How to set up a windtunnel in an OpenFOAM solver
I would like to test the aerodynamics of this car project. Its my design. :) It can be downloaded from
You need to login and register there in order to download the model. There is now also EnGrid file format and it should open correctly in EnGrid. Also an old .blend file is included.
I am a total newbie to CFD. I also do not have a formal education for CFD. I have a designer background.
I have understood that I need to setup the model inside a box in 1:1 scale. Furthermore the wind tunnel box has front as an inlet and back as an outlet. The other parts - also the car - are walls in most preprosessors like enGRID. But that's all what I know. In other words I do not know a lot.
Please help me with this project. I would like to make a video about streamlines and also get a valid CD figure for the car. All help appreciated. A good tutorial link might be good.
1. What kind of preprosessor is best for this kind of project?
2. How do I calculate CD value in OF?
3. How do I set up streamline analysis for this kind of model in OF?
4. What books/tutorials/links do you recommend to me which enlighten how to do this kind of test?
I am using CAELinux 2011. I like the release although GEEKOCFD might be more updated. I hope you can advice in many ways. Thanks in advance.
I decided to use Discretizer for my car analyze. I have been following this tutorial and trying to conclude how to apply these settings to car analyze.
However when I press the run snappyHexmesh button the analyze locks ups as follows:
As soon as you have a good *stl of your model, I'll recomend you to follow the Motorbike tutorial in OpenFOAM.
You should be able simulate your model quite straightforward just by pasting your stl model in the folder Trisurface. Some adjustments will be needed, but not that complicated.
As you might start to change your files you can end up making mistakes...for safety reasons make a copy of the original tutorial folder and work on that one.
there is some training material
Generic external aerodynamic simulation training; T. Grahs
Thank you for help! :)
Many thanks for help, I have progressed and I have been able to do at least some kind of wind tunnel analyze. Please look the images included.
However I would like to see much more streamlines in the paraview. So please let me know how add the amount and accuracy of the streamlines. Furthermore I would like to know where I find the Cd value of this tested car of my design in paraview if that is possible. Also lift value is a curiosity.
In general I would also like to see the coloured car where I can see the pressure points of the airflow. I hope you understand what I mean. I also would like to animate the streamlines in Blender and create such an image where streamlines are like real smoke in a wind tunnel.
Also if you have some ideas how to improve the realism and accuracy of the analyze please tell. All critics is most welcome without that I cant improve in the art of aerodynamics.
Which adjustments does I need?
i'm working with openFoam since a few weeks and made a few tutorials. Now i'd like to include my own geometry as a .stl file. I copied my "geo.stl" file into triSurface, changed the file name in snappyHexMeshDict from motorBike.obj to geo.stl and made a comment # in the .Allrun file in front of
"cp $FOAM_TUTORIALS/resources/geometry/motorBike.obj.gz constant/triSurface/"
What else does i need to change to make it work?
Because at the moment, if i try to run ./Allrun or just blockMesh it ignores my .stl-file. Maybe i'm completely on the wrong way, because i'm still beginner and don't understand all steps.
btw: os: Ubuntu 13.10, openFoam 2.3.0
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