# Saving data from CfdOF FreeCAD add-on in a usable manner
**URL:** https://discourse.paraview.org/t/saving-data-from-cfdof-freecad-add-on-in-a-usable-manner/17649
**Category:** ParaView Support
**Created:** [July 5, 2026, 6:17pm UTC](https://discourse.paraview.org/t/saving-data-from-cfdof-freecad-add-on-in-a-usable-manner/17649 "2026-07-05T18:17:49Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@mpals](https://discourse.paraview.org/u/mpals)
#### Post date: [July 5, 2026, 6:17pm UTC](https://discourse.paraview.org/t/saving-data-from-cfdof-freecad-add-on-in-a-usable-manner/17649/1 "2026-07-05T18:17:49Z")
Hello,
I’m having an issue with saving data created with the CfdOF add-on in FreeCAD. After my simulation finishes, I can open the data in ParaView just fine. However, I have been unable to save it in such a way that I can open it again to view later.
I tried saving as a .cgns file writing all time steps, but when I open the group of files again, all of my data relating to fluid velocity, pressure, etc. is missing. When I save without writing all time steps, I am locked at time step 0 even though the correct number of total iterations is displayed and I selected the time step I wanted. It also says “max is 0” in the Time Manager “VCR” controls. The 3D model loads, but with no CFD data.
I also tried the Save State option (as a .pvsm file) but it doesn’t work either. It only shows time 0 with no option to select the time step I actually wanted to save. It also only displays 0 iterations. The model will not load (presumably because it’s locked at iteration 0) and the workspace is blank. It does, however, show the pressure data I wanted to preserve when I saved the state.
How can I save my CfdOF data in ParaView so I can open it later to see the 3D model and associated fluid data? Any help with this is _very much_ appreciated. 🙂
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 6, 2026, 4:11pm UTC](https://discourse.paraview.org/t/saving-data-from-cfdof-freecad-add-on-in-a-usable-manner/17649/2 "2026-07-06T16:11:57Z")
> [@mpals](#):
>
> I can open the data in ParaView just fine.
Which format are you using ?
> How can I save my CfdOF data in ParaView so I can open it later to see the 3D model and associated fluid data?
Save into .vtkhdf format.
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### Author:  [@mpals](https://discourse.paraview.org/u/mpals)
#### Post date: [July 7, 2026, 1:00am UTC](https://discourse.paraview.org/t/saving-data-from-cfdof-freecad-add-on-in-a-usable-manner/17649/3 "2026-07-07T01:00:41Z")
When the simulation in CfdOF finished, I just clicked the “ParaView” button in the workbench in FreeCAD, so I’m not sure what the format was.
The .vtkhdf format did the trick though. Thank you for the help.