LBRG

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

LBRG

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 .
 

LBRG

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 .