Inlet and Outlet
 

Hi All

I am trying to setup a simple case with an Inlet and an Outlet.

I am used to WinAir, where you only input a Volumetric Flow (m3/s) and a directional Vector.

I am reviewing the Derived Patch Field Types...but I am confused about which one to use.

Could anyone help me on that?

Thanks

Another question I have is about the relationship between solvers and the different Patch Field Types.( I am using buoyanBoussinesqSimpleFoam, and the other steady state solver dealing with heat Transfer for buoyancy driven flows...)
Can I use anyone of the patch fields described in page U-133 ? or are they linked to a precise solver?

Thanks

Luis Blanes

Errors regarding Inlet and Outlet
 

Hello all
I tried to run a simulation with the following values at the U/0 directory

boundaryField
{
warm
{
type fixedValue;
value uniform (0 0 0);
}

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

defaultFaces
{
type fixedValue;
value uniform (0 0 0);
}
inlet
{
type fixedValue;
value uniform (0 0 -1);
}

outlet
{
type fixedValue;
value uniform (0 0 1);


And I got that error.
Can somebody please help me?
Thanks
Can I input just two velocities in a patch just typing that in the U/0 directory??
Can the velocity vector point outside the domain??
Thanks


Starting time loop

Time = 0.1

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.00451649, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 8.88538e-17, No Iterations 1
#0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted:
#3 Foam::DILUPreconditioner::calcReciprocalD(Foam::Fi eld<double>&, Foam::lduMatrix const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#4 Foam::DILUPreconditioner::DILUPreconditioner(Foam: :lduMatrix::solver const&, Foam::dictionary const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#5 Foam::lduMatrix::preconditioner::addasymMatrixCons tructorToTable<Foam::DILUPreconditioner>::New(Foam ::lduMatrix::solver const&, Foam::dictionary const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#6 Foam::lduMatrix::preconditioner::New(Foam::lduMatr ix::solver const&, Foam::dictionary const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#7 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#8 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libfiniteVolume.so"
#9
in "/opt/openfoam171/applications/bin/linuxGccDPOpt/buoyantBoussinesqSimpleFoam"
#10 __libc_start_main in "/lib/libc.so.6"
#11
in "/opt/openfoam171/applications/bin/linuxGccDPOpt/buoyantBoussinesqSimpleFoam"
Floating point exception
;

Try to use zeroGradient for your outflow. Is the direction of the velocity in your inlet ok?

Thanks The King.
Yes, the direction in the Inlet makes no sense.

I guess that you only need to input a velocity in the inlet and zeroGradient in the outlet.

Thanks

Inlet velocity is ok....
 

I have checked the case again...
I use buoyantBoussinesqSimpleFoam

Can anyone tell me how to input a simple Inlet and Outlet in using heatTransfer solvers?

U at inlet is ok (0 0 -1) as it is pointing inside the domain (can I use negative numbers?)

Thanks in advance
-----------------------------------------------------
boundary file

5
(
warm
{
type wall;
nFaces 390;
startFace 90580;
}
cool
{
type wall;
nFaces 390;
startFace 90970;
}
inlet
{
type patch;
nFaces 1;
startFace 91360;
}
outlet
{
type patch;
nFaces 1;
startFace 91361;
}
defaultFaces
{
type wall;
nFaces 5270;
startFace 91362;
}
----------------------------------------------------
U/0

dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
warm
{
type fixedValue;
value uniform (0 0 0);
}
cool
{
type fixedValue;
value uniform (0 0 0);
}
defaultFaces
{
type fixedValue;
value uniform (0 0 0);
}
inlet
{
type fixedValue;
value uniform (0 0 -1);
}
outlet
{
type zeroGradient;
{
}
----------------------------------------------------

p/0

dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
warm
{
type buoyantPressure;
rho rhok;
value uniform 0;
}
cool
{
type buoyantPressure;
rho rhok;
value uniform 0;
}
defaultFaces
{
type buoyantPressure;
rho rhok;
value uniform 0;
}
inlet
{
type buoyantPressure;
rho rhok;
value uniform 0;
}
outlet
{
type buoyantPressure;
rho rhok;
value uniform 0;
}
}

Hi lmblanes

Just wondering a little about your pressure setup. You might try keeping the outlet/internalField at uniform 0 and setting the rest to zeroGradient. My experience is only really with simpleFoam, so I hope this helps.
Also, yes you can use negative numbers for velocity as long as you're sure its in the right direction.

Dom

Thanks!
I have seen lots of cases where there is an Inlet and the "Outlet" is just a free pressure boundary...

What do you mean with "in the right direction"? Is there some rule?

I wonder if I can do something like this

________________
I I
I I
Inlet(1m3/s) ---> Outlet(0.9 m3/s) --->
I I
I I
I Opening to atmosphere
I_______________ I

Thanks