[nawa]

I have this weird thing going on what might be the reasons for it??
Case is simple setFields initialized slurry in comes down and mixes.
Solver is multiphaseInterFoam and boundaries are given below

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                  |
|   \\  /    A nd           | Website:  www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       volVectorField;
    location    "0";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    dome
    {
        type            noSlip;
    }
    inlet
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    inlet_pipe
    {
        type            noSlip;
    }
    outlet
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    walls
    {
        type            noSlip;
    }
	gas_outlet
	{
		type 			noSlip;
	}
	default_faces
	{
		type			empty;
	}
}


// ************************************************************************* //

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];
internalField   uniform 0;

boundaryField
{


inlet
{
    type            fixedValue;
    value           uniform 101325; // atmospheric pressure at inlet 
}
    outlet
    {

        type            fixedValue;
        value              uniform 101325;  // atmospheric pressure at outlet
    }

    gas_outlet
    {
        type            zeroGradient;
    }

    walls
    {
        type            zeroGradient;
    }
    
    inlet_pipe
    {
        type            zeroGradient;
    }
dome 
	{	
		 type           zeroGradient;
	}
defaultFaces
    {
        type            empty;
    }

}

// ************************************************************************* //

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      alpha.slurry;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];//kg m s K mol A cd

internalField   uniform 0;
boundaryField
{
    inlet
    {
        type           zeroGradient;
    }

    outlet
    {
        type           zeroGradient;
	}
    walls
    {
        type            zeroGradient;
    }
    inlet_pipe
    {
        type            zeroGradient;
    }
	dome
    {
        type           zeroGradient;
    }
	gas_outlet
    {
        type           zeroGradient;
    }
	defaultFaces
	{
	type		empty;
	}
}
// ************************************************************************* //

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      alpha.gas;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];//kg m s K mol A cd

internalField   uniform 0;
boundaryField
{
    inlet
    {
        type           zeroGradient;
    }

    outlet
    {
        type           zeroGradient;
    }

    walls
    {
        type            zeroGradient;
    }
    inlet_pipe
    {
        type            zeroGradient;
    }
	dome
    {
        type           zeroGradient;
    }
	gas_outlet
    {
        type           zeroGradient;
    }
defaultFaces
    {
        type            empty;
    }
}
// ************************************************************************* //

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  4.0                                  |
|   \\  /    A nd           | Website:  www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       volScalarField;
    location    "0";
    object      alpha.air;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 1;

boundaryField
{
    dome
    {
        type            zeroGradient;
    }
    inlet
    {
        type            zeroGradient;
    }
    inlet_pipe
    {
        type            zeroGradient;
    }
    outlet
    {
        type            zeroGradient;
    }
    walls
    {
        type            zeroGradient;
    }
	gas_outlet
    {
        type           zeroGradient;
    }
defaultFaces
    {
        type            empty;
    }
}


// ************************************************************************* //

[Yann]

Hello,

Could you elaborate on what you are simulating?

I see you have inlet/outlet/pipe_inlet/gas_outlet but it's hard to understand where it is on your geometry and what flow you want to generate.

Yann

[nawa]

Thank you Yann for the reply!

So basically the case is about the natural process of how slurry situated at let's say xyz height (shown in figure below ) flows through the pipe and mixes with the slurry at abc height (see in figure ) .

I have updated the image with the more details where all of the red texts were patches.

Also, let me remind you that the patch gas_outlet is not an outlet boundary condition for this case it's just a wall (sorry for the misinformation that one is there because I actually named it for the other simulation for which I need that patch and the mesh file I will be using is the same that I used here (I hope it clears out . please tell me if it didn't.))

boundaries are
inlet - atmosphere
outlet -atmosphere
gas_outlet - walls
inlet_pipe - walls
dome -walls
walls -walls

Also the simulation should stop when the all of the slurries at height xyz m completely comes down and settles.

I hope it clarifies.

Here is the link to the case file
https://drive.google.com/drive/folde...cF?usp=sharing