[li_hledm]

Hi Foamers,

I just got a question regarding imposing the periodic BC and the pressure gradient implementation.

My flow is as the figure attached where the water flows in against the pipe wall and the crude oil comes in from the centre core. I've set three pairs of periodic(cyclic) BCs.

Several questions here:

1. I saw the reference that there's a way to mimic the pressure gradient and drive the flow by specifying the mass flow rate, can anyone show me the syntax of specifying a mass flow rate? I saw the syntax of the meanVelocityForce :


pressureGradient
{
type meanVelocityForce;
active true;

selectionMode all;

meanVelocityForceCoeffs
{
selectionMode all; // Apply force to all cells
fields (U); // Name of velocity field
Ubar (0.5 0 0); // Desired mean velocity
relaxation 1; // Optional relaxation factor
}

}

Or the syntax of momentumSource(my guess is they are identical):
//momentumSource
//{
// type meanVelocityForce;

// selectionMode all;

// fields (U);
// Ubar (0.5 0 0);
//}

2. if the two phases of flow in my case have different flow rates (this can be easily done if to work with velocity inlets), is it possible to impose different mass flow rate for different phases, if yes and how?

I appreciate your help!

Thanks!