The news about Holzmann CFD in February

Dear fellows, the year starts with a lot of new projects and task while finishing the Ph.D. thesis. I am happy to announce a lot of new things that were already published and the projects that are going to be extended. First of all, the website was further SEO optimized and the newsletter system was improved. I am happy that I got more than 300 subscribers to my mailing list. Please do not hesitate to put you into the list. Second, I feel honored by the people who donated some money to Holzmann CFD. I appreciate that and it shows that the community (you) are giving value to the work I did.

Training Videos

A new project started in the topic of SMART applications that are included within OpenFOAM®. Holzmann CFD started to build the new training series with the setSet application and it will be extended subsequently with other tools such as topoSet, extrude2DMesh and others, which are really helpful for manipulating the mesh or other things. The training lectures are placed in the section »Training - Application«. The lectures will kept short (if it is possible) and are build in order to let you know that these tools exist and how to use them. Furthermore, the purpose of these applications will be discussed.

Training Cases

During the last weeks, Holzmann CFD investigated into different topics such as flow induced rotation by combining the arbitrary mesh interface boundary condition (AMI) with the dynamic mesh library six degree of freedom (6DOF) or a complete buoyancy driven test case. For the latter one you should thank Olivier Dambron, who asked for help in a buoyancy driven case of a very interesting geometrical design. After analyzing the OpenFOAM case, it was so fascinating that a new training case was generated namely the solar chimney. The main topic here is the appropriate applied boundary conditions. There were a lot of new insights into this special topic. Furthermore, the flow induced rotation was re-investigated after some discussion with Tom Fahner. Thanks to both of you.

Co-operation with József Nagy

During the last weeks a new project was discussed with József Nagy in order to provide the community better material and to reduce the work of both (József Nagy and Tobias Holzmann). Right now, there are some ideas which will be discussed during  February. Therefore, the community can look forward to new interesting videos, discussions, training cases and knowledge sharing.

Developments in the OpenFOAM® Foundation Version

The year 2018 starts with a lot of new inventions done by the team around Henry G. Weller. They fixed problems related to the SMALL and LARGE values as well as rewriting the control/solution classes for PISO, SIMPLE and PIMPLE in order to unify things. That means, that the steady-state derivate of some solvers will be removed. The reason for that is the enormous effort to keep both solvers up to date and is related to the complexity and code duplication. One good example is the family of the conjugated heat transfer solvers. Additionally, they made changes to the combustion libraries as well as inventing new functionalities such as wall-boiling or phase change capability based on population balance in coolarboration with HZDR and VTT Finland.

Result of the Community Survey

Dear fellows and CFD enthusiasts, first of all I want to thank everybody who participated to Holzmann CFD's community survey which took place the whole December 2017. The poll got more than 450 votes and demonstrated the interested of the community in Holzmann CFD's work and ongoing projects. Again thanks for participating even though, one knows that there were probably a few people voting more often during the days :o)

The official result of the survey can be checked out » here «

The most interest was the development of a 2D mesh refinement library which will be developed in the next weeks/month. Keep in mind that Tobias Holzmann will finish his Ph.D. the next month and will have a longer holiday after that. The development should come some when during mid of the year 2018.

The second most interest was the investigation into the meshing tool snappyHexMesh and the mesh quality criterion. This topic will be further investigated with new screencasts if there will be time in 2018 to do it.

The community decided to go into this two directions. However, a brief summary of the rest options is given now:

  • Developing in OpenFOAM®
    » There are already a complete series of training videos out - please check out the Training section
  • Combustion Modeling
    » This topic is way to big to describe. In addition Holzmann CFD is only familiar with the flamelet model.
  • Advanced concepts
    » Turbulence related topics can be found elsewhere as well as multiphase and acoustic. The Foundation version does not support the acoustic solvers that's why I never used them or spend time into the solver and its theory.
  • Overset Mesh
    » Same same but different. This library is not supported in the Foundation version and therefore I never checked it out.
  • Holzmann CFD's book - Mathematics, Numerics, Derivations and OpenFOAM®
    » It will be updated after the Ph.D. is done and maybe a new  contributor will participate in the extension of turbulent flow fields.
  • CHT
    » There are already CHT cases published on the website, just search them and get familiar.
  • Characterization of the solvers
    » One will get all the information out of the User Guide.
  • Meshing for irregular terrains
    » Please send me some geometry file in order to prepare one meshing training case. Adaptive mesh refinement is another topic and will not be covered here. 2D meshing is already given in a few tutorials.
  • Turbomachinery
    » That is not my topic at all and the keys not special enough.
  • The rest answers had less or equal 10 votes and are not discussed further.

Thanks for taking part in the poll and thanks for being part of the community.
All the best and keep foaming,
Tobias Holzmann

Suzanne Training

The new training videos are now available and published. Everyone who want to get more familiar with Blender® is warmly welcomed to check out the training session #7. Furthermore, it is demonstrated how the OpenFOAM® meshing, case set-up and solving procedure is done. The submitted PDF and the OpenFOAM® case will be published soon too. Based on the time limitation, the expected result were not achieved and the training case is a bit different to the training video explanation. E.g. the training case were performed by using a steady-state solver instead of the transient one mentioned in the videos. Enjoy.

Community Christmas Competitition

I am happy to announce the availability of the new Suzanne's OpenFOAM® training case and the complementary summary document. You will find the case in the OpenFOAM section with all information you need. The case was generated for the Community Christmas Competition 2017 invented by Jozséf Nagy from Linz. Holzmann CFD is pleased to be part of the community and hope that you enjoy the training case as well as the training videos. Enjoy.

Community Competition

In this area one will find the community contributions that were invented by voluntary OpenFOAM® users such as József Nagy. The videos will give one all necessary information in order to understand and rebuild the cases. It is a place to find all competitions once made for OpenFOAM®. If one is interested to invent an own competition, please do not hesitate to tell József Nagy or Tobias Holzmann about it. We can help you to spread the information in order to make the competition successful. Enjoy.


Christmas Competition 2017 by József Nagy

Holzmann CFD: PDF  |   Training Video