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-   -   Selecting numerical schemes for temperature equation (http://www.cfd-online.com/Forums/openfoam-pre-processing/62196-selecting-numerical-schemes-temperature-equation.html)

maka May 21, 2006 13:35

I'm solving a case with transi
 
I'm solving a case with transient coupled (trough buoyancy term) momentum and energy equation (temperature eq, boussinesq assumption). I need some comment on my selection of fvSchemes. I need to apply central difference for convective and viscous terms together with Crank Nicholson for time.

I read:
http://www.opencfd.co.uk/openfoam/do...#x20-1050004.4

but I have two questions:

a) how does fluxRequired dictionary in fvSchemes affect the calculation? Should I put T there also? Note: I'm familiar with PISO except for the part of interpolation to surface.

b) Should I put a limiter on T?

you are welcome to give any comments on the following selections:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default CrankNicholson 1;
}

gradSchemes
{
default none; //Gauss linear;
grad(p) Gauss linear;
grad(U) Gauss linear;
}

divSchemes
{
default none;
div(phi,U) Gauss linear;
div(phi,T) Gauss linear; // energy equation. Gauss limitedLinear 1
}

laplacianSchemes
{
default none;
laplacian(nu,U) Gauss linear corrected;
laplacian(1|A(U),p) Gauss linear corrected;
laplacian(alpha,T) Gauss linear corrected; // energy equation.
//alpha: thermal diffussivity.
}

interpolationSchemes
{
default linear;
interpolate(U) linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p;
T;
}


// ************************************************** *********************** //

best regards,
Maka.


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