parabolicVelocity as boundary condition in OF-1.7?

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 February 25, 2011, 09:32 parabolicVelocity as boundary condition in OF-1.7? #1 New Member   Join Date: Nov 2010 Posts: 5 Rep Power: 7 Dear All, as to OpenFOAM version 1.5 there was a boundary condition called 'parabolicVelocity' where parabolic velocity-profiles were applied to patches. So my question is: Is there any comparable patch-/boundarycondition that can be used? Or: I got another computation where i can see the parabolic profile in Paraview - how can i export it and use it as inlet-BC for another case? With best regards, CST

 March 1, 2011, 03:21 #2 Member   Alan Russell Join Date: Aug 2009 Location: Boise, Idaho USA Posts: 61 Rep Power: 9 CST, One way to create a parabolic inlet velocity profile is in the tutorials. Look through tutorials/incompressible/simpleFoam/pitzDailyExptInlet. The profile is in the constant/boundaryData/inlet directory. You set up the points file to specify points and the /0/U to set the velocity at each point. I use this method frequently - it's easy to set up. If this doesn't work, you can search the forum for velocity profiles or inlet profiles. Good luck, Alan solefire likes this.

 March 2, 2011, 04:30 #3 Member   Frederic Collonval Join Date: Apr 2009 Location: Technische Universitaet Munich - Lehrstuhl fuer Thermodynamik Posts: 53 Rep Power: 9 CST, Another possibility is to use the groovy boundary conditions see http://openfoamwiki.net/index.php/Contrib_groovyBC Something like this should make the trick in 2D: inlet { type groovyBC; variables "yp=pts().y;minY=min(yp);maxY=max(yp);para=-(maxY-pos().y)*(pos().y-minY)/(0.25*pow(maxY-minY,2))*normal();"; valueExpression "10*para"; value uniform (10 0 0); } Best regards, Frederic solefire likes this. __________________ Frederic Collonval Technische Universität München Thermodynamics Dpt.

March 20, 2012, 12:51
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Goutam Saha
Join Date: Dec 2011
Location: UK
Posts: 131
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Quote:
 Originally Posted by AlanR CST, One way to create a parabolic inlet velocity profile is in the tutorials. Look through tutorials/incompressible/simpleFoam/pitzDailyExptInlet. The profile is in the constant/boundaryData/inlet directory. You set up the points file to specify points and the /0/U to set the velocity at each point. I use this method frequently - it's easy to set up. If this doesn't work, you can search the forum for velocity profiles or inlet profiles. Good luck, Alan
Dear Alan

I have simple pipe flow case, length is 1.2 m and radius is = 0.02595 m.
I want to generate the the points file for my case. U(x) = 2U_0 [ 1 - (x/r)^2 ]
x and y varies from -0.02595 to -0.02595 and z varies from 0 to 1.2. Could you give me some suggessions about points file and velocity file in he constant/boundaryData/inlet directory.

Thanks

 March 22, 2013, 10:51 #5 Senior Member   starter Join Date: Sep 2012 Posts: 109 Rep Power: 8 Alan Do you have any tutorial for fixing points and velocity. I am a beginner in OpenFoam who is trying to do his MS in CFD. Can you give me a few tips as i have to use 1/7th power law for turbulent flow in my pipe. Regards

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