'Momentum Source' Fan causes FATAL ERROR

Hi! I’m running a ‘Conjugate Heat Transfer V2’ simulation on an electronics enclosure with internal and external fluid domains.
The simulation works fine until I add a Fan type ‘momentum source’ to the model.
Simscale simply says that " an error occurred" and when I open the solver log I get the following error message popping up (amongst others):

[10] → FOAM FATAL ERROR: (openfoam-2112)
[10] fanMomentumSource momentumSource_0_0: Unknown face zone name: region9_boundingFaces. Valid face zones are:
23

It seems the issue is related to the momentum source but i’m not sure how to interpret the error log or what is wrong.
My main source of confusion when setting up the fan is how to define the physical volume of the fan, (ie should it be defined as a solid material, a fluid volume, just left as a void, or none of the above?) I have tried all these options but the simulation always seems to fail. Any help would be greatly appreciated.

Below is a link to the project:

Thanks in advance!

Hello, and thank you for using the Forum. As I could see in your latest simulations, fan zone is left as a void. This is not needed, and will cause issues.
What I’d recommend is to create a complete fluid geometry covering fluid+fan zones, and a seperate cylinder geometry that will represent the fan momentum zone.
Below, there is an example project to simulate internal fans by using momentum source. You can see the fluid domain is created covering the fan zone as well, and a cylinder geometry is created seperately. Air material is assigned to the whole flow region, and fan momentum source is applied to the fan geometry.

Hope this helps.

Thanks for your reply!
I have tried your recommendation, using a cylindrical geometry primitive for the fan zone, without creating a void in the fluid zone. Unfortunately I’m still having the same issue.
Even more odd is the fact that the simulation works fine when I use an ‘average velocity’ momentum source, with everything else being the same.
Perhaps the issue is related to the the way I’m setting up the fan specifically, although the only settings that change are the use of a table to define the pressure vs flow rate of the fan… and I’ve tried using different combinations of values for that as well.
Not really sure what else to try :confused:
Cheers and thanks for your help.

Thank for the information! Can I ask which geometry that you used on the Geometry list for a cylindrical geometry primitive, and without the void? I’ll have a deeper look into issue.

Thanks for all your help.
The attached image shows the item I’ve used for the fan geometry (circled in blue.) Its called “Cylinder 2” and is in the “Geometry Primitives” drop down list.
For the internal fluid zone I’m using the last “Flow region” body in the geometry dropdown list (circled in red.)
Just let me know if you need any more info.
Cheers and thanks.

Hello, thank you for the response. The issue you are currently facing seems like a bug, and we’ll report it to our development team. Thank you for reporting this.
Best.

Alright good to know, thanks.