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QBlade ForumQBlade: Rotor AerodynamicsQuestion about the velocity expor …

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Question about the velocity export

#1 · 1. March 2025, 03:45

Dear David,

In the simulation setting, I set the output data stored after 400s and I have set the store replay. But I cannot export the velocity field of the Free vortex wake after the 400s, may I know why?

Thanks

Chris

#2 · 1. March 2025, 06:19

And also seems the velocity field exporting on Linux system have problems.

thanks

Chris

#3 · 2. March 2025, 18:38

Hi Chris,

the functionality to export velocity fields should be working correctly. Could you give some additional information regarding the issue you are facing?

What is not working? Are no files generated, is there a crash or is no data generated during the export?

Regarding the export options on Linux: On Linux, the native file dialog is used by default, and unlike its Windows counterpart it doesn’t automatically append the selected file extension, which is preventing the file generation.

To export on Linux you need to explicitly add the file extension: .txt or .vtr

BR,

David

#4 · 3. March 2025, 04:31

Dear David,

Thank you that the adding .vtr works now for Linux. For the first question, I still cannot solve. It does not output any velocity file if I set “Store Output From [s]:400” and I want to export the velocity field file after 400s. I have tried both Windows and Linux system and they cannot work. May I know why?

thanks

Chris

#5 · 3. March 2025, 08:34

Dear David

In addition, I would like to how to export the “turbine.vtu” in Linux system as the Linux system only export the “tower.vtu” file. I tried on Windows and it works to export “turbine.vtu”.

thank you,

Chris

#6 · 3. March 2025, 13:30

Hi Chris,

thank you for reporting this issue. I found that when using the “all_next” option during exporting in combination with the “store output from” feature, the velocity fields are not exported correctly. I have already fixed this for the next upcoming release. A workaround for the time being is to not use the “store output from” feature, when you want to export velocity fields over a range of timesteps.

On another note, I’m not sure what you mean by the “tower.vtu” file. When exporting a cut-plane or velocity field, the expected output includes a “_blade.vtu” file and a “_turbine.vtu” file, along with the velocity distributions.

Are you using the latest release, QBlade 2.0.8.5?

Best,

David

#7 · 3. March 2025, 16:51

Dear David,

For the Linux system, I currently use an older version 2.0.7.7 as I met the error of libQt5Test for the version QBlade 2.0.8.5, and seems the libQt5Test is not in your quick start guide.

thanks

Chris

#8 · 3. March 2025, 18:46

Hi Chris,

you can simply install the missing test library by calling:

sudo apt install qttools5-dev

BR,

David

#9 · 5. March 2025, 09:33

Thank you David, the script works now.

Best regards,

Chris

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