[火山口玩泥巴]

Hi,
I'm a new foamer running a case in OpenFOAM (v2312) where I have trouble with solution convergence and bounding of k and omega.

The case is a transient 3d channel flow with one inflow and one outflow.

The solver I used in this case is interFoam because of the mutiphase.

I used blockMesh to build the mesh and simplified the mesh to make sure there are no problems for mesh qulities.(It has been checked by checkMesh)

For turbulence I'm using the k-omega SST model which is not so sensetive to the initial conditions (I'm not sure)

For boundary conditions (sry I can't the code function):

U:
```
inlet
{
type fixedValue;
value uniform (10 0 0);
}

walls
{
type noSlip;
}

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

outlet
{
type outletPhaseMeanVelocity;
Umean 15;
alpha alpha.water;
value $internalField;
}
```

p_rgh:
```
atmosphere
{
type totalPressure;
p0 uniform 0;
}

inlet
{
type zeroGradient;
}

outlet
{
type zeroGradient;
}

walls
{
type fixedFluxPressure;
value uniform 0;
}
```

k:
```
inlet
{
type fixedValue;
value $internalField;
}

walls
{
type kqRWallFunction;
value $internalField;
}

outlet
{
type inletOutlet;
value $internalField;
inletValue uniform 0;

}

atmosphere
{
type inletOutlet;
inletValue $internalField;
value $internalField;
}
```

omega:
```
inlet
{
type fixedValue;
value $internalField;
}

walls
{
type omegaWallFunction;
value $internalField;
}

outlet
{
type inletOutlet;
value $internalField;
inletValue uniform 0;

}

atmosphere
{
type inletOutlet;
inletValue $internalField;
value $internalField;
}
```

alpha.water:
```
inlet
{
type fixedValue;
value uniform 1;
}

walls
{
type zeroGradient;
}

outlet
{
type variableHeightFlowRate;
lowerBound 0;
upperBound 1;
value uniform 0;
}

atmosphere
{
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}
```

For initial conditions, I have set the k = 5, omega = 40, p_rhg = 0, when I set the U = 10 while setting a specific area of region alpha.water = 1 by setFields, it can run. However when I try to set the U = 0 or less area of region to be water, then the program will get divergency with reporting bonding omega and bonding k.

What is the reason for the problem mentioned above?
And how can I solve it? By resetting initial conditions of k and omega or something else?

[火山口玩泥巴]

Because I don't have the permission to post the picture, I can't show my mesh directly. So I put the code of blockMeshDict here:
```
scale 1;

vertices //
(
(0 0 0) //0
(28 0 0) //1
(0 2 0) //2
(28 2 0) //3
(48 2 0) //4
(0 3 0) //5
(28 3 0) //6
(48 3 0) //7
(0 7 0) //8
(28 7 0) //9
(48 7 0) //10
(0 16 0) //11
(28 16 0) //12
(48 16 0) //13


(0 0 6) //14
(28 0 6) //15
(0 2 6) //16
(28 2 6) //17
(48 2 6) //18
(0 3 6) //19
(28 3 6) //20
(48 3 6) //21
(0 7 6) //22
(28 7 6) //23
(48 7 6) //24
(0 16 6) //25
(28 16 6) //26
(48 16 6) //27
);

blocks
(
hex (0 1 3 2 14 15 17 16) (35 5 5) simpleGrading (1 1 1)

hex (2 3 6 5 16 17 20 19) (35 3 5) simpleGrading (1 1 1)

hex (3 4 7 6 17 18 21 20) (25 3 5) simpleGrading (1 1 1)

hex (5 6 9 8 19 20 23 22) (35 15 5) simpleGrading (1 1 1)

hex (6 7 10 9 20 21 24 23) (25 15 5) simpleGrading (1 1 1)

hex (8 9 12 11 22 23 26 25) (35 15 5) simpleGrading (1 1 1)

hex (9 10 13 12 23 24 27 26) (25 15 5) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
inlet
{
type patch;
faces
(
(8 5 19 22)
(5 2 16 19)
(2 0 14 16)
);
}
walls
{
type wall;
faces
(
(11 8 22 25)
(0 1 15 14)
(1 3 17 15)
(3 4 18 17)
(1 0 2 3)
(3 2 5 6)
(4 3 6 7)
(6 5 8 9)
(7 6 9 10)
(9 8 11 12)
(10 9 12 13)
(14 15 17 16)
(16 17 20 19)
(17 18 21 20)
(19 20 23 22)
(20 21 24 23)
(22 23 26 25)
(23 24 27 26)

);
}
outlet
{
type patch;
faces
(
(4 7 21 18)
(7 10 24 21)
(10 13 27 24)
);
}
atmosphere
{
type patch;
faces
(
(12 11 25 26)
(13 12 26 27)
);
}
);
```