CFD Online Discussion Forums

Hi all,

I try to use advective boundary condition with icoFoam (incompressible) in a 2D simulation with OF 1.6.x. here's how I declare it in 0/U file :

Code:

boundaryField

{

    outlet

    {

        type            advective;

        phi             phi;

    }

    frontAndBack

    {

        type            empty;

    }

}

But at the end of the simulation 'value uniform (0 0 0);' has been added and I don't know why :

Code:

boundaryField

{

    outlet

    {

        type            advective;

        value           uniform (0 0 0);

    }

    frontAndBack

    {

        type            empty;

    }

}

Is it the right way to use this BC? Is it the same explanation that has been written in the following thread #18-19 ? (for a cyclic boundary condition) :
http://www.cfd-online.com/Forums/ope...condition.html
Right now, when I use the advective BC, my BC behaves like a wall with a no-slip condition which is totally different of what I expected... Should the advective BC acts like a non reflective boundary condition?? According to the source code description it is supposed to implement the following equation at the BC : DDt(psi, U) = 0 If anybody has an explanation of what I did wrong, please let me know!

Thank you very much,
Pascal