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-   -   yPlusRAS (http://www.cfd-online.com/Forums/openfoam/68048-yplusras.html)

vw.cfd September 4, 2009 05:57

yPlusRAS
 
1 Attachment(s)
Hi,

I am simulating a 2 phase cavitating flow problem and would like to check the yplus value of my grid. But, when i execute the standard yPlusRAS option available in OpenFAOM v1.5 i receive an error message:
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time
Create mesh for time = 0
Time = 0
Reading field U
Reading/calculating face flux field phi


keyword transportModel is undefined in dictionary "/usr2/daten/enallap/ansa/ventil.simple.dlay/constant/transportProperties"
file: /usr2/daten/enallap/ansa/ventil.simple.dlay/constant/transportProperties from line 17 to line 65.
From function dictionary::lookupEntry(const word& keyword) const
in file db/dictionary/dictionary.C at line 213.
FOAM exiting

i am attaching my transportPropertiesdict file for reference.

Please help:confused:
ThnX!!!

chbenz September 4, 2009 09:17

hi,

i think yPlusRAS is only valid for singlephase flow. this means that your transportProperties-dict is not appropriate for this app.
maybe you could try to define another dict.

Christof

juliuslein April 1, 2010 06:14

yPlusInterRas
 
Hello together,

I'm not sure if you are still interested but when I had the same problem with 2-phase-flow I modified the yPlusRas tool for OF-1.5. Now it only checks the liquid phase but normally that's the interesting one in your cavitation case.
If you want I can upload it here. But it's no big thing, it just reads the values from another sub-dictionary....

Regards, Julius

Hydro1004 May 4, 2010 08:07

yPlusRAS
 
Hi Julius,

Can you please upload your modified yPlusRAS tool that you created?

Cheers,
Mai-Chi

juliuslein May 4, 2010 10:56

yPlusInterRas
 
1 Attachment(s)
Hello Mai-Chi,

here is the little tool. But please take care since it only uses the first phase mentioned in the transportProperties file.

Hope the tool helps you a bit,

Regards, Julius

Hydro1004 May 23, 2010 01:22

thanks for the post julius, it was really helpful. do you by any chance know how to compute forces in two phase flow?

mai-chi

juliuslein May 25, 2010 09:36

Hi Mai-Chi,

just look into Mark Couwenbergs solver "shipFoam" he presented in the forum some time ago.

http://www.cfd-online.com/Forums/ope...e-gravity.html

there you find the necessary files with the integrations over the surfaces and everything. For example in the first revision of "shipFoam" there is the "hullforces.H" which calculates the forces.
For 2-phase flow no explicit gamma (alpha1) term is necessary because the density is already implemented in the pressure term.

Regards, Julius

paka September 30, 2010 07:18

Good day to everyone,

Could anyone please take a look how to modify the tool for use with OpenFOAM 1.7? I tried to tackle it on my own, but no success. I'm not sure where to go from there.

Any help is highly appreciated.

Have a great day everyone!
K


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