[Niazi]

Hi Foamers,

I am trying to read the pressure field from the mesh and then take a weighted average of pressure and using that I want to find the velocity on the inlet patch. to read the Pressure field I am using the following,

const volScalarField& pIn=db().lookupObject<volScalarField>("p");

then to take the weightedaverage
const volScalarField pAverage = pIn.weightedAverage(patch().boundaryMesh().mesh(). V());

and for velocity calculation

vectorField :: operator=(n_*pow(p1-pAverage)/rho,0.5));

but as I am new to OpenFOAM I don't understand how to properly implement that. I get the following error,


conversion from ‘Foam::dimensioned<double>’ to non-scalar type ‘const volScalarField’ {aka ‘const Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>’} requested
175 | const volScalarField pAverage = pIn.weightedAverage(patch().boundaryMesh().mesh(). V());

Can anyone please help me out here, I will be greatly thankful.

[Niazi]

Thanks to Alexeym, I was able to figure out the problem.

Originally Posted by alexeym

You call value method of the result of weightedAverage, i.e. pIn.weightedAverage(internalField().mesh().V()).va lue().

As I said pIn.mesh().C() is an array of cell centres, which are vectors, so if you call component method, you get component of a vector. If you want a value of a field, you use v() method.

This starts being personal consulting, which is not the aim of this forum. So, this is my last answer in private messages. Add you question in a forum post, so other people can benefit from answers.