[jcespada]

Hi all,

I'm struggling for some days with the simulation of a rotating shaft with a couple blades on it.

The rotating walls are "rotatingwalls" and "blades", the static walls are "staticwalls" and "staticwallslager".
There are open boundaries "inlet" and "outlet" (U -> zeroGradient and p = 0) and two periodic conditions.

I've tried to simulate the case with the SRFSimpleFoam solver. All boundary conditions work fine and the case converges, but the inlet and outlet do rotate as well and the results are crap. The air flows in the wrong direction.

This is my 0\Urel file:

boundaryField
{
inlet
{
type zeroGradient;
relative no;
}

outlet
{
type zeroGradient;
relative no;
}

rotatingwalls
{
type fixedValue;
value uniform ( 0 0 0 );
}

blades
{
type fixedValue;
value uniform ( 0 0 0 );
}

staticwalls
{
type SRFVelocity;
inletValue uniform ( 0 0 0 );
relative no;
value uniform ( 0 0 0 );
}

staticwallslager
{
type SRFVelocity;
inletValue uniform ( 0 0 0 );
relative no;
value uniform ( 0 0 0 );
}

cyclic_half0
{
type cyclic;
}

cyclic_half1
{
type cyclic;
}
}

When I use the MRFSimpleFoam solver the inlet and outlet bc's are fine and the flow seems ok, but when I check the wall velocities, I see that the static walls rotate as well. I use the simpleFoam solver. The fvOptions file is as follows:

MRF1
{
type MRFSource;
active true;
selectionMode cellZone;
cellZone part_3-solid;

MRFSourceCoeffs
{
nonRotatingPatches (staticwalls, staticwallslager, inlet, outlet);

origin (0 0 0);
axis (1 0 0);
omega 52.36;
}
}

In controlDict I use

application simpleFoam;

and the file 0/U

boundaryField
{
inlet
{
type zeroGradient;
}

outlet
{
type zeroGradient;
}

rotatingwalls
{
type fixedValue;
value uniform ( 0 0 0 );
}

blades
{
type fixedValue;
value uniform ( 0 0 0 );
}

staticwalls
{
type fixedValue;
value uniform ( 0 0 0 );
}

staticwallslager
{
type fixedValue;
value uniform ( 0 0 0 );
}

cyclic_half0
{
type cyclic;
}

cyclic_half1
{
type cyclic;
}
}

I would be glad if somebody could explain me what I'm doing wrong in any of both cases (or both).

Thanks in advance.

[jcespada]

Putting it in another way. Isn't it possible to use SRFSimpleFoam with a pressure boundary condition at the inlet which doesn't rotate?
What would then this condition be in the 0/Urel file?

[masterd-@gmx.de]

Hi jcespada,

could you solve your Problem? I have a similar one. I think it is important what kind of pressure BCs you set in relation to the velocity BCs, so I think there is a relation between them.

Greetings