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Mr. Carsten Fuetterer

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Posts posted by Mr. Carsten Fuetterer

  1. Posted · Report reply

    Hi Lu,

     

    to be honest, it seems to be relatively difficult, to change the number of rims with some sort of transformation. Changing the shape of the rims should be easy with our freeform deformation.

     

    So if changing the number of rims is really important, you should think about creating a fully parametric model of the wheel.

     

    best regards

     

    Carsten

  7. Posted · Report reply

    Hi guys,
     
    today I want to share with you my latest feature which creates a bounding box for your OpenFoam internal flow geometry.
     
    The idea came, when I struggled with SnappyHexMesh because the edges of the boundaries where not captured correctly, which resulted in a bad prismlayer mesh like this:

    post-85-0-29484700-1493713401_thumb.png
     (image 1)
    I found out that the reason for this, was the bounding box, where the inlet and outlet boundary do not lay within the first layer of the box like this:

    post-85-0-09248300-1493713501_thumb.png

     (image 2)
    So I created I bounding box which automatically adjusts with the changing geometry. It calculates the maximum and minimum positions and creates the bounding box with a user specified offset. A nice setup looks like this:

    post-85-0-37101400-1493713552_thumb.png
    (image 3)
    This setup produces a nice volume mesh with clean prism layers:

    post-85-0-90882000-1493713501_thumb.png

    (image 4)
    The complete bounding box, where the subdivision in x, y and z coordinates can be specified, looks like this:

    post-85-0-38621000-1493713555_thumb.png

    (image 5)

    The following picture shows how to connect the BlockMeshDict with the bounding box feature:

    post-85-0-55223900-1493713506_thumb.png
     (image 6)

    Remember that you have to create an entry for the vertices by selecting these, right click and select new entry:

    post-85-0-15851000-1493713553_thumb.png

     (image 7)

    This creates a new entry in your config dialog. There you have to change the type to FString:

    post-85-0-76816300-1493713555_thumb.png
     (image 8)
    Do the same for the line where the blocks are defined (see image 6).
    Now you have create a new entry for the point in mesh, which you can find in your SnappyHexMeshDict. Follow the same procedure, but just mark the three coordinate like this for a new entry:
    post-85-0-50560300-1493713553_thumb.png
    (image 9)

    That's it. This is just a first version of the feature. I could imagine to write another feature for the creation of the bounding box for external flows, where you could specify different patches within the BlockMeshDict.

     

    Of course you are also welcome to post your features here in the forum.

     

    Attached is the feature and an example how to use this feature with a complete software connector. This example by the way couples OpenFoam for Windows with CAESES.

     

    Have a nice day

     

    Carsten

    duct_win_forum.fdb

    OpenFoam_BoundingBox.fdf

    post-85-0-43087300-1493713502_thumb.png

    post-85-0-39223500-1493713509_thumb.png

    post-85-0-88454400-1493713553_thumb.png

  9. Posted · Report reply

    Hi,

     

    I want to share with you a feature, which writes all parameter and design variables into a file ("allParameter"). In the arguments you can decide if you want to include parameter or just use the design variables.

    The feature also creates an .fsc ("setParameter.fsc") file. This can be used to create a specific setup from the file. To open the fsc file in gui mode just go to File->Execute Script.

     

    cheers

    writeParameterToFileAndBatchFile.fdf

  10. Posted · Report reply

    Hi,

     

    the usal way of visualizing data from OpenFoam is to create a file like foam.case in the calculation directory and to import this file. The problem is with this method, that only the data of the internal mesh are displayed in CAESES and that you do not have the values of the boundary faces.

     

    To see these values you can export your OpenFoam data to VTK. This is done with follwowing OpenFoam command:

     

    foamToVTK -latestTime

     

    With this command a new folder called VTK is created with the VTK files of all boundaries and patches. Theses different files can be imported into CAESES and values like Wall Yplus or pressure can be displayed.

     

    Have a great start into the week :-)

     

    Carsten

     

    post-85-0-50152600-1439801164_thumb.png

  13. Posted · Report reply

    Hello Henrik,

     

    did you run a sobol or a sensitivity analysis by dakota first? I would do this to scan the design space. Then you could try the Local Optimization Efficient Algorithm by Dakota. This is a local search with a surrogate model (response surface). It can use the results of the DOE to build a first response surface. It will optimize internaly on this and will calculate the best design and so on. I had some good results when I set the samples per iterations to zero. This means it will calculate just one design of the response surface.

     

    But this is just one way to optimize.

     

    Does this gives you a first idea?

     

    cheers

     

    Carsten

  19. Posted · Report reply

    could it be that you use Ubuntu 14.04lts? and that you therefore had to compile OpenFoam for your own? Then you have to write

    of230

    to load the bashrc.

    So try to insert "of230" at the second position of the Allrun script. Mabe you have to adjust the version number.

     

    Maybe you can have a look on your profile ~/.bashrc file

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