Combustion Chamber

pimpleFoam, mixing gas streams, objectFunctions, passive scalar


Tobias worked once for the Robert Bosch AG in Lollar, which belongs in former times to Buderus. There, they developed the new generation of bio-mass combustion chambers for private applications. As always, polluted air is a problem in many countries, especially in big cities or at landscapes in which the air exchange is small related to the geographical location. Thus, governments make laws such as TA-Luft, BImSchV in Germany, or stringent global regulation (world bank). Reducing the pollution of, e.g., large engines or biomass combustion chambers using numerical methods can help to reach the climate goals and support and save the environment a bit.

Numerical simulations can be used to optimize the design and thus reduce pollutants, make the design more efficient and effective

The training case shows a unique combustion chamber that allows one to mix the air and fuel stream effectively. After the combustion chamber, a diffusor is added, which leads to a vortex break-down and re-burns the unburned gas. The break-down phenomenon is not taken into account in the scenario prepared here. Mostly, the meshing and set-up of a passive scalar equation is the focus of the case. Thus, the combustion chamber published here is an idea of a new design development done during the Master thesis of Tobias. In 2014, the Robert Bosch AG was investigating in such kind of biomass combustion chambers. The case will mesh a complex geometry using snappyHexMesh and adding layers to the spherical part as well as to the diffusor section. The simulation is arbitrary without combustion (cold-flow). However, function objects are used to generate the passive scalar transport equation on the fly, which could be related to the oxidizer and fuel stream.

Image: Combustion chamber analysis; number 1
Image: Combustion chamber analysis; number 2

Published under the GNU General Public License 3

Over the last ten years, Tobias tried to publish a wide range of different materials related to OpenFOAM® and CFD. You know it much better than he does if the content is worth to be supported. If you want to thank Tobias for the work he did, feel free to tell the community your opinion about the work Tobias Holzmann is doing or you can email your thoughts directly to »«. Keep in mind that the work that was done here took much time, and it is not self-evident that Tobias Holzmann shares all his work, knowledge, and attitude for free and keep the data up to date. Hosting the material, updating the data, and keeping up interesting work for the community does take much time and also money. Supporting Tobias is greatly welcomed and can be done easily by donating any amount you would like to give to support his projects shared on his website.

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The available OpenFOAM® training cases are tested and built for different OpenFOAM® versions (not distributions) on a Linux machine. During the tests, only the OpenFOAM Foundation version of OpenFOAM® was used. Furthermore, the following software packages are required for most of the training cases: Salome®, ParaView®, and for optimization tasks, one also needs the open-source software DAKOTA®. The OpenFOAM® cases might work with the ESI version of OpenFOAM® but it is not supported. For the OpenFOAM® extend project, the training cases will probably not work as the code diverged too much. Additionally, there is no support for Windows-based and MAC-based OpenFOAM® versions.


This offering is not approved or endorsed by OpenCFD Limited, producer and distributor of the OpenFOAM software via, and owner of the OPENFOAM® and OpenCFD® trade marks

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Released on 04.01.2021 — Downloads:
Released on 04.01.2021 — Downloads:
Released on 04.01.2021 — Downloads:
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