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HeatFlux in buoyantBoussinesq

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Old   November 16, 2010, 15:41
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Originally Posted by David_010 View Post
Hi ubaid

snGrad is the gradient normal to a surface. The gradient term can be evaluated in different manners, and in the case of the temperature gradient at the wall, the heat flux expression q=k(DT/DX) employs the gradient normal to that wall, so snGrad is the correct way.

I suggest you to take a look to the Programmers Guide, I think it explains this better than me.

Hope it helps, regards

Hallo David,

Thanks a lot, i got what you meant. I will look at manual closely.

Best Regards,
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Old   March 8, 2011, 10:35
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Sarah K÷hler
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Hey Foamers,

i just tried the turbulentHeatFluxTemperature bc in the buoyantBoussinesqPimpleFoam tutorial case with OF-1.7.1.
I exchanged all the kappaEff with alphaEff. Its reading all the files, starts the time loop and breaks up directly. i got a:

request for volScalarField unifrom from objectRegistry region0 failed
available objects ot type volScalarField are

do i need to add a field in createFields?
Thought its ok, when i just add a value in the 0/T file ...

Any suggestions?

Thanks in advance!

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Old   August 17, 2011, 09:20
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Anne Gerdes
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Dear Foamers,
can someone explain me why OF1.7 still uses

HTML Code:
- ghf*fvc::snGrad(rhok)*mesh.magSf()
instead of

HTML Code:
fvc::interpolate(rhok)*(g & mesh.Sf())
as it was used in the previous version OF1.6.
I do not understand why the gradient of the densitiy is used while in the equations I find in literature it has to be just the densitiy multiplied with the constant g.
Can someone help me? Is this still a bug or do I overlook something?
Also in the Wiki-Link
they use the interpolated density instead of the surface normal gradient.
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