OpenFOAM/C3/Simulating-Hagen-Poiseuille-flow/English

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Tutorial: To simulate Hagen-Poiseuille flow in OpenFOAM.

Script and Narration : Saurabh S. Sawant

Keywords: Video tutorial,CFD.


Visual Cue Narration
Slide 1: Hello and welcome to the spoken tutorial on simulating Hagen-Poiseuille flow in OpenFOAM
Slide 2 : Learning Objectives


In this tutorial we will see:
  • To create and mesh 3D cylindrical pipe
  • To simulate the Hagen-Poiseuille flow
    having fixed pressure ratio across boundaries
    and
  • To visualize the velocity contour in ParaView
Slide 3: System Requirement To record this tutorial, I am using
  • Linux Operating system Ubuntu 12.04
  • OpenFOAM version 2.1.1 and
  • ParaView version 3.12.0
Slide 4: System Requirement

The tutorials were recorded using the versions specified in previous slide

Subsequently the tutorials were edited to latest versions

To install latest system requirements go to Installation Sheet

Slide 5: Prerequisites To practice this tutorial learner should have the knowledge of

Basic Fluid Dynamics

and Hagen-Poiseuille flow

Slide 6:

Hagen-Poiseuille Flow Diagram


Read aloud the given points and show the contents in the diagram with the mouse pointer.

Here is, Hagen-Poiseuille Flow Diagram

We can see the dimensions and boundaries of the pipe

Viscosity of the fluid used, that is, water is given

Pressure at the inlet is 20 Pascals and at the outlet it is 0 Pascals

As it is an incompressible flow, only the pressure difference is of importance

Slide 7:

Formulas and Analytical Solution

Read aloud the given points

Formulas and Analytical Solution:

For Hagen-Poiseuille flow,

Pressure drop along the pipe is:

(P1 minus P2) equals (32 mu Uaverage L) upon (D square)

By substituting the values from the previous diagram, we get,

Uaverage equals to 0.208 m/s

Maximum Velocity is given as,

Two times the average velocity, which would be, 0.416 m/s

Reynolds Number for the flow is,

Uaverage into D upon nu, that comes out to be, 2080

Hence, the flow is transient

Slide 8: Solver Type of solver used here is,

icoFOAM


It is a Transient Solver

It is used for incompressible, laminar flow of Newtonian fluid

Slide 9:

Pressure Boundary Conditions

Pressure Boundary Conditions used,

At Inlet: fixedPressure

At Outlet: fixedPressure

At Walls: ZeroGradient

Slide 10:

Velocity Boundary Conditions

Velocity Boundary Conditions used,

At Inlet: pressureInletVelocity

At Outlet: zeroGradient

At Walls: fixedValue

Show 3dpipe folder.

Show the 3dpipe folder

For executing this case,

First, Let's create the case directory in the 'icoFoam' folder

And Give it some name

I have named it as '3dpipe'

Point the mouse pointer from lid driven folder to 3d pipe folder. To know the location of this folder, go through the tutorial on lid driven cavity

Copy this '0' (zero), 'constant' and 'system' folders of lid driven cavity problem in the newly created folder.



Go inside the 3dpipe folder. Let's go inside the '3dpipe' folder
Hover the pointer over the folder inside the 3dpipe folder. I have already copied the folders into my '3dpipe' folder and modified the files in it
Go into the '0' folder and open P file and show it Now, let's go into the '0' folder

And open the 'P' file

This is the pressure boundary condition file

Show the pressure boundary condition file and show the dimensions inside it. Note that the dimensions are in (meter square) per (second square) (m2/s2)
Show the pressure value written Hence the pressure value in pascals is divided by the density, that is, 1000 Kg/m3 (Kg per meter cube), and written here.
Close the file Let's close the file
Open U file in the same folder and show File containing the velocity boundary condition is as seen:lets open the file we can see the velocity boundary condition for inlet, outlet and fixed walls
Close the file and come out of the '0' folder Let's close the file and come out of the '0' folder
Switch back to the slides To see the blocking strategy, let me switch back to the slides
Slide 11: Blocking Strategy

Hover the pointer on the geometry and drag it towards the z direction.

To create a 3D geometry of a pipe I have made a 2D circular geometry and extruded the length in z direction
Point out the numbering pattern. Numbering Pattern is as shown. We can also see the dimension of the mesh
Minimize the slides To see the blockMeshDict file, let's minimize the slides
Go to folder 'constant' and then 'polyMesh' and open blockMeshDict file and show it. Let's go into the folder 'constant', and then 'polyMesh' lets open theblockMeshDict ' file. We can see the vertices, blocks,edges and boundaries for inlet, outlet and fixed walls
Close the file and come out of the folder 'polyMesh Let's close the file and lets come out of the 'polyMesh' folder
Open and show transportProperties file and point at the value viscosity value We see the 'transportProperties'file. Lets open the file

Note the dynamic viscosity value, here, is 1 into 10 raise to minus 6

Close the file and come out of the 'constant' folder. Let's close the file and come out of the 'folder 'constant
Go into the system folder and open the controlDict file. Show it. Let's go into the 'system' folder

Now, let's have a look at the 'controlDict' file

Show time step value The solution converges after 18 seconds therefore the final time step is kept 19.The time step has been set to 1 into 10 raise to minus 3


Close the file and the Home folder Let's close the file

Let's close the 'Home' folder

Press 'control', 'alt' and 't' keys altogether Now to execute the case, we will, first, go inside the '3dpipe' folder through terminal.Let's open the terminal by pressing 'control', 'alt' and 't' key, altogether
Type run and press Enter in the terminal. Type run and press Enter
Type cd (space) tutorials and press Enter Type cd (space) tutorials and press Enter
Type cd (space) incompressible and press Enter Type cd (space) incompressible and press Enter
Type cd (space) icoFoam and press Enter Type cd (space) icoFoam and press Enter
Type cd (space) 3dpipe and press Enter Type cd (space) 3dpipe and press Enter
Type blockMesh and press Enter Now to create the mesh, type blockMesh and press Enter

Meshing has been done

After the meshing is done, type icoFoam to start the iterations To start the iterations type icoFoam and press Enter

We see the iterations are running

After the iterations are done, type paraFoam for postprocessing the results and press Enter. Iterations has been done

After the iterations end type paraFoam for postprocessing the results and press Enter. It will open the" paraview". This is " paraview"

Click on Apply. Let's click on Apply on the left hand side of the Object inspector menu to see the geometry
Rotate the geometry by pressing the button of the mouse and move it in the required direction. Let's rotate the geometry for a better view
Click on the active variable control menu and select U in the drop-down menu Click on the active variable control menu and select U in the drop-down menu
Click on play button At the top, in VCR toolbar, click on Play button
Go to Object Inspector menu, go to Display, click on Rescale data range Go to Object Inspector menu, go to Display, click on Rescale to data range
go to the toolbar named common, click on Clips and press Apply To view the half section, go to the toolbar named common, click on Clips go to object inspector menu properties and press Apply. Lets Zoom in
Open the color legend Let's open the color legend
We can see the maximum velocity is near to the actual maximum velocitythat is 0.40 meters per second
Go to Filters> Data Analysis> Plot Over Lines To view the graph Go to Filtersat the top Data Analysisand press Plot Over Line
click on Y axis and press Apply Press Y axis and press Apply
Point towards the parabolic profile We can see the parabolic profile for Hagen-Poiseuille flow
Close the graph Let's close the graph
Close ParaView lets Close ParaView
Switch to the slides And switch to the slides
Slide 12: Summary In this tutorial we have learnt:
  • To create and mesh 3D pipe geometry
  • To simulate Hagen-Poiseuille flow for a fixed pressure ratioacross boundaries and
  • To visualize the velocity results in Parafoam


Slide 13 : Assignment


As an assignment,

Change the geometry parameters such as length and diameter

Change the corresponding pressure ratio and

Use the fluid of different viscosity

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Slide 20: Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project
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Contributors and Content Editors

DeepaVedartham, Nancyvarkey, P12575, Sneha