[ywem]

Dear Foamers,
I am working on solving an equation like

fvm::ddt(M)
+fvm::div(phi, M)
==
-(M-M0)/tau

where tau is a constant, M and M0 are volVectorField. M0 is calculated by M0=H*tem1/mag(H), here I calculate tem1 as follows,

scalarField tem1(0.0);
forAll(H,i)
{
tem1[i] = 1.0/Foam::tanh(gamma.value()*mag(H).ref()[i])-1.0/(gamma.value()*mag(H).ref()[i]);
}

H is a volVectorField. M, M0, and H are defined in the file createFields.H. But when I typed

M0=H*tem1/mag(H)

and compiled, the following error occur,

error: no match for ‘operator*’ (operand types are ‘Foam::tmp<Foam::GeometricField<Foam::Tensor<doubl e>, Foam::fvPatchField, Foam::volMesh> >’ and ‘Foam::scalarField {aka Foam::Field<double>}’)

It seems that tem1 must be a geometricField. Can anyone help me for this problem? Thanks in advance.

[wangsen992]

Originally Posted by ywem

scalarField tem1(0.0);
forAll(H,i)
{
tem1[i] = 1.0/Foam::tanh(gamma.value()*mag(H).ref()[i])-1.0/(gamma.value()*mag(H).ref()[i]);
}

H is a volVectorField. M, M0, and H are defined in the file createFields.H. But when I typed

M0=H*tem1/mag(H)

Hi there,

I'm new to the code part of OpenFOAM but I will try to help with the best of my understanding.

If you go back to section 3.2.1 of the programmer's guide, you will see that scalarField is only a typedef-declared class name for List<Type>, which is distinctively different from geometricField<Type>. The problem here lies in the fact that there is no way for the operator to match the values since one is a List while the other includes the mesh.

The solution here, I suppose, is to initiate tem1 in 0/ directory as well, and initialize it with the equation you used.

Another solution is to use the static function (geometricField<Type>::New())[https://www.openfoam.com/documentati...b1bfde253137a] and calculate your tem1.

I hope this would give some ideas.

Cheers!

[ywem]

Originally Posted by wangsen992

Hi there,

I'm new to the code part of OpenFOAM but I will try to help with the best of my understanding.

If you go back to section 3.2.1 of the programmer's guide, you will see that scalarField is only a typedef-declared class name for List<Type>, which is distinctively different from geometricField<Type>. The problem here lies in the fact that there is no way for the operator to match the values since one is a List while the other includes the mesh.

The solution here, I suppose, is to initiate tem1 in 0/ directory as well, and initialize it with the equation you used.

Another solution is to use the static function (geometricField<Type>::New())[https://www.openfoam.com/documentati...b1bfde253137a] and calculate your tem1.

I hope this would give some ideas.

Cheers!

Dear Wang,
Thank you for your reply.
I think your first method works well.