[stopherkri]

Hello guys,

I'm trying to model a 3d spillway using the interFoam solver, everything is running smoothly until the point when water reaches the outlet. It seems like it's not flowing out freely, it appers to be bouncing back at the outlet, I'm getting negative outflow at the patch.
Maybe I'm not setting correctly my boundary conditions. Hope you can help me out.

This are my initial conditions

alpha.water
boundaryField
{
inlet
{
type fixedValue;
value uniform 1;
}
outlet
{
type zeroGradient;
}
atmosphere
{
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}
walls
{
type zeroGradient;
}
}

U
boundaryField
{
inlet
{
type flowRateInletVelocity;
volumetricFlowRate constant 0.015811388;
}
outlet
{
type inletOutlet;
inletValue uniform (0 0 0);
value $internalField;
}

walls
{
type noSlip;
}
atmosphere
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}

}

p_rgh
boundaryField
{
inlet
{
type fixedFluxPressure;
value uniform 0;
}

outlet
{
type totalPressure;
p0 uniform 0;
value uniform 0;
}

walls
{
type fixedFluxPressure;
value uniform 0;
}
atmosphere
{
type totalPressure;
p0 uniform 0;
value uniform 0;
}
}

[michael_h]

You have specified zero outlet velocity. If you specify a constant pressure then you need "type zeroGradient" for the U field.

Originally Posted by stopherkri

Hello guys,

outlet
{
type inletOutlet;
inletValue uniform (0 0 0);
value $internalField;
}
}

[AtoHM]

That is not correct, inletOutlet acts as a zeroGradient condition in outflow direction and applies inletValue when backflow happens.


I checked out one of the interFoam tutorials \tutorials\multiphase\interFoam\RAS\waterChannel, It uses fixedFluxPressure for outlet instead of totalPressure.