# pipeCyclic case behaving turbulent when using laminar solver

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July 6, 2020, 08:43
pipeCyclic case behaving turbulent when using laminar solver
#1
New Member

Join Date: May 2020
Posts: 5
Rep Power: 6
Hello,

I set up a case by modifying the pipeCyclic tutorial. I changed the angle of the pipe to 180 degrees and ran the case with simpleFoam. (I made some other changes but this issue has been consistent across all of them) The issue I'm having is that I think it is behaving unexpectedly for a laminar case. As you can see in the image and graph attached (result.png & result2.png), as you approach the centre of the pipe the velocity dips a little before it reaches its max. Is this regular behaviour for laminar flow? Or would this be expected from a more turbulent flow? I thought the velocity would increase as you approached the centre of the pipe due to the friction on the walls of the pipe since this is laminar what other factors would cause this?

This only occurs very close to the top (within 0.0001m). Once you get more than 0.06m down from the top it behaves as I would expect (3.png).

Michael
Attached Images
 result.png (109.0 KB, 11 views) result2.jpg (75.3 KB, 9 views) 3.png (38.9 KB, 8 views)

 July 6, 2020, 16:10 #2 Senior Member   Joachim Herb Join Date: Sep 2010 Posts: 650 Rep Power: 21 It looks like you are plotting the node values. But these are interpolated by paraview from the cell center values stored by OpenFOAM. Do your results change, if you plot the cell center values?

July 7, 2020, 04:08
#3
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Join Date: May 2020
Posts: 5
Rep Power: 6
Quote:
 Originally Posted by jherb It looks like you are plotting the node values. But these are interpolated by paraview from the cell center values stored by OpenFOAM. Do your results change, if you plot the cell center values?
Hi,

Thank you for your quick response. I tried plotting the center cell values by using the point data to cell data filter in paraview. The result is similar to before though, just "blockier" as you can see in the attached image.
Attached Images
 point data to cell data filter.jpg (75.5 KB, 5 views)

 Tags laminar, openfoam, pipecyclic, simplefoam, turbulent