
[Sponsors] 
March 21, 2014, 20:10 
velocity U in the Calculator Problem

#1 
Member
ziehjay
Join Date: Jul 2013
Posts: 43
Rep Power: 5 
Hey guys,
i am working with the tool calculator in paraview right now. Unfortunately it does not accept my U as a scalar value, when i want to integrate the velocity U in my calculation. This error occurs: ERROR: In /home/sanjar/OpenFOAM/ThirdParty2.2.x/ParaView3.12.0/VTK/Charts/vtkPlotPoints.cxx, line 641 vtkPlotLine (0xdc0b280): No Y column is set (index 1). Does somebody has an answer or a suggestion how to fix this problem? Background of this problem: Bridge ANSYS and paraview thank you guys and thanks for every helping suggestion!! 

March 24, 2014, 13:49 

#2 
Member
ziehjay
Join Date: Jul 2013
Posts: 43
Rep Power: 5 
hey guys, anybody out there who could say what the problem might be..?
still couldnt figure it out :/ thanks! 

March 25, 2014, 09:26 

#3 
Member
ziehjay
Join Date: Jul 2013
Posts: 43
Rep Power: 5 
hey guys,
i thought it would make sense if i explain and show you the things i did so far to solve my problem. AIM: get the same plots like the ones from ANSYS (see pic 1) 1. typed into calculator the formular p + (0.5*997.561*(UČ))  997.561 is the density of water  U is my veloocity, but it did not work because calculator did not accept the scalar, so i just typed in my starting velocity at the inlet 13 m/s > Result: got a plot like in pic 2,3,4 > Problem: all three plots do not start from 0 respectivey from a negative point like in ANSYS, because i used 13, 9 and 5,4 m/s and not the scalar 2. tried to check if a got velocity on my plate of my geometry, there is no velocity > looking: Bridge ANSYS and paraview changed my BCs from > to Code:
dimensions [0 1 1 0 0 0 0]; internalField uniform (0 5.4 0); boundaryField { WALL { type fixedValue; value uniform (0 0 0); > (0 5.4 0) } OUTLET { type pressureInletOutletVelocity; value uniform (0 0 0); } EROSIONPLATE { type fixedValue; value uniform (0 0 0); > (0 5.4 0) } INLET { type fixedValue; value uniform (0 0 0); > (0 5.4 0) } but i generate such plots if i use calculator and the vector U_Y or even the normal velocity of 5.4 m/s (see pic 5) I really dont know where my problem is? if there is somebody who could help me, please spend some minutes and explain/show it to me..its pretty important! thanks! 

March 25, 2014, 14:38 

#4 
Senior Member
Joachim Herb
Join Date: Sep 2010
Posts: 387
Rep Power: 11 
Do you plot the velocity on a wall? Then it is set by the boundary conditions to be 0. So the result is correct. Are your boundary conditions the same in ANSYS and OpenFOAM? It looks like you might be using free slip conditions in ANSYS and no slip in OpenFOAM for that wall? Can you post your 0/U file of OpenFOAM and (parts of) the ccl file of Ansys (if you use CFX)?


March 25, 2014, 14:47 

#5 
Member
ziehjay
Join Date: Jul 2013
Posts: 43
Rep Power: 5 
hello,
no i plo the velocity on the plate, where the flow is sprinkling on. (i uploaded a pic which i made in paint a long time ago :) ) above your post there is my 0/U file. i dont think that it has something to do with the BCs in OF and in ANSYS because my plot in OF has the same peak (maximum) like the one in ANSYS. the problem for me is the y axis (yachsenschnittstelle) because it does not start with 0 but with a higher value. and this value comes from the formule i use in the calculator, which you can see above. i tried to plot just the normal pressure (relativdruck, also ohne diese formel) and this one was right because it also starts from negative yaxis but i dont reach the peaks. so all in all, it has smething to do with the problem that i cant use my scalar AND vector U in the calculator. Both doesnt work. thank you for your attention. 

March 25, 2014, 17:10 

#6 
Member
ziehjay
Join Date: Jul 2013
Posts: 43
Rep Power: 5 
nevertheless joachim,
i am still looking forward for new suggestions! 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Plotting Radial Velocity and Tangential Velocity in CFD Post  ashtonJ  CFX  5  July 13, 2015 02:49 
Velocity in Porous medium : HELP! HELP! HELP!  Kali Sanjay  Phoenics  0  November 6, 2006 07:10 
Neumann pressure BC and velocity field  Antech  Main CFD Forum  0  April 25, 2006 02:15 
Terrible Mistake In Fluid Dynamics History  Abhi  Main CFD Forum  12  July 8, 2002 09:11 
what the result is negatif pressure at inlet  chong chee nan  FLUENT  0  December 29, 2001 06:13 