CFD Online Discussion Forums - Accessing Themo Data on a Boundary Patch

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Accessing Themo Data on a Boundary Patch

Hello

Simple-ish question, this. I'm writing a boundary condition for reactingFoam. Typically, when I want to get values on said boundary, I do something like this,

Code:

const fvPatchField<scalar>& p = patch().lookupPatchField<volScalarField, scalar>("p");

const fvPatchField<vector>& U = patch().lookupPatchField<volVectorField, vector>("U");

Which works fine (see endless examples in $FOAM_SRC/finiteVolume/fields/fvPatchFields/derived).

I can't seem use this method to get the specific heat, Cp. If I try I get the error,

Code:

--> FOAM FATAL ERROR: 

    request for volScalarField Cp from objectRegistry region0 failed

    available objects of type volScalarField are

followed by a list of all the variables I can access this way. Cp is not in said list.

Does anyone know how can I get Cp (and by extension other thermophysical data) on a boundary patch in this sort of context?

Many thanks in advance

Bump. Still none the wiser. Anyone? Is this even possible? How about getting thermophysical values in the cells adjacent to the boundary?

I think Cp is one of those that needs to be calculated from your mixture. You might need to do something like this (this is rough pseudocode ).

Code:

fvPatchField<scalarField> Cp = 0;

forAll(Y,specI)

{

    Cp+=Y[speci].thePatchFieldYouWant*Cp.listOfSpecies[index for specI]

}

I think Cp lives in thermo somewhere, but I'm not 100% sure. Maybe look up a BC for alpha or alphat, as I think that would have access to what you need.

Hello

I know this is an old post. Just in case..

I guess you need to add 'Cp' as a volScalarField in createFields.H file and update it every iteration.

Hope this helps.