[snappyHexMesh] Flux in concencentric tubes

mike6427 · September 19, 2016, 11:33

Hi all,
I'm very new to openFoam. I'm trying to simulate flux inside a system of tubes, of different radius and with some of them surrounding others.
I draw my objects in FreeCAD and then I produce a fluid domain using snappyHexMesh and discretizer. Now I realize that my geometry does not have an inlet or outlet, nor appropriate boundary names.
In order to simulate flux inside tubes I need to define as inlet the void inside the first tube.

Do I need to draw a fake face on the head of the tube? How could refer to that surface otherwise? The same question is valid for the outlet too.
Thank you in advance

Bloerb · September 20, 2016, 10:34

You could already define this in snappyHexMesh. By adding stl files for inlet and outlet in addition to the existing one. Check the tutorials for that.
The other option is to use createPatch and topoSet. You need to create a faceZone. topoSet has tons of options to do that. Those range from an stl file, a disc, box etc. Check in paraview if that faceZone is correct and if it is create a Patch with the createPatch tool. Here you need to choose the patch name and your faceZone.

mike6427 · September 27, 2016, 11:55

Thank you Bloerb and sorry for my late reply. I tried your first solution and it partially worked. I made two bidimensional disks for inlet and outlet in the stl model and created the mesh again with discretizer, but in paraFoam I actually see only the outlet and main body patches, but not the inlet, where I have two concentric pipes. I'll try to simulate this geometry.
Any clue or comment will be greatly appreciate.

September 19, 2016, 11:33	Flux in concencentric tubes	#1
mike6427 New Member Join Date: May 2016 Posts: 5 Rep Power: 10	Hi all, I'm very new to openFoam. I'm trying to simulate flux inside a system of tubes, of different radius and with some of them surrounding others. I draw my objects in FreeCAD and then I produce a fluid domain using snappyHexMesh and discretizer. Now I realize that my geometry does not have an inlet or outlet, nor appropriate boundary names. In order to simulate flux inside tubes I need to define as inlet the void inside the first tube. Do I need to draw a fake face on the head of the tube? How could refer to that surface otherwise? The same question is valid for the outlet too. Thank you in advance Last edited by mike6427; September 19, 2016 at 19:53.

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September 20, 2016, 10:34		#2
Bloerb Senior Member Join Date: Sep 2013 Posts: 353 Rep Power: 21	You could already define this in snappyHexMesh. By adding stl files for inlet and outlet in addition to the existing one. Check the tutorials for that. The other option is to use createPatch and topoSet. You need to create a faceZone. topoSet has tons of options to do that. Those range from an stl file, a disc, box etc. Check in paraview if that faceZone is correct and if it is create a Patch with the createPatch tool. Here you need to choose the patch name and your faceZone.

September 27, 2016, 11:55		#3
mike6427 New Member Join Date: May 2016 Posts: 5 Rep Power: 10	Thank you Bloerb and sorry for my late reply. I tried your first solution and it partially worked. I made two bidimensional disks for inlet and outlet in the stl model and created the mesh again with discretizer, but in paraFoam I actually see only the outlet and main body patches, but not the inlet, where I have two concentric pipes. I'll try to simulate this geometry. Any clue or comment will be greatly appreciate.