[arashgmn]

What is the difference between pressureInletUniformVelocity and pressureInletVelocity?

Based on the source code for the first one we have:

operator==(patch().nf()*gSum(patch().Sf() & *this)/gSum(patch().magSf()));

and for the second one

operator==(n*phip/magS);

in which n and magS are defined as before:

tmp<vectorField> n = patch().nf(); 
const Field<scalar>& magS = patch().magSf();

Can someone explain how does gSum work and what difference does it make?

[jherb]

The first one applys the area averaged value of the velocities of the faces of the patch (so one value) to all faces of the patch. For each face of the patch the velocity vector is in the direction of the face normal vectors.


The second one sets different velocity values (again in the direction of the face normals) based on the calculated flux values.

[arashgmn]

Originally Posted by jherb

The first one applys the area averaged value of the velocities of the faces of the patch (so one value) to all faces of the patch. For each face of the patch the velocity vector is in the direction of the face normal vectors.


The second one sets different velocity values (again in the direction of the face normals) based on the calculated flux values.

Thanks Joachim. It resolved my confusion.