BlogFor BusinessTalk to a counsellor
CoursesIIT ProgramsPlacementsLog in
BlogFor Business
Talk to a counsellor
Challenge

Week 11 - Simulation of Flow through a pipe in OpenFoam

PPratyush Ranjan Meher16 Jan 2022
CFDMATLAB

Objective:- Calculation of flow variables using MATLAB for automation of inputs in blockMeshDict using wedge BCs and post processing it

Hagen Poiseuuile's Equation:

`DeltaP=(32muLv)/(d^2)`

where, `DeltaP`is the pressure drop along a cylindrical pipe for a incompressible and Newtonian Fluid

Assumptions:

  • Geomtery=Axi-symmetric
  • Reynolds number Re= 2100
  • Density=997 kg/m^3
  • Temperature= `25^0 C`
  • Dia of pipe = 0.02m
  • Dynamic Viscosity=0.089e-3 Pa.s
  • Kinematic Viscosity=0.8927e-6 `m^2/s`
  • theta=`4^0`

MATLAB Code for automatic input of blockMeshDict file in Open Foam :-

close all
clc

theta=4;
Re=2100;
D=0.02;
L=0.06*Re*D;
R=D/2;
mu=0.89e-3;
rho=997.0;
nu=mu/rho;

v_avg=Re*mu/(D*rho);
v_max=2*v_avg;
del_p=(32*mu*v_avg*L)/(D^2);
kin_P=del_p/rho;

n1=50;
n2=1;
n3=300;
gfactor=0.5;

v0=[0 0 0];
v1=[0 R*cosd(theta/2) -R*sind(theta/2)];
v2=[0 R*cosd(theta/2) R*sind(theta/2)];
v3=[L 0 0];
v4=[L R*cosd(theta/2) -R*sind(theta/2)];
v5=[L R*cosd(theta/2) R*cosd(theta/2)];

h1='/*--------------------------------*- C++ -*----------------------------------*\';
h2='  =========                 |';
h3=' \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox';
h4='  \\    /   O peration     | Website:  https://openfoam.org';
h5='    \\  /    A nd           | Version:  9';
h6='     \\/     M anipulation  |';
h7='\*---------------------------------------------------------------------------*/';
h8='FoamFile';
h9='{';
h10='    format      ascii;';
h11='    class       dictionary;';
h12='    object      blockMeshDict;';
h13='}';
h14='// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //';
h15='//***************************************************************************//';
f1=fopen('blockMeshDict.txt','w');

fprintf(f1,'%s \n',h1);
fprintf(f1,'%s \n',h2);
fprintf(f1,'%s \n',h3);
fprintf(f1,'%s \n',h4);
fprintf(f1,'%s \n',h5);
fprintf(f1,'%s \n',h6);
fprintf(f1,'%s \n',h7);
fprintf(f1,'%s \n',h8);
fprintf(f1,'%s \n',h9);
fprintf(f1,'%s \n',h10);
fprintf(f1,'%s \n',h11);
fprintf(f1,'%s \n',h12);
fprintf(f1,'%s \n',h13);
fprintf(f1,'%s \n',h14);
fprintf(f1,'\n');

fprintf(f1,'%s \n','convertToMeters 1;');
fprintf(f1,'\n');

fprintf(f1,'%s \n','vertices');
fprintf(f1,'%s \n','(');
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v0(1),v0(2),v0(3));
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v1(1),v1(2),v1(3));
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v2(1),v2(2),v2(3));
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v3(1),v3(2),v3(3));
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v4(1),v4(2),v4(3));
fprintf(f1,'\t %s (%f %f %f) \n', blanks(5),v5(1),v5(2),v5(3));
fprintf(f1,'%s \n',');');
fprintf(f1,'\n');

fprintf(f1,'%s \n','blocks');
fprintf(f1,'%s \n','(');
fprintf(f1,'%s %s \n',blanks(5),'hex(0 1 2 0 3 4 5 3) (50 1 200) simpleGrading(0.5 1 1)');
fprintf(f1,'%s \n',');');
fprintf(f1,'\n');

fprintf(f1,'%s \n','edges');
fprintf(f1,'%s \n','(');
fprintf(f1,'%s arc 1 2 (%f %f %f) \n',blanks(5),0,R,0);
fprintf(f1,'%s arc 1 2 (%f %f %f) \n',blanks(5),L,R,0);
fprintf(f1,'%s \n',');');
fprintf(f1,'\n');

fprintf(f1,'%s \n','boundary');
fprintf(f1,'%s \n','(');
fprintf(f1,'%s %s \n',blanks(5),'inlet');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type patch');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(0 1 2 0)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');

fprintf(f1,'%s %s \n',blanks(5),'outlet');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type patch');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(3 4 5 3)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');

fprintf(f1,'%s %s \n',blanks(5),'front');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type wedge');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(0 3 5 2)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');

fprintf(f1,'%s %s \n',blanks(5),'back');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type wedge');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(0 1 4 3)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');

fprintf(f1,'%s %s \n',blanks(5),'pipe');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type wall');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(1 4 5 2)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');

fprintf(f1,'%s %s \n',blanks(5),'axis');
fprintf(f1,'%s %s \n',blanks(5),'{');
fprintf(f1,'%s %s \n',blanks(10),'type empty');
fprintf(f1,'%s %s \n',blanks(10),'faces');
fprintf(f1,'%s %s \n',blanks(10),'(');
fprintf(f1,'%s %s \n',blanks(15),'(0 3 3 0)');
fprintf(f1,'%s %s \n',blanks(10),');');
fprintf(f1,'%s %s \n',blanks(5),'}');
fprintf(f1,'%s \n',');');
fprintf(f1,'\n');

fprintf(f1,'%s \n','mergePatchPairs');

fprintf(f1,'%s \n','(');
fprintf(f1,'%s \n',');');

fprintf(f1,'\n');

fprintf(f1,'%s \n',h15);
fclose(f1);

blockMeshDict file created using MATLAB Code:-

/*--------------------------------*- 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 
( 
	       (0.000000 0.000000 0.000000) 
	       (0.000000 0.009994 -0.000349) 
	       (0.000000 0.009994 0.000349) 
	       (2.520000 0.000000 0.000000) 
	       (2.520000 0.009994 -0.000349) 
	       (2.520000 0.009994 0.009994) 
); 

blocks 
( 
      hex(0 1 2 0 3 4 5 3) (50 1 200) simpleGrading(0.5 1 1) 
); 

edges 
( 
      arc 1 2 (0.000000 0.010000 0.000000) 
      arc 1 2 (2.520000 0.010000 0.000000) 
); 

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

mergePatchPairs 
( 
); 

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

controlDict file after setting endTime=10 and deltaT=0.001:-

/*--------------------------------*- 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         10;

deltaT          0.001;

writeControl    timeStep;

writeInterval   20;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

Pressure file after modifying the outlet Pressure and giving necessary condition to other parameters:-

/*--------------------------------*- 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
{
    pipe
    {
        type            zeroGradient;
    }

     
    inlet
    {
        type            zeroGradient;
    }

    outlet
    {
        type            fixedValue;
        value           uniform 0.0168682;
    }

    axis
    {
        type            empty;
    }
    
    front
    {
        type            wedge;
    } 
    
    back
    {
        type            wedge;
    }
    
}

Velocity file after modifying the inlet velocity and giving necessary condition to other parameters:-

/*--------------------------------*- 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 (0.0937312 0 0);
    }

    outlet
    {
        type            zeroGradient;
    }

    pipe
    {
        type            noSlip;
    }
    
    axis
    {
        type            empty;
    }
    
    front
    {
        type            wedge;
    } 
    
    back
    {
        type            wedge;
    }
    
    
}

transportProperties file after modifying nu value:-

/*--------------------------------*- 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] 8.927e-07;


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

Geometry Mesh created using paraFoam command:-

Velocity Contour:-

Velocity Profiles at different locations:

Velocity Profile at 0.02m from inlet

Velocity at 0.5m from inlet

Velocity profile at 2.52m from inlet

Conclusion:-

  • The stream is flat near the entrance region due to boundary layer effect.
  • As the fluid moves along the flow it starts changing its characteritics along the flow.
  • This results in the more parabolic flow chracteritics along the flow which termed as developed flow along the pipe
  • We can approximately say that the flow started becoming developed aroud 1.5m from the entry of pipe.
Your portfolio, next

Ship work like this
in your own course.

Talk to a career counsellor

Free 20-minute call. We'll map the right course to where you want to work.

By submitting you agree to our Terms and Privacy Policy.

Talk to a career counsellor

Free 20-minute call. We'll map the right course to where you want to work.

By submitting you agree to our Terms and Privacy Policy.