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buoyantBoussinesqPimple p_rgh BOUNDARY CONDITIONS

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Old   May 7, 2014, 04:23
Post buoyantBoussinesqPimple p_rgh BOUNDARY CONDITIONS
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dell-ocqa aronne
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Hi everybody

i'm trying to set a simple simulation with buoyantBuossinesqPimpleFoam, but i have a problem with the BC, especially with p_rgh and p. As far as i have understood for the p i have to set calculated since it is obtained as p=p_rgh+rhok*gh . The case is the following : a rectangular 2D column domain vertically oriented,with later impermeable walls, filled by water a T1 temperature. From below i inject at a constant rate water at a greater temperature T2.
Now for the BC at the bottom i will set

U-> fixedValue
T-> fixedValue
p->calcualted
p_rgh-> ?? which is better?? zeroGradient is it possible or not for this variable??

at the Top

U-> zeroGradient
T->zeroGradient
p->calculated
p_rgh-> ?? which is better?? fixedValue uniform=0 since it is in atmosphere?? is it possible??

it is convenient to set the z coordinate at the top of my domain so i get p_rgh=p+0 ?? and setting p_rgh=0 as BC i will not have additional problems??

at the lateral wall i set
U-> zeroGradient
T->zeroGradient
p->calculated
p_rgh-> zeroGradient it is ok??



Another question is about the meaning of the last step in the PIMPLE algorithm


p = p_rgh + rhok*gh;

if (p_rgh.needReference())
{
p += dimensionedScalar
(
"p",
p.dimensions(),
pRefValue - getRefCellValue(p, pRefCell)
);
p_rgh = p - rhok*gh;
}


where i specify the needReference() option?? and also the pRefValue and pRefCell?? I have to specify them or not??

Thanks so much to everybody!!
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Old   May 20, 2014, 08:24
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Joachim Herb
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pRefValue and pRefCell can be set in fvSolution:
http://www.openfoam.org/docs/user/fvSolution.php
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