WindowsError during SnappyHexMesh

Hi mostaphaRoudsari, thanks for your help, I successfully installed the latest Butterfly, but I meet a problem when I run the indoor airflow 2d file

Do you know how to solve this problem?
PS: the indoor airflow file and outdoor airflow file can successfully operate on my computer

@hc2011301539 Are you running rhino grasshopper in administrator mode?

yep, in administrator mode

WindowsError most of the time happens when you can’t delete a file because it is in still in use. Can you share the full error report? Also trying to run the study in a new folder should solve this problem.

hi @hc2011301539

Try to turn on the snap to true in the snappyHexMeshdict component.

Let us know


I got the same issue. The error file is Also I tried snap to True in snappyHexMeshDict, but no luck.


hi @hc2011301539

I think its a meshing issue and you’ll need more cells in your domain.

You could do so by reducing the cellsize or increasing by 1 or 2 the refinement level of your geometry.

Have a go and let us know

Hi Olivier,

Thanks for helping but it seems not about meshing. It is the snappyHexMesh component. The error message I got is:

Updating global refinement level to (3, 3).
saving the new snappyHexMeshDict.
Runtime error (Win32Exception): WindowsError
line 444, in is_polyMesh_snappyHexMesh, “C:\Users\test\AppData\Roaming\McNeel\Rhinoceros\5.0\scripts\butterfly\”
line 117, in script

Seems that is snappyHexMeshDict cannot be access.



could you share your definition?

Thanks for your reply, but it’s still not working (428.9 KB)

Hi mostaphaRoudsari, I meet a new problem in indoor ventilation analysis, I want to test the ventilation effect of my ventilation blocks, but the results are weird, even after I delete these extra ventilation blocks, the result is still wrong.

wind (827.4 KB) This is the GH file
by the way, sometimes when I run the CFD simulation in butterfly, the values of wind velocity and pressure will appear some very large numbers

For new questions you should open a new topic! You can reference this post in your question if that will be helpful. Thanks.

Sure. Here it is. (425.8 KB)

However, there is no changes at all from the example file.


Just an update of this case. Olivier help to solve the issue but responded on another post.

It seems that the mesh is the main issue. For this case, the _cell_count in BlockMesh was set as {0.2, 0.2, 0.2} in the example file, which is the main cause of the error. After changing it to {70, 1, 60}, the case runs well.

Thanks for helping Olivier.


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Hi Mostapha ! I have an error on the precious component : BlockMesh . Do you know how to solve this. I need it for my work and I’m the only architect there, you’re the onlyone that can help me :slight_smile:

This is the error message: ( I’m french so the first sentence is in french sorry)

  1. Solution exception:Le chemin d’accŠs sp‚cifi‚ est introuvable.

cannot find file “C:/Program Files/blueCFD-Core-2017/system/controlDict”

From function virtual Foam::autoPtr<Foam::ISstream> Foam::fileOperations::uncollatedFileOperation::readStream(Foam::regIOobject&, const Foam::fileName&, const Foam::word&, bool) const
in file global/fileOperations/uncollatedFileOperation/uncollatedFileOperation.C at line 522.

FOAM exiting

tee: ‘log\blockMesh.log’: No such file or directory

hi mostapha i have a problem with snappyhexmesh . can you help me plz???! this error is 1. Solution exception:‘surfaceFeatureExtract’ is not recognized as an internal or external command,
operable program or batch file.

Hi, @mah and @mostapha I too seem to have the same error while running the butterfly indoor airflow sample files. Please let me know if there is a way around it.

Are you using blueCFD-Core 2020-1? If so, I recommend you to use blueCFD-Core 2017-2. butterfly does not support blueCFD-Core 2020-1 yet.
The surfaceFeatureExtract command has been replaced by the surfaceFeatures command in blueCFD-Core 2020-1.

Yes, that was the problem. I installed blueCFD-Core 2017-2, and reinstalled butterfly. Now the sample indoor flow file works perfectly. Thank You!