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Wall with fixed heatFlux boundary condition

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Old   November 17, 2008, 10:49
Default Imposing a heat flux on a surf
  #21
ep4
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Pattyn Eric
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Imposing a heat flux on a surface is equivalent to impose the normal temperature gradient. (q=dT/dn)

Example:

wall{
type fixedGradient;
gradient 2;
}
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Old   November 17, 2008, 15:06
Default Hi, there is a bc on the wi
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Fabian Braennstroem
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Hi,

there is a bc on the wiki:

http://www.cfd-online.com/OpenFOAM_D...ges/1/815.html

Fabian
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Old   November 18, 2008, 03:34
Default Hello Eric, -> FOAM Warning :
  #23
emilianyassenov
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Hello Eric,
-> FOAM Warning :
From function Field<type>::Field(const word& keyword, const dictionary& dict, const label s)
in file /home/rkahraman/OpenFOAM/OpenFOAM-1.5/src/OpenFOAM/lnInclude/Field.C at line 252
Reading "/home/rkahraman/OpenFOAM/rkahraman-1.5/run/tutorials/my_icoFoam/tube_1/0/T::fix edWalls" from line 25 to line 26
expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0.


keyword outlet is undefined in dictionary "/home/rkahraman/OpenFOAM/rkahraman-1.5/run/tutorials/my_icoFoam/tube_1/0/T::bou ndaryField"

file: /home/rkahraman/OpenFOAM/rkahraman-1.5/run/tutorials/my_icoFoam/tube_1/0/T::boun daryField from line 25 to line 39.

From function dictionary::subDict(const word& keyword) const
in file db/dictionary/dictionary.C at line 271.

FOAM exiting
I have put the BC like your example but it gives me that message...
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Old   November 18, 2008, 03:47
Default hi to all someone could hel
  #24
emilianyassenov
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hi to all

someone could help me to how to use that fixedGradient BC?

Best regards

Emo
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Old   November 19, 2008, 07:08
Default Emo: Read the error message. Y
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Ville Tossavainen
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Emo: Read the error message. You need to add word "uniform" after "gradient" and before the uniform value.
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Old   December 5, 2008, 13:08
Default Hi All, I am new to Openfoa
  #26
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Vishal Nandigana
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Hi All,

I am new to Openfoam. I have a case where I need to set B.cs given by the equation

-D1*dC1/dn - K1*C1*dPhi/dn = 0 where n is the normal direction.

I am solving a 2d system hence I want to set the flux in the y direction as zero. i.e
-D1*dC1/dy - K1*C1*dPhi/dy = 0
where C1 and Phi are my variables. I am solving coupled equations.

I hope i will get some response.

Can anyone suggest how exactly I have to go about incorporating this boundary condition.

Kindly do the needful.

Thanks

Regards

Vishal
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Old   February 25, 2010, 03:38
Default fixed wall heat flux BC
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Hi,

are there any news or hints how to impose a boundary condition of fixed heat flux to walls in OF 1.6?

Thanks!!!!!!!
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Old   March 5, 2010, 19:33
Default Fast and Dirty Boundary Condition
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Vitor Geraldes
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One simple way to implement a mixed/Robin boundary condition consists in adding a source term to the scalar transport equation that is zero everywere, except in the control volumes adjacent do the selected patch. This is not a clean approach, but it works quite well.
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Old   March 21, 2011, 03:11
Default
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NieYongguang
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Quote:
Originally Posted by vitor.geraldes@ist.utl.pt View Post
One simple way to implement a mixed/Robin boundary condition consists in adding a source term to the scalar transport equation that is zero everywere, except in the control volumes adjacent do the selected patch. This is not a clean approach, but it works quite well.
Maybe this is a good idea. But if this is multiphase flow in pipe. How do I add the source to energy equation?
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Old   March 21, 2011, 07:22
Default groovyBC.
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Vitor Geraldes
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The best way to deal with this problem is to use the boundary-condition groovyBC. I have tried it in this type of BC and it works quite well. ( please see http://openfoamwiki.net/index.php/Contrib_groovyBC)
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Old   April 12, 2013, 16:55
Default
  #31
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George Pichurov
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Quote:
Originally Posted by vitor.geraldes@ist.utl.pt View Post
One simple way to implement a mixed/Robin boundary condition consists in adding a source term to the scalar transport equation that is zero everywere, except in the control volumes adjacent do the selected patch. This is not a clean approach, but it works quite well.
How do I identify the control volumes adjacent to a given patch in order to assign source term to them?
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Old   December 31, 2013, 05:35
Default
  #32
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Peter
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try something like this:
Quote:
wall
{
type fixedGradient;
gradient uniform 10;
}
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