CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

How to modify oodles to print epsilon

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 9, 2008, 13:37
Default Hi Gijs, check that "create
  #1
Member
 
Ville Tossavainen
Join Date: Mar 2009
Posts: 60
Rep Power: 17
villet is on a distinguished road
Hi Gijs,

check that "createMyFields.H" is included after "createFields.H". Also check the equation for dissipation rate. It doesn't look like the right one...

Anyway, I have another solution. You can call "sgsModel->epsilon()" that computes TKE dissipation estimation (ce*ksgs*sqrt(ksgs)/delta for eddy viscosity models).

Hope this helps!
Ville
villet is offline   Reply With Quote

Old   December 9, 2008, 14:30
Default Hi Ville, How are things? T
  #2
Senior Member
 
Gijsbert Wierink
Join Date: Mar 2009
Posts: 383
Rep Power: 18
gwierink is on a distinguished road
Hi Ville,

How are things? Thanks for your reaction. I did put "#include createMyFields.H" after createFields.H. The equation is just a guess, because I also tried:



Info<< "Calculating the dissipation.\n" << endl;
volScalarField dissipation
(
IOobject
(
"dissipation",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
sgsModel->epsilon()
);



and that didn't work. Well, it does write out a file called "dissipation" every timestep, but it only contains the same info as the initial conditions (i.e. zerGradient for most things and some fixed values for the two inlets). Any idea how to fix that?

Thanks, Gijs
__________________
Regards, Gijs
gwierink is offline   Reply With Quote

Old   December 9, 2008, 15:54
Default Uups, you need to update epsil
  #3
Member
 
Ville Tossavainen
Join Date: Mar 2009
Posts: 60
Rep Power: 17
villet is on a distinguished road
Uups, you need to update epsilon somewhere in the code:

dissipation = sgsModel->epsilon();
villet is offline   Reply With Quote

Old   December 10, 2008, 02:36
Default So you mean I should put "diss
  #4
Senior Member
 
Gijsbert Wierink
Join Date: Mar 2009
Posts: 383
Rep Power: 18
gwierink is on a distinguished road
So you mean I should put "dissipation = sgsModel->epsilon();" in myoodles.C and have it also in createMyFields.H ?
__________________
Regards, Gijs
gwierink is offline   Reply With Quote

Old   December 10, 2008, 05:13
Default Hi Ville, Thanks for your h
  #5
Senior Member
 
Gijsbert Wierink
Join Date: Mar 2009
Posts: 383
Rep Power: 18
gwierink is on a distinguished road
Hi Ville,

Thanks for your hint. To recap for others, this is what worked (at least for a few time steps, still need to test it for longer times):

Put in myoodles.C the lines "#include createMyFields.H" and "dissipation = sgsModel->epsilon()". Then, create a file called "createMyFields.H" (or whatever you like of course) with the code:

Info<< "Calculating the dissipation.\n" << endl;
volScalarField dissipation
(
IOobject
(
"dissipation",
runTime.timeName(),
mesh,
IOobject::MUST_READ,
IOobject::AUTO_WRITE
),
mesh
);

Now every writing step a file called "dissipation" is written that contains a field of subgrid epsilon.

Many thanks for your help Ville ( and also many thanks to Ville Vuorinen for helping me out)!

Cheers,

Gijs
__________________
Regards, Gijs
gwierink is offline   Reply With Quote

Old   December 10, 2008, 09:02
Default That's good to hear you got it
  #6
Member
 
Ville Tossavainen
Join Date: Mar 2009
Posts: 60
Rep Power: 17
villet is on a distinguished road
That's good to hear you got it working!
villet is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Modify, G_k,k and epsilon values on wall functions Javier Larrondo FLUENT 0 September 15, 2008 22:34
Print Residual Jan Siemens 0 November 4, 2003 09:19
Print MON FLUENT 3 October 9, 2002 11:13
PRINT VALUE FROM UDF Pravesh Kumar FLUENT 5 October 9, 2002 02:53
Image Print Matthew Campbell CFX 4 October 10, 2001 06:21


All times are GMT -4. The time now is 18:10.