Week 12 - Validation studies of Symmetry BC vs Wedge BC in OpenFOAM vs Analytical H.P equation
AIM : TO SIMULATE THE WEDGE FLOW USING THE OPEN FOAM FOR DIFFERENT ANGLES OF WEDGE AND TO CAPTURE THE RESULTS THAT.
THE GIVEN ANGLES FOR THE FLOW ARE
10
25
45
simulation flow through a pipe from open foam
objective:
- the main objective of the project is to simulate the flow through the pipe in OPEN FOAM software.
- we have to write the program fro the generation of the blockmeshdict file, or computational mesh for wedge angle and grading scheme.
- calculate the length of the pipe using the entry length formula through the laminar flow through the pipe.
- show that the entry length is enough for producing the fully developed flow.
- and we have to compare the velocity profile at the different lengths of the pipe.
- we have to show our velocity profile is fully developed.
- post-process velocity and shear stress.
CODE:
AMGLE 10:
BLOCKMESHDICT:
/*--------------------------------*- 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;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// blockMesh parameterization
/* Geometrical Info */
D 0.004; // Diameter
r #calc "0.5*$D"; // Radius
angle 10; // Angle in degrees
theta #calc "degToRad($angle)"; // Angle in radians
Re 100; // Reynolds Number
Le #calc "0.06*$Re*$D"; // Entrance Length
L #calc "0.2 + $Le"; // Total length of pipe
/* Vertices Info */
xmin 0;
xmax $L;
ymax #calc "$r*cos($theta)";
zmax #calc "$r*sin($theta)";
zmin #calc "-$r*sin($theta)";
curve #calc "$r*cos($theta)+1e-4";
/* Mesh Info */
nx 10; // Cells along local X
ny 1; // Cells along local Y
nz 50; // Cells along local Z
gx 0.2; // SG along local X
gy 1; // SG along local Y
gz 1; // SG along local Z
convertToMeters 1;
vertices
(
($xmin 0 0) //0
($xmin $ymax $zmax) //1
($xmin $ymax $zmin) //2
($xmax 0 0) //3
($xmax $ymax $zmax) //4
($xmax $ymax $zmin) //5
);
blocks
(
hex (0 2 1 0 3 5 4 3) ($nx $ny $nz) simpleGrading ($gx $gy $gz)
);
edges
(
arc 1 2 ($xmin $curve 0)
arc 4 5 ($xmax $curve 0)
);
boundary
(
inlet
{
type patch;
faces
(
(0 1 2 0)
);
}
outlet
{
type patch;
faces
(
(3 5 4 3)
);
}
front
{
type symmetry;
faces
(
(0 3 4 1)
);
}
back
{
type symmetry; // symmetry
faces
(
(0 2 5 3)
);
}
wall
{
type wall; // symmetry
faces
(
(2 1 4 5)
);
}
axis
{
type empty;
faces
(
(0 3 3 0)
);
}
);
mergePatchPairs
(
);
// ************************************************************************* //ANGLE 25
BLOCKMESHDICT:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 9
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// blockMesh parameterization
/* Geometrical Info */
D 0.004; // Diameter
r #calc "0.5*$D"; // Radius
angle 25; // Angle in degrees
theta #calc "degToRad($angle)"; // Angle in radians
Re 100; // Reynolds Number
Le #calc "0.06*$Re*$D"; // Entrance Length
L #calc "0.2 + $Le"; // Total length of pipe
/* Vertices Info */
xmin 0;
xmax $L;
ymax #calc "$r*cos($theta)";
zmax #calc "$r*sin($theta)";
zmin #calc "-$r*sin($theta)";
curve #calc "$r*cos($theta)+1e-4";
/* Mesh Info */
nx 10; // Cells along local X
ny 1; // Cells along local Y
nz 50; // Cells along local Z
gx 0.2; // SG along local X
gy 1; // SG along local Y
gz 1; // SG along local Z
convertToMeters 1;
vertices
(
($xmin 0 0) //0
($xmin $ymax $zmax) //1
($xmin $ymax $zmin) //2
($xmax 0 0) //3
($xmax $ymax $zmax) //4
($xmax $ymax $zmin) //5
);
blocks
(
hex (0 2 1 0 3 5 4 3) ($nx $ny $nz) simpleGrading ($gx $gy $gz)
);
edges
(
arc 1 2 ($xmin $curve 0)
arc 4 5 ($xmax $curve 0)
);
boundary
(
inlet
{
type patch;
faces
(
(0 1 2 0)
);
}
outlet
{
type patch;
faces
(
(3 5 4 3)
);
}
front
{
type symmetry;
faces
(
(0 3 4 1)
);
}
back
{
type symmetry; // symmetry
faces
(
(0 2 5 3)
);
}
wall
{
type wall; // symmetry
faces
(
(2 1 4 5)
);
}
axis
{
type empty;
faces
(
(0 3 3 0)
);
}
);
mergePatchPairs
(
);
// ************************************************************************* //ANGLE 45
BLOCKMESHDICT:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 9
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// blockMesh parameterization
/* Geometrical Info */
D 0.004; // Diameter
r #calc "0.5*$D"; // Radius
angle 45; // Angle in degrees
theta #calc "degToRad($angle)"; // Angle in radians
Re 100; // Reynolds Number
Le #calc "0.06*$Re*$D"; // Entrance Length
L #calc "0.2 + $Le"; // Total length of pipe
/* Vertices Info */
xmin 0;
xmax $L;
ymax #calc "$r*cos($theta)";
zmax #calc "$r*sin($theta)";
zmin #calc "-$r*sin($theta)";
curve #calc "$r*cos($theta)+1e-4";
/* Mesh Info */
nx 10; // Cells along local X
ny 1; // Cells along local Y
nz 50; // Cells along local Z
gx 0.2; // SG along local X
gy 1; // SG along local Y
gz 1; // SG along local Z
convertToMeters 1;
vertices
(
($xmin 0 0) //0
($xmin $ymax $zmax) //1
($xmin $ymax $zmin) //2
($xmax 0 0) //3
($xmax $ymax $zmax) //4
($xmax $ymax $zmin) //5
);
blocks
(
hex (0 2 1 0 3 5 4 3) ($nx $ny $nz) simpleGrading ($gx $gy $gz)
);
edges
(
arc 1 2 ($xmin $curve 0)
arc 4 5 ($xmax $curve 0)
);
boundary
(
inlet
{
type patch;
faces
(
(0 1 2 0)
);
}
outlet
{
type patch;
faces
(
(3 5 4 3)
);
}
front
{
type symmetry;
faces
(
(0 3 4 1)
);
}
back
{
type symmetry; // symmetry
faces
(
(0 2 5 3)
);
}
wall
{
type wall; // symmetry
faces
(
(2 1 4 5)
);
}
axis
{
type empty;
faces
(
(0 3 3 0)
);
}
);
mergePatchPairs
(
);
// ************************************************************************* //
CONTROLDICT:
/*--------------------------------*- 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 5;
deltaT 0.001;
writeControl timeStep;
writeInterval 500;
purgeWrite 0;
writeFormat ascii;
writePrecision 6;
writeCompression off;
timeFormat general;
timePrecision 6;
runTimeModifiable true;
// ************************************************************************* //Pressure:
/*--------------------------------*- 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;
}
front
{
type symmetry; // symmetry
}
back
{
type symmetry; // symmetry
}
wall
{
type zeroGradient;
}
axis
{
type empty;
}
}
// ************************************************************************* //Velocity:
/*--------------------------------*- 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 (0.0223169508525577 0 0);
}
outlet
{
type zeroGradient;
}
front
{
type symmetry; // symmetry
}
back
{
type symmetry; // symmetry
}
wall
{
type noSlip;
}
axis
{
type empty;
}
}
// ************************************************************************* //Physical properties:
/*--------------------------------*- 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 "constant";
object transportProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
nu [0 2 -1 0 0 0 0] 8.9267803410231e-07;
// ************************************************************************* //OUTPUTS:
ANGLE 10:
MESH:
VELOCITY:
PRESSURE:
VELOCITY PLOT:
SHEAR STRESS PLOT:
COMPARISON OF ANALYTICAL AND TAU:
ANGLE 25:
MESH:
VELOCITY:
PRESSURE:
VELOCITY PLOT:
SHEAR STRESS:
COMPARISON OF TAU AND ANALYTICAL:
ANGLE 45:
VELOCITY:
PRESSURE:
VELOCITY PLOT:
SHEAR STRESS:
COMPARISON OF TAU AND ANALYTICAL
CONCLUSION:
We can observe there is no much change in the maximum velocities. The only difference observed is execution time a little high than type-wedge. While the angle increases the error in the maximum velocity is decreased. Though there is not much difference between analytical and numerical results and also with increasing the angle of the wedge, The Courant number is slightly increasing. we can say that the symmetric boundary condition plays an important role in terms of accuracy in the result.