Week 12 - Validation studies of Symmetry BC vs Wedge BC in OpenFOAM vs Analytical H.P equation

Aim: To validate the studies of symmetry boundary condetion vs Wedge boundary condetion in OpenFoam vsAnalytical H.P Equaion

Objective:-

• To Validate the hydrodynamic length with the numerical Resulta
• To Validate the fully devoloped flow velocity profile with its analytical profile
• To validate maximum velocity and pressured dropfor fully devolopd flow
• Tp post process the shear stress and to validate wall shear stress for fully devoloped flow

Symmetry Boundary Condetion

Symmety boundary cocondetion defines the mirror surface. By using symmetrynboundary condetion the flow domain can be essentially halved reducing the tome to achive a solution. In symmetry boundary condetion

• The fluxes across the symmetry are zero
• The normal componets of all variables are set to zero

Wedge boundary condetion

Wedge boundary condetion is used only during axisymmetric situation. The model and flow must be axisymmetric along the centaral line. but it only work for 2D simulation.

blockMeshDict

vertices
(
    (0 0 0)//Vertex0
    (0 3.999048 -0.087260)//Vertex1
    (0 3.999048 0.087260)//Vertex2
    (2.0000e-01 0 0)//Vertex3
    (2.0000e-01 0.003985 -0.000349)//Vertex4
    (2.0000e-01 0.003985 -0.000349)//Vertes5
    
);

blocks
(
    hex (0 1 2 0 3 4 5 3) (50 1 400) simpleGrading (0.1 1 10)
);

edges
(
	arc 1 2 (0 4.0000e-03 0)
	arc 4 5 (2.0000e-01 4.0000e-03 0)
);

boundary
(
    axis
    {
        type empty;
        faces
        (
            (0 3 3 0)
        );
    }
    inlet
    {
        type patch;
        faces
        (
            (0 0 2 1)
            
        );
    }
    wall
    {
        type wall;
        faces
        (
            (2 5 4 1)
            
        );
    }
    outlet
    	(
    		(3 4 5 3)
    	);
    }
    front
    {
    	type wedge;
    	faces
    	(
    		(0 3 5 2)
    	);
    }
    back
    {
         type wedge;
         faces
         (
         	(0 1 4 3)
         );
    }


);

mergePatchPairs
(
);

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

ControlDict

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     icoFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         20;

deltaT          0.01;

writeControl    timeStep;

writeInterval   2000;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;


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

Velocity

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform (0.50929 0 0);

boundaryField
{
    axis
    {
        type            empty;
        
    }

    inlet
    {
        type            fixedValue;
        value           uniform(0.50929 0 0 );
    }

    wall
    {
        type            fixedvalue;
        value            uniform (0 0 0);
    }
    outlet
    {
        type            inletOutlet;
        inletValue      uniform (0.50929 0 0);
        value            uniform (0.50929 0 0);
    }
    front
    {
    	type            wedge;
    }
    back
    {
    	type            wedge;
    }
    
}

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

Pressure

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  8
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    axis
    {
        type            empty;
    }

    inlet
    {
        type            zeroGradient;
    }

    wall
    {
        type            zeroGradient;
    }
    outlet
    {	type            fixedValue;
        value           uniform 10;
    }
    front
    {
    	type symmetry;
        faces
        (
               (0 3 5 2)
        );
    }
    back
    	type symmetry;
        (
               (0 1 4 3)
        );

    	
    }
}

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

Velocity at inlet

Velocity at outlet