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
Given Angles
10
25
45
Objective:
To write a program for 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 formulat through the laminar flow through the pipe
Show that the entry length is enough for producing the fully developed flow
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
Laminar Flow through a Pipe
Hydrodynamic Length (Le)
Diamter of the Pipe
D=10mm=0.001m
Re=2100
Le=12.6m
Vavg=0.1869m/s
Delta P =32.mu.LV/D^2
Delta P=0.0789 m^2/s
Vmax=2.Vavg
Vmax=0.3738 m/s
Program that Creats blockMesgDict file using Matlab
close all
clc
theta=25; %input('Input the Wedge Angle=');
theta=theta/2;
L=1.5;
d=0.01;
r=d/2;
height_wedge=r*cosd(theta);
width_wedge=r*sind(theta);
b1='/*----------------------*-C++-*----------------------------------*';
b2='========= | ';
b3=' \\ / F ield | OpenFOAM: The Open Source CFD Toolbox';
b4=' \\ / O peration | Website: https://openfoam.org ';
b5=' \\ / A nd |Version: 7 ';
b6=' \\/ M anipulation | ';
b7='\*----------------------------------------------------------------';
f1=fopen('blockMeshDict','w');
fprintf(f1,'%s\n',b1);
fprintf(f1,'%s\n',b2);
fprintf(f1,'%s\n',b3);
fprintf(f1,'%s\n',b4);
fprintf(f1,'%s\n',b5);
fprintf(f1,'%s\n',b6);
fprintf(f1,'%s\n',b7);
fprintf(f1,'FoamFile n{ n version 2.0; n format ascii;n class dictionary;n object blockMeshDict;n}');
b8=('//* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *');
fprintf(f1,'n%s n',b8);
fprintf(f1,'nconverToMeters 1;');
fprintf(f1,'nnvertices n(nn');
fprintf(f1,'(0 0 0)');
fprintf(f1,'n(0 0 0');
ver3=zeros(1,3);
ver4=zeros(1,3);
ver3(2)=height_wedge;
ver3(3)=width_wedge;
fprintf(f1,'n(%f %f %f)',ver3);
fprintf(f1,'n(%f %f %f)nn',ver4);
fprintf(f1,'(1.5 0 0 )');
fprintf(f1,'n(1.5 0 0 )');
ver3=zeros(1,3);
ver4=zeros(1,3);
ver3(1)=L;
ver3(2)=height_wedge;
ver3(3)=-width_wedge;
ver4(1)=L;
ver4(2)=height_wedge;
ver4(3)=width_wedge;
fprintf(f1,'n (%d %f %f)',ver3);
fprintf(f1,'n(%d %f %f)n',ver4);
fprintf(f1,'n);nn');
fprintf(f1,'blocksn(n');
fprintf(f1,' hex(0 1 2 3 4 5 6 7 (1 20 100) simpleGrading (1 0.4 1) n); nedges (n);n');
fprintf(f1,'bounadry n(n top n {n typewall; n faces n ( n (2 3 7 6)n ); n }');
fprintf(f1,'bottom n {n type empty; n faces n ( n (2 3 7 6)n ); n} ');
fprintf(f1,' frontwedge n { n type wedge;n faces n (n (0 4 7 3)n );n }');
fprintf(f1,'n backwedge n {n type wedge;n faces n (n (1 2 6 5)n );n }');
fprintf(f1,'n inlet n {n type patch; n faces n (n (1 0 3 2)n);}');
fprintf(f1, 'n outlet n{n type patch;n faces n (n (5 6 7 4)n );n}');
fprintf(f1,'n); nmergePatchPairs n(n);');
bp=('//****************************************************//');
fprintf(f1,'nn%s',b9);
fclose(f1);
blockMeshdict file that creats the wedge of angle 10
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
convertToMeters 1;
vertices
(
(0 0 0)
(0 0 0)
(0.00000 0.004981 -0.00436)
(0.00000 0.004981 0.000436)
(1.5 0 0)
(1.5 0 0)
(1.500000e+00 0.004981 -0.000436)
(1.500000e+00 0.004981 0.000436)
);
blocks
(
hex(0 1 2 3 4 5 6 7) (1 20 100) simpleGrading (1 0.4 1)
);
edges
(
);
boundary
(
top
{
type wall;
faces
(
(2 3 7 6)
);
}
bottom
{
type empty;
faces
(
(1 5 4 0)
);
}
frontedge
{
type wedge;
faces
(
(0 4 7 3)
);
}
backwedge
{
type wedge;
faces
(
(1 2 6 5)
);
}
inlet
{
type patch;
faces
(
(1 0 3 2)
);
}
outlet
{
type patch;
faces
(
(5 6 7 4)
);
}
);blockmeshdict file that creates the wedge angle of 25
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
convertToMeters 1;
vertices
(
(0 0 0)
(0 0 0)
(0.00000 0.004881 -0.001082)
(0.00000 0.004881 0.001082)
(1.5 0 0)
(1.5 0 0)
(1.500000e+00 0.004881 -0.001082)
(1.500000e+00 0.004881 0.001082)
);
blocks
(
hex(0 1 2 3 4 5 6 7) (1 20 100) simpleGrading (1 0.4 1)
);
edges
(
);
boundary
(
top
{
type wall;
faces
(
(2 3 7 6)
);
}
bottom
{
type empty;
faces
(
(1 5 4 0)
);
}
frontedge
{
type wedge;
faces
(
(0 4 7 3)
);
}
backwedge
{
type wedge;
faces
(
(1 2 6 5)
);
}
inlet
{
type patch;
faces
(
(1 0 3 2)
);
}
outlet
{
type patch;
faces
(
(5 6 7 4)
);
}
);blockmeshdict file that creates the wedge of angle 45
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
convertToMeters 1;
vertices
(
(0 0 0)
(0 0 0)
(0.00000 0.004619 -0.001913)
(0.00000 0.004619 0.001913)
(1.5 0 0)
(1.5 0 0)
(1.500000e+00 0.004619 -0.001913)
(1.500000e+00 0.004619 0.001913)
);
blocks
(
hex(0 1 2 3 4 5 6 7) (1 20 100) simpleGrading (1 0.4 1)
);
edges
(
);
boundary
(
top
{
type wall;
faces
(
(2 3 7 6)
);
}
bottom
{
type empty;
faces
(
(1 5 4 0)
);
}
frontedge
{
type wedge;
faces
(
(0 4 7 3)
);
}
backwedge
{
type wedge;
faces
(
(1 2 6 5)
);
}
inlet
{
type patch;
faces
(
(1 0 3 2)
);
}
outlet
{
type patch;
faces
(
(5 6 7 4)
);
}
);controldict file
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
application icoFoam;
startFrom startTime;
startTime 0;
stopAt endTime;
endTime 0.4;
deltaT 0.0004;
writeControl timeStep;
writeInterval 20;
purgewrite 0;
writeFormat ascii;
writePrecision 6;
writeCompression off;
timeFormat general;
timePrecision 6;
runTimeModifiable true;velocity boundary file
FoamFile
{
version 2.0;
format ascii;
class volVectorField
object U;
}
dimensions [0 1 -1 0 0 0 0];
internalField uniform(0.1869 0 0);
boundaryField
{
inlet
{
type fixedValue;
value uniform(0.1869 0 0)'
}
outlet
{
type symmetry;
}
frontwedge
{
type symmetry;
}
backwedge
{
type symmetry;
}
top
{
type noSlip;
}
bottom
{
type emmpty;
}
}pressure boundary file
FoamFile
{
version 2.0;
format ascii;
class volVectorField
object p;
}
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
inlet
{
type zeroGradient;
}
outlet
{
type fixedValue;
value uniform 0;
}
frontwedge
{
type symmetry;
}
backwedge
{
type symmetry;
}
top
{
type zeroGradient;
}
bottom
{
type emmpty;
}
}transport properties file
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object transportProperties;
}
nu [0 2 -1 0 0 0 0]0.001;Results tabulated for the wedge angle of 10 degrees
creating the mesh using grading factor 0.4 along with the height of the wedge for wedge angle 10 degrees
Results tabulated for wedge angle of 25 degress
creating the mesh using the grading factor 0.4 along with the height og the wedge for wedge angle 25 degrees
velocity profile
pressure profiel
velocity curve
fully developed velocity curve
shear stress curve
Results tabulated for wedge angle of 45 degrees
creating the mesh using the grading factor 0.4 along with the height og the wedge for wedge angle 45 degrees
velocity profile
pressure profiel
velocity curve
fully developed velocity curve
shear stress curve
