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-   -   Dissabling turbulent dissipation (https://www.cfd-online.com/Forums/openfoam/78145-dissabling-turbulent-dissipation.html)

lindner July 14, 2010 04:10

Dissabling turbulent dissipation
 
Hi all,
I have a solver that calculates the local mean age of air, it's the simpleFoam solver with a scalarTransportFoam with source term = 1.
The code of the scalar transport is this

fvScalarMatrix ageEqn
(
fvm::ddt(age)
+ fvm::div(phi, age)
- fvm::laplacian(turbulence->nuEff(),age)
==
dimensionedScalar("ageSource", age.dimensions()*dimensionSet(0,0,-1,0,0), 1)
);

ageEqn.solve();

Now i want to test the local mean age solver but turning off the turbulent dissipation (turbulence->nuEff = 1).
I tried just removing the term from the equation but it didnt work. Is there a way to simple make the turbulent dissipation = 1 or add a simple constant?

Thanks

santos July 14, 2010 10:16

Hi there,

What if you replace it with:
- fvm::laplacian(Dage,age)
where Dage is the diffusivity of age (dont know whether it make sense!)

Dage will have to be declared in createFields.H, and then defined in constant/transportProperties.

Regards,
Jose Santos

lindner July 15, 2010 04:48

it worked!
Thanks for the help Jose, the code was implemented successfully.

Guilherme

HPE February 7, 2021 13:51

Set the term `alphaDt` to zero in these code blocks to turn off the turbulent diffusion contributions into the local mean age of air: https://www.cfd-online.com/Forums/op...tml#post795525


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