Week 8 - Simulation of a backward facing step in OpenFOAM

STEPS FOR SETTING UP THE SIMULATION WITHOUT GRADING FACTOR

BLOCKMESH FILE

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  9
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
    (0 0 0)
    (0.08 0 0)
    (0.08 0.005 0)
    (0 0.005 0)
    (0.08 .01 0)
    (0 0.01 0)
    (0.2 0.01 0)
    (0.2 0.005 0)
    (0.2 0 0)
    (0.2 -.01 0)
    (0.08 -.01 0)
    (0 0 0.1)
    (0.08 0 0.1)
    (0.08 0.005 0.1)
    (0 0.005 0.1)
    (0.08 .01 0.1)
    (0 0.01 0.1)
    (0.2 0.01 0.1)
    (0.2 0.005 0.1)
    (0.2 0 0.1)
    (0.2 -.01 0.1)
    (0.08 -.01 0.1)
);

blocks
(
    hex (0 1 2 3 11 12 13 14) (100 10 1) simpleGrading (1 1 1)
    hex (3 2 4 5 14 13 15 16) (100 10 1) simpleGrading (1 1 1)
    hex (2 7 6 4 13 18 17 15) (100 10 1) simpleGrading (1 1 1)
    hex (1 8 7 2 12 19 18 13) (100 10 1) simpleGrading (1 1 1)
    hex (10 9 8 1 21 20 19 12) (100 20 1) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
    inlet
    {
        type patch;
        faces
        (
            (0 11 14 3)
            (3 14 16 5)
        );
    }
    outlet
    {
        type patch;
        faces
        (
            (9 8 19 20)
            (8 7 18 19)
            (7 6 17 18)
        );
    }
    fixedWalls
    {
        type wall;
        faces
        (
            (4 5 16 15)
            (0 1 12 11)
            (6 4 15 17)
            (10 9 20 21)
            (1 10 21 12)
        );
    }
    frontAndBack
    {
        type empty;
        faces
        (
            (11 12 13 14)
            (14 13 15 16)
            (13 18 17 15)
            (12 19 18 13)
            (21 20 19 12)
            (0 3 2 1)
            (3 5 4 2)
            (2 4 6 7)
            (1 2 7 8)
            (10 1 8 9)
        );
    }
);

mergePatchPairs
(
);

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

controlDict file

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  9
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     icoFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         0.2;

deltaT          0.00001;

writeControl    timeStep;

writeInterval   20;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;


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

PRESSURE FILE

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  9
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform 0;

boundaryField
{
    inlet
    {
        type            zeroGradient;
    }
    outlet
    {
        type            fixedValue;
        value           uniform 0;
    }

    fixedWalls
    {
        type            zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }
}

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

VELOCITY FILE

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  9
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform (0 0 0);

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform (1 0 0);
    }
    outlet
    {
        type            zeroGradient;
    }
    fixedWalls
    {
        type            noSlip;
        value           uniform (0 0 0);
    }

    frontAndBack
    {
        type            empty;
    }
}

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

VELOCITY CONTOUR

PRESSURE CONTOUR

VELOCITY PROFILE AT 0.085 M FROM THE INLET OF THE STEPPED DUCT

VELOCITY PROFILE IN X,Y AND Z DIRECTION AT 0.085M FROM THE INLET OF THE STEPPED DUCT

PRESSURE PROFILES AT 0.085M FROM THE INLET OF THE STEPPED DUCT

CASE 2

whole blockMeshDict file will remain same only the grading is changes as given below

VELOCITY PROFILE AT 0.085 M FROM THE INLET OF THE STEPPED DUCT WITH 0.2 GRADING FACTOR

VELOCITY PROFILE IN X,Y,Z DIRECTIONS AT 0.085 M FROM THE STEPPED DUCT WITH 0.2 GRADING FACTOR

PRESSURE PROFILES AT 0.085 M FROM THE INLET OF THE STEPPED DUCT WITH 0.2 GRADING FACTOR