CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Post-Processing (http://www.cfd-online.com/Forums/openfoam-post-processing/)
-   -   How to Plot Eddies in Paraview :) (http://www.cfd-online.com/Forums/openfoam-post-processing/119144-how-plot-eddies-paraview.html)

Alhasan June 10, 2013 18:00

How to Plot Eddies in Paraview :)
 
1 Attachment(s)
Hey All,

i am Trying to get eddies for LES case on my paraview in openFOAM

- i switched the contours on !! no help and i dunno where to go what to do get the eddies :D like the ones i have attached in the image

Please help

Thanks for your time :)

Hasan K.J

zhernadi June 11, 2013 09:12

vortex detection criteria
 
Dear Hasan,

It depends on the vortex detection criteria. You may try using Q utility to generate second invariant of the velocity gradient tensor and visualize a contour of this field. Other option is using Lambda2 utility. But there are other vortex detection criteria as well. I hope this helps.

Zoltan

Alhasan June 12, 2013 22:33

Where is Q utility and Lambda 2 utility
 
Hey Zoltan,

I am not able to find these two utilities the Q utility and Lambda 2 utility ?

- please can u tell where the option is in paraview ?
- i searched i am not able to locate it

Thanks :)

Regards,
Hasan K.J

immortality June 13, 2013 02:19

hi
Execute the commands in terminal.

zhernadi June 13, 2013 03:25

In addition to Ehsan's help, you might be interested in this list of OpenFOAM utilities:
http://openfoam.org/docs/user/standard-utilities.php

immortality June 13, 2013 17:41

1 Attachment(s)
Hi hasan
could you see the vortices?could you attach them?
I used lambda2 and Q without sucess.not any vortices are displayed!

Alhasan June 13, 2013 17:49

No... i havent tried it yet ? but does it actually make a difference if its LES or RAS case...?

immortality June 13, 2013 18:02

i don't think it has a lot of effect on vortices.
what your opinion dear Zoltan?how could I set a contour for labda or Q?is the wide range normal in your opinion?

Alhasan June 13, 2013 21:04

Lambda2 error
 
Hey guys,
My life is never simple and i will never get used to it :mad:

- i typed Q and it worked fine with my case :)
- then i typed Lambda2 and i get this error does any body know what this error means and whats causing it :)

- and Ehsan if you manage to get the eddies please let me know :)

Regards,
Hasan K.J.

and it works only for last time with some warning

Create mesh for time = 10000

Time = 10000
Reading U
--> FOAM Warning :
From function eigenValues(const tensor&)
in file primitives/Tensor/tensor/tensor.C at line 174
complex eigenvalues detected for tensor: (1902.57 7.65293e-07 -0.000402738 7.65293e-07 1902.57 3.34481e-05 -0.000402738 3.34481e-05 4.34386e-10)
--> FOAM Warning :
From function eigenValues(const tensor&)
in file primitives/Tensor/tensor/tensor.C at line 174
complex eigenvalues detected for tensor: (1902.57 7.65152e-07 -0.000250995 7.65152e-07 1902.57 2.85284e-05 -0.000250995 2.85284e-05 1.62937e-09)
--> FOAM Warning :
From function eigenValues(const tensor&)
in file primitives/Tensor/tensor/tensor.C at line 174
complex eigenvalues detected for tensor: (1902.57 7.65293e-07 0 7.65293e-07 1902.57 0 0 0 2.587e-09)
Writing -Lambda2

End

Create time

Create mesh for time = 0

Time = 0
Reading U
#0 Foam::error::printStack(Foam::Ostream&) in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/lib/libOpenFOAM.so"
#2 in "/lib64/libc.so.6"
#3 acos in "/lib64/libm.so.6"
#4 Foam::eigenValues(Foam::Tensor<double> const&) in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/lib/libOpenFOAM.so"
#5 Foam::eigenValues(Foam::Field<Foam::Vector<double> >&, Foam::UList<Foam::Tensor<double> > const&) in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/lib/libOpenFOAM.so"
#6
in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/bin/Lambda2"
#7
in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/bin/Lambda2"
#8
in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/bin/Lambda2"
#9
in "/panfs/storage/local/non-commercial/OpenFOAM/OpenFOAM-SGISLES11-2.1.X_X8664_21JUNE12_REPO/OpenFOAM-2.1.x/platforms/linux64Gcc46DPOpt/bin/Lambda2"
#10 __libc_start_main in "/lib64/libc.so.6"
#11
at /usr/src/packages/BUILD/glibc-2.11.3/csu/../sysdeps/x86_64/elf/start.S:116
Floating point exception

Alhasan June 13, 2013 21:42

No Luck
 
1 Attachment(s)
Hey guys,

the maximum i can get to with my only working Q utility is this much
i tried contours with the Q selected nothing works ?

- if anybody manages to get it or know how to get it please help us :)

thanks

Regards,
Hasan K.J

immortality June 14, 2013 03:42

1 Attachment(s)
how should set contour settings for a good figure?
its a test case.
whats the stages to see vortices contours?
thanks.

wyldckat June 16, 2013 13:22

2 Attachment(s)
Greetings to all!

OK, using Ehsan's test case, here's what's going on: you are being blind-sighted by the maximum values. You need to change the scales down to lower values, such as [-200000, 200000], as shown in the 1st attached image.

If you don't know how to change the scale, read this post: http://www.cfd-online.com/Forums/ope...tml#post429974 - post #2.

As for contours, from the menu, choose "Filters -> Alphabetical -> Contour". Then configure as shown in the second image.

Best regards,
Bruno

youjingxuanlin December 2, 2013 20:37

hi, Alhasan
Have you solved the error with Lambda2? if so, please tell me how to solve it? thanks

Alhasan December 3, 2013 10:16

Quote:

Originally Posted by youjingxuanlin (Post 464495)
hi, Alhasan
Have you solved the error with Lambda2? if so, please tell me how to solve it? thanks

Hi Youjing,

The problem i had was sorted when i put the right value for the Q criterion that i was trying to get on paraView

- First you use the Command and get the Q or Lambda2 from openFOAM

- then you paraView and select the contour botton and apply
- then select the Lambda2 within the Contour dialogue box
- then choose the right range or value, - if you dunno the right range play with the values till you get what you are looking for

All the Best,
Hasan K.J

youjingxuanlin December 5, 2013 20:47

Quote:

Originally Posted by Alhasan (Post 464598)
Hi Youjing,

The problem i had was sorted when i put the right value for the Q criterion that i was trying to get on paraView

- First you use the Command and get the Q or Lambda2 from openFOAM

- then you paraView and select the contour botton and apply
- then select the Lambda2 within the Contour dialogue box
- then choose the right range or value, - if you dunno the right range play with the values till you get what you are looking for

All the Best,
Hasan K.J

Thanks for your fast reply, i think i can solve it now!:D:D


All times are GMT -4. The time now is 18:11.