier (TU Braunschweit) and Prof. Dr. Ralf Müller (TU Darmstadt).
2025/05/19 - Visit at PSI On the 8th of April, Mathias J. Krause and Fedor Bukreev from LBRG visited the Paul Scherrer Institute (PSI), where they presented recent LBM and OpenLB developments to Dr. Nikolaos Prasianakis and his group (Laboratory of Waste Management). The focus of the discussion was on microfluidics and flows in porous materials. LBRG looks forward to intensifying further cooperation with PSI.
2025/05/12 - DECHEMA Specialist Group Meeting on Particle Technology From the 25th to the 27th of March, Mathias J. Krause and Christoph Gaul attended this year's DECHEMA specialist group meeting on particle technology at the Technical University of Clausthal. Christoph gave a presentation about the regeneration of wall-flow filters, which is part of a DFG project and was primarily worked on by Nicolas Hafen (doi:10.1017/jfm.2023.35). Clausthal was a very pleasant location for the conference. While remote, it is a beautiful city with a fascinating history, having been an important center for mining for several centuries. The technical university remains deeply rooted in this field of expertise. We attended several presentations on particle modelling and CFD. There were many interesting talks and posters from other groups working on particle simulations. We also visited SympaTec, a local company specializing in particle measurement, and discussed potential collaboration on an upcoming project.
2025/05/05 - New paper "Homogenized lattice Boltzmann methods for fluid flow through porous media – Part I: Kinetic model derivation" published in ESAIM: Mathematical Modelling and Numerical Analysis (M2AN) We are excited to announce the publication of our article "Homogenized lattice Boltzmann methods for fluid flow through porous media – Part I: Kinetic model derivation" in the esteemed open-access journal ESAIM: Mathematical Modelling and Numerical Analysis (M2AN). In our paper, we establish homogenized lattice Boltzmann methods (HLBM) for simulating fluid flow through porous media. Our contributions in this first part are twofold. First, we assemble the targeted partial differential equation system by formally unifying the governing equations for nonstationary fluid flow in porous media. Second, we propose a kinetic model, the homogenized Bhatnagar–Gross–Krook Boltzmann equation, which approximates the homogenized nonstationary Navier–Stokes equations (NSE). We formally prove that the zeroth and first order moments of the kinetic model provide solutions to the mass and momentum balance variables of the macroscopic model up to specific orders in the scaling parameter. The article is published open-access in the ESAIM M2AN journal here Based on the present paper, in the sequel (Part II appearing soon), the homogenized NSE will be consistently approximated by deriving a limit-consistent HLBM discretization of the homogenized Bhatnagar–Gross–Krook Boltzmann equation, and numerical limits will be explored based on efficient implementations in OpenLB
2025/04/28 - Showcase: Optimizing Underground Fluid Storage As a result of a five-month collaboration, we provide an example of a simulation on underground fluid storage using OpenLB, an open-source lattice Boltzmann method (LBM) software. One of the main challenges in subsurface fluid dynamics is dealing with complex rock structures and high-density ratio differences. In our study, we simulate gas (red) (hydrogen, methane, and CO2) displacing water (blue) in a real rock micro-fluidic device to analyze how underground formations can be optimized for fluid storage. Key parameters of the presented simulation: - Hydrogen injection into water-filled porous media - Density ratio: 7.1 kg/m³ (H2) vs. 992 kg/m³ (H2O) - Device size: 2 cm x 1 cm - Pressure drop: 120 Pa - Contact angle: 30° - Resolution: 8.3448e-06 m Our LBM D2Q19 phase-field multi-phase model is based on the Allen-Cahn approach, allowing for accurate tracking of phase interfaces and capillary effects. This research, developed at Politecnico di Torino within the iENTRANCE project and partially implemented at the KIT Institute in collaboration with the OpenLB team, provides valuable insights into hydrogen storage and geological sequestration. Special thanks to Mathias J. Krause, Tim Bingert, and Luiz Eduardo Czelusniak for their contributions to the implementation and development of this work. The presentation will be held on April 10th at 9:00 AM during the OMC Med Energy 2025 conference in Ravenna. Raeli, A. et al. (2025). OMC Med Energy 2025 Ravenna. In Press, 8-10 Apr 2025.
2025/04/21 - LBRG contributes to SIAM CSE 2025 in Fort Worth, Texas In March, Dr. Stephan Simonis presented a talk at the SIAM Conference on Computational Science and Engineering (CSE) in Fort Worth, Texas, US. His talk on "Exploratory Computation of Statistical Solutions to Incompressible Fluid Flows" marks the starting point of a recently funded project in the DAAD PRIME program in collaboration with CAMLab at ETH Zürich . Within this project, the integration of efficient uncertainty quantification methods in OpenLB will enable the computation of time-dependent statistical solutions to boundary value problems described by Navier-Stokes and Euler models for turbulent fluid flow in three dimensions. Learn more
2025/24/03 - Showcase:Cross Flow Filtration We are pleased to present the simulation of dynamic Cross-Flow Filtration using OpenLB, an open-source lattice Boltzmann method (LBM) software. One problem in filtration is the blocking of the filter by particles that deposit on the membrane (membrane fouling). This leads to a decrease in performance of the filter. To prevent the formation of a fouling layer, a flow tangential to the membrane is induced in cross-flow filtration. This can be achieved by a rotor. In a project at KIT this dynamic cross-flow device has been tested for the purification of proteins, since a high disperse phase fraction can be achieved. Learn more at https://www.openlb.net/cross-flow-filtration/ or watch the YouTube video explaining the simulation at https://www.youtube.com/watch?v=Msh2iyG6-ho.
2025/03/17 - Dissertation on Suspension Dynamics We are pleased to announce the successful defense of the dissertation by Mr. M. Sc. Jan Eric Marquardt, titled: "Modeling and Simulation of Suspension Dynamics Capturing Shapes and Contacts – With Applications" Jan's outstanding scientific work was awarded the highest distinction, summa cum laude, in recognition of his exceptionally rigorous methodology, demonstrated interdisciplinary creativity, and, in particular, the sustainable and transparent implementation of his approch in the open-source software OpenLB (www.openlb.net). His research has resulted in six first-author and five co-author publications. Notably, one of his recent papers was published in the prestigious journal Computer Physics Communications (Impact Factor: 7.2, Impact Factor7,2 --Marquardt, J. E., Hafen, N., and Krause, M. J. “A novel model for direct numerical simulation of suspension dynamics with arbitrarily shaped convex particles.” In: Computer Physics Communications 304 (2024), p. 109321. DOI:10.1016/j.cpc.2024.109321). We warmly congratulate Dr.-Ing. Jan E. Marquardt on this remarkable achievement! Learn more
2025/10/03 - New Paper on Potential for damage to fruits during transport through cross-section constrictions We are excited to announce a new paper, written by Jan E. Marquardt, Bastian Eysel, Martin Sadric Cornelia Rauh and Mathias J. Krause on the damage to fruits during transportation. Fruit preparations are used in various forms in the food industry. For example, they are used as an ingredient in dairy products such as yogurt with added fruit. The dispersed fruit pieces can be described as soft particles with viscoelastic material behavior. The continuous phase is represented by fluids with complex flow behavior depending on the formulation. Characterization has shown that the fluids exhibit a yield stress and pseudoplastic behavior, which can be described by the Herschel–Bulkley model. The analysis is performed numerically using the homogenized lattice Boltzmann method and validated by an experiment on industrial fruit preparations at pilot plant scale. The results show a strong dependence of the damage potential on the (local) Metzner–Reed Reynolds number. Learn more
2025/02/17 - Showcase: Protein Separation We are excited to present a simulation on Protein Separation using OpenLB, an open-source lattice Boltzmann method (LBM) software. One of the main problems in biotechnological production of active pharmaceutical ingredients is the separation of protein. Protein is dissolved in water and therefore difficult to remove. In an innovative method, developed by researchers of KIT, the protein absorbs at functionalized carrier particles. Learn more at https://www.openlb.net/protein-separation/ or watch the YouTube video of the simulation at https://www.youtube.com/watch?v=i6mHgKJM1FQ .
2025/02/10 - Further Cooperation with the Brno University of Technology We are happy to announce that we will extend our cooperation with Frantisek Prinz, Frantisek Lizal and many more from the Brno University of Technology. In March we first published a paper on paper on Comprehensive experimental and numerical validation of Lattice Boltzmann fluid flow and particle simulations in a child respiratory tract. Now we aim to study particle transport and deposition within the human respiratory system. This is essential for understanding various physiological and pathological processes as well as for developing effective drug delivery strategies. While considerable research has focused on male airway models, there is a growing recognition of the need to investigate female-specific airway geometries due to significant anatomical and physiological differences between sexes. Learn more
2025/02/10 - Welcoming our guest Yongbo Deng We are honored to welcome Yongbo Deng from Institute of Microstructure Technology (IMT) Yongbo Deng is visiting us for a presentation on Topology Optimization of Micro and Nano Structures, which introduces a theoretical method for the development of Highly lightweight structures. This technique has numerous applications, metalenses in visible and infrared light, metalens arrays and many more. We sincerely thank Yongbo Deng for his time and effort and look forward to future collaborations!
2025/01/20 - Official Start of the SeaDream Project The SeaDream project strengthens EU efforts to achieve climate neutrality and to meet green energy and environmental targets. SeaDream plays a crucial role in ensuring that marine energy is used sustainably and that coastal environments are preserved in line with EU policies. The development of a high-resolution water-quality data service at sea is at the core of SeaDream’s mission. Data like these are crucial for addressing specific questions regarding maritime renewable energy generation and storage. In cooperation with the University of Luxembourg, the University of Liverpool, and several other partners, the Lattice Boltzmann Research Group (LBRT) at KIT will work on this project for four years. Video of a Large Eddy Lattice Boltzmann Simulation of a Wind Park is available here: https://www.youtube.com/watch?v=dCAQiXfV50I Learn more
2024/12/09 - Welcoming our new research staff member: Christoph Gaul We are pleased to announce that Christoph Gaul has joined our team as a new research staff member. His main topic of research will be Modelling ans Simulation of Particulate Flows. More percisely development of models and numerical methods for the simulation of particulate, turbulent and reactive flows for process engineering applications.
2024/12/02 - Welcoming our guest Philipp Spelten We are honored to welcome Philipp Spelten from the University of Siegen at the Lattice Boltzmann Research Group (LBRG) at KIT. During his visit, Philipp worked on aeroacoustics and noise prediction for airfoils with Lattice Boltzmann Simulations in OpenLB.We would like to thank Philipp for his time and effort. We are looking forward to future collaborations.
2024/11/21 - New paper “Benchmark Simulation of Laminar Reactive Micromixing Using Lattice Boltzmann Methods” in American Institute of Aeronautics and Astronautics Journal published We are excited to announce the publication on “Benchmark Simulation of Laminar Reactive Micromixing Using Lattice Boltzmann Methods” in the American Institute of Aeronautics and Astronautics Journal. There, we reestablish a benchmark for a reactive laminar micromixer using lattice Boltzmann methods (LBM) with special treatment of specie transport in secondary vortices resolved till the smallest Batchelor scale. This research was done with help of the open source CFD software OpenLB. The article is published in the AIAA Journal under subscription: https://doi.org/10.2514/1.J064234 and is freely available as preprint at https://dx.doi.org/10.13140/RG.2.2.10086.64326
2024/11/21 - New paper “Calculation of Single and Multiple Low Reynolds Number Free Jets with a Lattice-Boltzmann Method” in American Institute of Aeronautics and Astronautics Journal published We are excited to announce the publication on “Calculation of Single and Multiple Low Reynolds Number Free Jets with a Lattice-Boltzmann Method” in the American Institute of Aeronautics and Astronautics Journal. In this research, we investigated behavior of a free jet and free jets bundle at distinct Reynolds numbers using lattice Boltzmann method and OpenLB. The article is published in the AIAA Journal under subscription: https://doi.org/10.2514/1.J064280
2024/10/23 - First OpenLB Hackathon completed From October 6-11, 2024, the LBRG successfully organized the first OpenLB Hackathon in Feldberg, Germany. For one week, 14 group members focused on core development to further improve OpenLB in terms of boundary condition modeling, GPU support and user friendliness.
2024/08/25 - New paper on UQ and LBM published in Journal of Computational Physics For the first time, we combined the lattice Boltzmann method (LBM) with the stochastic Galerkin (SG) method. The article is published open access in the Journal of Computational Physics and is freely available at https://doi.org/10.1016/j.jcp.2024.113344 . SG LBM extends LBM into the field of uncertainty quantification. As a proof of concept, we implemented parts of the approach in OpenLB and validated it using classical fluid dynamics benchmark tests with multidimensional uncertainty. In our numerical experiments, we achieved a speedup factor of 5.72 compared to Monte Carlo sampling, which demonstrates the high efficiency of SG LBM.
2024/07/18 - Block seminar on computational fluid dynamics The lectures in the block seminar on computational fluid dynamics took place this week. Topics included particle distribution in the air after coughing, boiling water in microchannels, wind simulations around individual buildings and in residential neighbourhoods with different tree cover (in Dubai). We studied models with compressibility, with springs and for non-spherical particles. On Monday, 22 July at 1 pm, we will present the topics for next semester's seminar in room 3.069.
2024/07/15 - New Video on our upcoming Fluid Structure Interaction module We have just released a new video on our OpenLB YouTube Channel. This is a first experimental showcase of OpenLB’s upcoming general purpose fluid structure interaction (FSI) capabilities. Visualized are various viewpoints on the vorticity norm of a two-way coupled four-turbine wind park setup with Reynolds number 1.2 Million. The simulation consisting of 1.5 billion cells utilized a single accelerated compute node of 4x NVIDIA H100 GPGPUs. Computed on HoreKa Teal at KIT, the world’s sixth most energy efficient supercomputer. Simulation & Visualization by Adrian Kummerländer Visualization was generated in ParaView.
2024/07/08 - Prof. Dr. Alexander Wagner visited the LBRG Last Friday (05.07.2024), the members of the Lattice Boltzmann Research Group (LBRG) received Prof. Dr. Alexander Wagner. His visit was marked by excellent research exchanges on Lattice Gas and Boltzmann Methods.
2024/06/17 - Prof. Dr. Eduard Feireisl visited the LBRG On June 14, 2024, the LBRG had the honor to host Prof. Dr. Eduard Feireisl (Czech Academy of Sciences, https://www.math.cas.cz/index.php/members/researcher/37) for a short research visit. He gave a talk on dynamic homogenization of incompressible fluid flows (see https://arxiv.org/html/2404.06782v1) and worked together with Dr. Stephan Simonis, Adrian Kummerländer, Julius Jeßberger and PD Dr. Mathias J. Krause towards the numerical analysis of homogenized lattice Boltzmann methods (see https://arxiv.org/abs/2310.14746) for fluid structure interaction problems.
2024/06/11 - LBRG at ECCOMAS 2024 Last week LBRG attended the ECCOMAS Congress in Lisbon from 3rd to 7th June! Several members of LBRG presented their work. ▶ The techniques developed by the LBRG team are currently used for large eddy simulations of fluid-structure interaction with parallel solution of multiple coupled partial differential equations, and will soon contribute to providing aerodynamics-optimized geometries and reduced noise for wing elements within FALCON ✈ For more information auf FALCON please visit: https://www.lbrg.kit.edu/page/falcon/
2024/03/08 - LBM Spring School in Heidelberg successfully finished The executive committee is happy to announce the closing of the 7th LBM Spring School with OpenLB Software Lab. We hosted 57 participants from 13 countries this year. Congratulations to Jakob Scheel from the US for winning our poster award. We are already busy with organizing the next spring schools. The 8th spring school is planned to take place in Marseille, France from May 19-23, 2025. We would like to thank all participants for attending the 7th spring school in Heidelberg and acknowledge the support from our funders. On behalf of the spring school executive committee (Kerstin Dick, Shota Ito, Mathias J. Krause and Stephan Simonis)
2024/02/23 - New Android App “paint2sim” Released Paint2sim is a mobile application using a Lattice Boltzmann Method realized by the open-source simulation framework OpenLB. This innovative app allows users to scan hand-drawn domains and visualize 2D fluid flow simulations just-in-time on their mobile devices. Whether you're a student, researcher, or engineer, explore fluid dynamics with an intuitive interface with your fingertips. The app is freely available for download. Download and more information For in-depth technical insights, refer to our latest paper, "Just-in-Time Fluid Flow Simulation on Mobile Devices Using OpenVisFlow and OpenLB" Dennis Teutscher and his team developed the app paint2sim as part of the "teaching4future" project, with funding from the Lattice Boltzmann Research Group at KIT and the Ministry of Science, Research, and Arts of Baden-Württemberg, Germany.
2024/02/20 - LBRG joins kick-off meeting for EU-funded project FALCON The EU-funded project FALCON (Foreseeing the next generation of Aircraft: hybrid approach using Lattice-boltzmann, experiments and modelling to optimize fluid/struCture interactiONs) has started in January 2024 for a duration of 4 years and is coordinated by the Université d'Aix-Marseille, France. The project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101138305. The FALCON partners (from 6 countries: Belgium, Czech Republic, France, Germany, Spain, UK) each bring unique expertise in experimental and numerical approaches in fluid and solid mechanics: Aix-Marseille University, Protisvalor, Centre national de la recherche scientifique, Centrale Méditerranée, Airbus, Karlsruhe Institute of Technology (KIT), CS GROUP, MSC Software, German Aerospace Center (DLR), IT4Innovations National Supercomputing Center, Euronovia. FALCON's goal is to enhance the design capabilities of the European industrial aircraft sector by focusing on fluid–structure interaction (FSI) phenomena to improve the aerodynamic performance of aircraft (unsteady loads). FALCON assembles a unique interdisciplinary environment of fifteen public and private institutions and their affiliated entities (from renowned research institutions to SMEs and aircraft high-tier suppliers and integrators) to cover all the required scientific and know-how expertise. Building upon three industrial test cases and tight links with key European partnerships such as Clean Aviation, FALCON delineates a high-impact/low-risk proposal that will significantly contribute to the digital transformation of the European aircraft supply chain. The Lattice Boltzmann Research Group (LBRG) participated in the official kick-off meeting for FALCON (see LinkedIn). Learn more
2024/02/12 - Successful Doctoral Colloquium of Nicolas Hafen Nicolas Hafen successfully passed his doctoral thesis examination. Congratulations to Nicolas and best wishes from the LBRG Team!
2023/09/29 - OpenLB paper is ranked 5th on the list of top cited articles in Computers & Mathematics with Applications We are proud to share that our paper "OpenLB—Open source lattice Boltzmann code" (https://doi.org/10.1016/j.camwa.2020.04.033) is ranked 5th on the list of "Top cited articles published in the past 3 years" in the journal Computers & Mathematics with Applications (IF 2.9, SJR Q1 in "Modeling and Simulation" and in "Computational Theory and Mathematics"). By the way, out of the first five articles in this list, two are on LBM-based software! In addition, within the list of "The most downloaded articles in the last 90 days" our paper is ranking 6th. Three out of the first six papers in this list use #LBM. Thank you to the community for citing us, to the team, the co-authors, the co-developers, and especially to Mathias J. Krause for leading the development of #OpenLB in the past years. You can download the latest release at https://www.openlb.net. Sources Scopus: https://www.scopus.com/ Elsevier: https://www.sciencedirect.com/journal/computers-and-mathematics-with-applications
2023/06/28 - Successful Doctoral Colloquium of Stephan Simonis Stephan Simonis successfully passed his doctoral thesis examination entitled: "Lattice Boltzmann Methods for Partial Differential Equations". Congratulations to the candidate and the reporters PD Dr. Mathias J. Krause, Prof. Dr. Siddhartha Mishra and Assoc. Prof. Dr. Tim Reis!
2023/06/12 - LBM Spring School in Greenwich successfully finished The executive committee is happy to announce the closing of the 6th LBM Spring School with OpenLB Software Lab. We hosted 50 participants from 15 countries this year. Congratulations to Martijn Gobes from the Netherlands for winning our poster award. We are already busy planing next years spring school. The 7th spring school is planned to take place in Heidelberg/Karlsruhe in Germany from March 4th to 8th 2024. n. Thank you all for attending the 6th spring school in Greenwich! On behalf of the spring school executive committee.
2023/01/24 - Teaching4Future Symposium ing4Future Symposium On Tuesday, January 24th, 2023, the research collaboration between the Lattice Boltzmann Research Group at KIT and the CeMOS Research Center (https://www.cemos.hs-mannheim.de) at Hochschule Mannheim presented their results from the "Teaching4Future" research project funded by the Ministry of Science and Art. The aim was to make mathematical and process engineering concepts more understandable for students using XR technologies. Innovative apps such as OpenLBar (LBRG/KIT) and Paint2Sim (LBRG/KIT), as well as ARTIC (CeMOS), were introduced, enabling interaction, simulation, and visualization of 3D data through AR. The apps OpenLBar and soon Paint2Sim can be downloaded for free at https://www.openlb.net. The numerous visitors had the opportunity to extensively test the apps and provide feedback during a relaxed get-together, which also included delicious Weißwürste and Brezeln.
2022/10/25 - Cover Image of Energies, Volume 15, Issue 20 Together with co-authors, members of the LBRG published their work on "Comprehensive Computational Model for Coupled Fluid Flow, Mass Transfer, and Light Supply in Tubular Photobioreactors Equipped with Glass Sponges" in Energies 2022, 15(20), 7671, doi: 10.3390/en15207671. The article was selected as cover story for the current issue. All simulations in the article have been conducted with OpenLB.
2022/07/06 - OpenLBrezel To celebrate the end of our time in home office due to Corona, the LBRG had a get-to-gether on June, the 6th. We enjoyed to meet again in person and got to know each other better while having a giant pretzel and a cup of coffee. The pretzel is now honorary member known as OpenLBrezel.
2022/06/10 - LBM Spring School with OpenLB Software Lab in Kraków successfully finished The executive committee announces the closing of the fifth LBM Spring School with OpenLB Software Lab. We were happy to host 51 participants from 8 countries, including 4 invited speakers in Kraków, Poland. This year’s poster award goes to Pavel Eichler (Czech Technical University in Prague). Next year, the 6th spring school is planned to take place at the University of Greenwich in England/UK from 2023 June 5th to 9th. On behalf of the spring school executive committee, Nicolas Hafen, Mathias J. Krause, Paweł Madejski, Tomasz Kuś, Navaneethan Subramanian, Maciej Bujalski, Karolina Chmiel.
2022/05/14 - LBRG at the KIT campus day The LBRG presents its high performance fluid flow simulations using a desktop computer at the KIT campus day.
2022/04/22 - New paper published in “Fluids” Members of the LBRG published an article about the numerical optimization of pulsation in a micromixer with automatic differentiation. It is available open access at doi.org/10.3390/fluids7050144.
2022/04/12 - New paper published in “Mitteilungen der Deutschen Mathematiker-Vereinigung“ Members of the LBRG published an article about research-oriented teaching under pandemic restrictions (in German: "Forschungsnahe Lehre unter Pandemiebedingungen") in the magazine of the long-standing German Mathematical Society DMV ("Deutsche Mathematiker-Vereinigung").
2022/04/01- Winner of the “Computation 2020 Best Paper Awards” The paper with the title "Evaluation of a Near-Wall-Modeled Large Eddy Lattice Boltzmann Method for the Analysis of Complex Flows Relevant to IC Engines" is one of the two top-voted papers that have won the Computation 2020 Best Paper Awards.
2022/03/11- FILTECH 2022 In March we had the opportunity to present some of our most recent projects at the annual FILTECH fair in Cologne. We discussed with visitors different topics around the lattice Boltzmann method as well as our open source software Open LB and its application. We further presented simulations results with our newly developed AR-App OpenLBar, which helps users to better understand and experience fluid flows through user interactions such as geometry overlay.
2022/01/20 - Latest publication in Journal of Computational Physics For the first time, we used lattice Boltzmann methods (LBM) for temporal large eddy simulation (TLES). Both, LBM and TLES rely on local-in-space computations which upholds high parallelizability. As a proof of concept, we implemented the approach in OpenLB (http://www.openlb.net) and validated it for the Taylor–Green vortex test case which mimics homogeneous isotropic turbulence. The work is a joint effort with the research group of Prof. Dr. Patrick Jenny at the Institute of Fluid Dynamics at ETH Zurich.
2022/01/18 - LBRG member Dr. Mathias J. Krause successfully completes his habilitation The head of LBRG Dr. Mathias J. Krause completed the habilitation examination on January 18, 2022. The thesis is titled Fluid Flow Control and Simulation in Process Engineering Homogenised Lattice Boltzmann Methods. He is now “Privatdozent (PD)” for the subject scientific computing and numerical mathematics for process engineering.
2021/12/13 - SBCB/UFRGS and LBRG meet in Cambara do Sul, Brazil Between December 2 and 9, 2021 members of LBRG/KIT and SBCB/UFRGS met for a workshop in Cambara do Sol, Brazil to conclude their fruitful CAPES/ProBral exchange on Mesoscopic Molecular Dynamics Simulations and discuss future possibilites of collaboration. The participants were able to look back on multiple work and study missions between Brazil and Germany in 2019 and 2021, yielding numerous joint publications. Further highlights included the PhD respectively post doc exchange years of Bruno Iochins Grisci, Pedro Henrique Narloch and Dr. Manuel Riveros Escalona at KIT as well as a two-day workshop on Lattice Boltzmann Methods with OpenLB Software Lab at UFRGS in 2019. A full overview is available on the dedicated project website. The workshop was complemented by excursions to the Itaimbezinho and Fortaleza canyons surrounding Cambara do Sul.
2021/11/24 - LBRG members give talks at the research group 'Schémas de Boltzmann sur réseau' (Institut Henri Poincaré) Mathias J. Krause and Stephan Simonis were invited to give talks at the renowned research group "Schémas de Boltzmann sur réseau" led by François Dubois François Dubois at Institut Henri Poincaré, France. The presented topics include "OpenLB - Fluid Flow Simulation and Control on High Performance Computers" and "Temporal large eddy simulation with lattice Boltzmann methods". Read more
2021/11/19 - Team member Johanna Mödl receives scholarship from the Graduate Funding from the German States For her dissertation project on the subject of simulation of transport processes in lithium ion batteries by use of Lattice Boltzmann methods Johanna Mödl received a scholarship from the Graduate Funding from the German States (Landesgraduiertenförderung), which is awarded to highly qualified young scientists. The project covers modeling and simulation of charge and material transport within a highly resolved battery half-cell. In addition to the transport processes chemical reactions and their simulation through Lattice Boltzmann methods are studied and incorporated in the overall model.
2021/10/11 - (Covid) Virus Risk Simulation Are ventilation systems effective against aerosol emission from breathing? Find out
2021/08/30 - LBRG member Robin Trunk successfully completes his Ph.D. After completing the doctoral examination on July 22, 2021, today, the dissertation titled "Numerical Investigation of the Settling Behavior of Non-Spherical Particles - Application of Homogenized Lattice Boltzmann Methods" has also been published.
2021/05/18 - LBRG member Marie-Luise Maier successfully completes her Ph.D. After completing the doctoral examination on April 30, 2021, today, the dissertation titled "Coupled lattice Boltzmann and discrete element method for reactive particle fluid flows with applications in process engineering" has also been published.
2021/04/22- The LBRG is awarded with the KIT faculty teaching award 2021 for the course “Projektorientiertes Softwarepraktikum“ The KIT faculty teaching award 2021 honors several members of the Lattice Boltzmann Research Group (LBRG) for high quality teaching within the course “Projektorientiertes Softwarepraktikum”, namely Stephan Simonis, Marc Haussmann, Maximilian Gaedtke, Dr. Mathias J. Krause and PD Dr. Gudrun Thäter. Since 2007 the KIT Executive Board grants the faculty teaching award to recognize excellence in teaching throughout the eleven faculties at KIT. The prize is endowed with 10,000 Euros. The prize money is used to enhance the teaching and study experience at KIT. More information and a video portrait of all nominees can be found here.
2020/12/19 - OpenLB Overview Paper Published We are very happy to announce that we have just published our new OpenLB Overview Paper. You can find it on pages 258-288 in volume 81 of Computers & Mathematics with Applications. This paper summarizes the findings of the research that was conducted with OpenLB and gives a brief introduction to the underlying concepts as well as the design of the parallel data structure. It is a great read for newcomers as well as seasoned OpenLB users. The paper can be viewed and downloaded here.
2020/12/02 - LBRG member Maximilian Gaedtke successfully completes his Ph.D. After completing the doctoral examination on November 05, 2020, today, the dissertation titled "Thermal Lattice Boltzmann Methods for the Simulation of Turbulent Flows with Conjugate Heat Transfer – Application to Refrigerated Vehicles" has also been published.
2020/10/13 - LBRG member Marc Haussmann successfully completes his Ph.D. After completing the doctoral examination on September 30, 2020, today, the dissertation titled "Lattice Boltzmann Methods for Turbulent Flows: Application to Coriolis Mass Flowmeter" has also been published.
2020/07/31- OpenLB paves the way to „overnight“ near-wall-modeled large eddy simulations In a collaboration of the Lattice Boltzmann Research Group (LBRG) at the Karlsruhe Institute of Technology (KIT) and the Institute of Reactive Flows and Diagnostics of the department of Mechanical Engineering (RSM) at the Technical University of Darmstadt, the capabilities of two open source near-wall-modeled large eddy simulation (NWM-LES) approaches were investigated to predict complex turbulent flows relevant to internal combustion (IC) engines. Therefore, OpenLB was compared to the commonly applied open source tool OpenFOAM, using a highly precise particle image velocimetry measurement as reference. The comparison covers prediction accuracy, computational costs and ease of use. The performance results show that the OpenLB approach is on average 32 times faster than the OpenFOAM implementation for the tested configurations. The faster calculation speed for NWM-LES using the lattice Boltzmann method implementation in OpenLB is advantageous to address industrial applications and to enable "overnight" calculations that previously took weeks. Checkout our recent publication for more details.
2020/07/06 - How face masks and ventilation of enclosed spaces can protect against infectious aerosols KIT researchers are investigating the formation, detection, distribution and separation of gas-borne particles and droplets as well as the effectiveness of filters. Using simulations, they analyze aerosols, their distribution and deposition in rooms, filters and the human respiratory tract. Read more
2020/05/12 - LBRG student member Marc Siodlaczek wins award for the best simulative bachelor's thesis 2019 The bachelor's thesis with the title "Evaluation of the accuracy of the thermal Lattice Boltzmann method in the transition to turbulent flow", which was supervised by the LBRG, was awarded with the prize for the best simulative Bachelor's thesis by the VM-Verein.
2020/05/01 - New project „Potential for damage to fruits“ funded by BMWi via AiF/FEI starts The research centers TU Berlin (Institute for Food Technology and Food Chemistry, Department of Food Biotechnology and Food Process Engineering) and KIT (Lattice Boltzmann Research Group) cooperate to determine the potential damage to fruits in fruit mixtures during processing. Learn more
2020/04/02 - Project “Virtual Collaboration Laboratories“ funded by the state Within the project, the team headed by Dr. Mathias J. Krause consisting of mathematicians and engineers from the Mannheim University of Applied Sciences (Prof. Dr. M. Rädle) and the Karlsruhe Institute of Technology (Prof. Dr. W. Dörfler, Prof. Dr.-Ing. H. Nirschl) is making existing VR/AR hardware technologies available for teaching to enable a modern education of students in the natural and engineering sciences. It is one of five projects that are supported by the Ministry of Science of the State of Baden-Württemberg with funds from the digital@bw digitization strategy.
2020/03/13 - Spring School 2020 successfully finished The executive committee announces the closing of the third LBM Spring School with OpenLB Software Lab. We were happy to host 60 participants from nine countries, including five invited speakers in Berlin, Germany. This year’s poster award goes to Dominik Wilde et al. from the University of Siegen, Germany. Next year, the 5th spring school (https://www.openlb.net/spring-school-2021/) in planned to take place at the University of Greenwich in England/UK form 2021 May 31st to June 4th. On behalf of the spring school executive committee, Nicolas Hafen, Mathias J. Krause, Harald Kruggel-Emden, Christopher McHardy, Cornelia Rauh, Holger Stark, Robin Trunk
2019/12/11 - Workshop in Porto Alegre/ Brazil Successfully Finished LBM Workshop with OpenLB Software Lab in Brazil Successfully Finished. The executive committee announces the closing of the LBM Workshop with OpenLB Software Lab at UFRGS in Porto Alegre, Brazil. We were happy to host 35 participants including five speakers from LBRG (KIT, Karlsruhe, Germany). The workshop took place in the framework of the Brazilian-German PROBRAL project “Mesoscopic Molecular Dynamics Simulations: Development of Models andComputational Strategies for Complex Structural Bioinformatics Problems” supported by CAPES and DAAD. On behalf of the workshop executive committee, Marcio Dorn, Mathias J. Krause,Stephan Simonis.
2019/11/20 - Pre-Christmas get-together of the LBRG Christmas meeting: The pre-Christmas celebration was attended by graduate workers, Hiwis and PhDs and former employees.
2019/09/17 - The international workshop “Data-driven Modeling and Optimization in Fluid Mechanics“ successfully finished. It focused on the application of artificial intelligence, machine learning, deep learning, evolutional algorithms and adjoint-based optimization to fluid dynamics-related problems with special focus on turbulent flows and flow control. The executive committee were happy to host 95 participants from 11 countries and 3 continents, including 11 speakers in Karlsruhe, Germany. The workshop was organized under the patronage of the “MathSEE“ Centre of the Karlsruhe Institute of Technology and sponsored by - KIT-center MathSEE - DFG Priority Program 1881 - DFG Collaborative Research Center/Transregio 150 The organization of workshop was supported by Institute of Fluid Mechanics and Lattice Boltzmann Research Group at KIT.
2019/04/11 - OpenLB at PowTech 2019, Nürnberg Germany (April 9th to 11th) Our Virtual Reality (VR) approach for process engineering applications shows OpenLB’s latest simulation results. In the VR presentation, an observer can explore the data in a room filling virtual reality with VR glasses and controller. Read more about our VR visualization approach at https://www.openlb.net/vrar-visualization. Learn more
2017/06/07 - OpenLB Community YouTube Channel Update A new video shows the results of a famous benchmark problem in CFD. The lid driven cavity problem illustrates a flow in a cuboid. The top wall moves from left to right with a constant velocity, while the other walls are fixed. The fundamental feature of this often studied fluid flow problem is the formation of a large primary vortex in the center and two smaller vortices near the two lower edges. Different techniques are applied to visualize the fluid flow including the vortices with the cavity. The source code of this simulations can be found in the examples section of the latest release of OpenLB. You will find more information in our show case section. If you have a nice video which you have obtained with OpenLB, please let us know and we will link it or upload it. Please contact us. Warch video
Open Position: Research Assistant (Doctoral Student) in Optimization and Scientific Computing Using Lattice Boltzmann Methods At the Institute of Applied and Numerical Mathematics (IANM) at the Karlsruhe Institute of Technology (KIT) we are looking for a Research Assistant (f/m/d) for our team Lattice Boltzmann Research Group (LBRG, www.lbrg.kit.edu). The position is part of an exciting research project focused on advanced numerical modelling and simulation with focus on sensitivity analysis and optimization for fluid dynamics, solid mechanics, and fluid-structure interaction (FSI) using lattice Boltzmann methods (LBM). After familiarisation, remuneration is paid according to TV-L, E 13. This role provides the opportunity to pursue a doctorate (PhD degree). Learn more
25.08.2025- New Paper published on the consistency of pseudo-potential lattice Boltzmann methods We present a rigorous analysis of the pseudo-potential lattice Boltzmann method (P-LBM), showing its convergence to a PDE under diffusive scaling. By linking model parameters directly to physical properties, we enable simulations with inputs in SI units—no empirical tuning required. The method is implemented in OpenLB and validated with R134a benchmark tests. Further information can be found here
Showcase: Magnetic Separation We are pleased to present a simulation of the deposition of magnetic particles using OpenLB, an open-source lattice Boltzmann method (LBM) software. High-gradient magnetic fishing (HGMF) is a downstream processing technique for biomolecules such as proteins. In the initial step, magnetic particles are coated with a layer containing specific ligands that bind to a designated target molecule. These particles are then introduced into a medium that contains the target molecule, allowing adsorption of the molecules onto the ligands. Subsequently, the particles are separated using a magnetized wire and transferred to another medium. Finally, an elution step is performed to recover the purified molecules. The simulation illustrates the deposition of magnetic particles on a magnetized single wire and models the magnetic separation step of the HGMF process. Dipole forces acting on the particles are taken into account through a coupled discrete element method–lattice Boltzmann method (DEM-LBM) approach, implemented within the open-source software OpenLB.