CFD Online Discussion Forums

CFD Online Discussion Forums (
-   OpenFOAM Post-Processing (
-   -   Free surface - interFoam (

Pallav June 7, 2011 00:30

Free surface - interFoam
1 Attachment(s)

I am trying to follow the free surface tutorial by Hassan Hemida which can be found at

I am not able to get the right outputs which should be like the attachment that I have uploaded.

I have tried creating contours for the same but I do not get similar outputs as shown in the tutorial.

In the tutorial it is mentioned that these outputs are taken at a particular time step. How can this be done using paraFoam?

Please advise.

Thank you.


flowris June 10, 2011 01:35

All tutorials on multiphase can be found in OpenFOAM/OpenFOAM-1.7.x/tutorials/multiphase.

gwierink June 10, 2011 09:02

Hi Pallav,

The pic you uploaded is taken at 0.4 s, at least that is what the tutorial says. The field you see is gamma, the phase fraction field. In the latest version of OpenFOAM this field is called alpha. In paraFoam, select field "alpha1" and go to timestep 0.4 s with the forward button.


Originally Posted by flowris (Post 311382)
All tutorials on multiphase can be found in OpenFOAM/OpenFOAM-1.7.x/tutorials/multiphase.

No, not this one.

Pallav June 12, 2011 02:19

2 Attachment(s)
Thanks Gijsbert and Joris for your replies.

I am running OF-1.7-x and made modifications to the dambreak tutorial as per the instructions mentioned in the pdf.

I did not get any output for gamma as shown in the pdf. When I choose 'Set color by' to gamma, I get output as the attachment, 'choose gamma in display tab'. This looks as it should. However, when I hit the play button I get the output as the second attachment, 'hit play button', for all time steps.

So, I tried to download and run the actual case file posted at
However, I ran into a lot of errors (eg: could not find cAlpha in PISO)

I still refer to pdf files as tutorials. Sorry, my bad.
I wanted to know if there are some more pdf files with instructions which will help me learn how to set up cases for studying phase fractions using VOF.

gwierink June 12, 2011 03:43

1 Attachment(s)
Hi Pallav,


Originally Posted by Pallav (Post 311638)
could not find cAlpha in PISO

Have you looked in system/fvSolution, line 59 (if the file is still original)?
If you're looking for something and really cannot find it, it may be handy to use e.g.:

[gijsbert@orava fillingBottle]$ grep -irn calpha .
./system/fvSolution:59:    cAlpha          1;

where option "i" means ignore case, "r" means recursive, and "n" means display line number.

When following the tutorial "1.7.x style", I do get output, although slightly different. But I must say that I did not go through every detailed setting. Just running the case with laminar interFoam I get the pic attached. Let me know if you need the case file.

Pallav June 13, 2011 02:13

Thank you Gijs.

I managed to run the case and obtain similar outputs. I had to make some more changes to the damBreak tutorial which were not mentioned in the pdf.

However, I would like to compare your case file with mine for better understanding. So, please send it to me.


gwierink June 14, 2011 00:15

Hi Pallav,

No problem, here is the case I used.

Pallav June 14, 2011 15:17

Thanks a lot, Gijs.

All times are GMT -4. The time now is 23:51.