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

From Script | Spoken-Tutorial
Revision as of 11:56, 19 April 2013 by Nancyvarkey (Talk | contribs)

Jump to: navigation, search

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.
  • 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
  • ParaView version 3.12.0
Slide 4: Prerequisites To practice this tutorial learner should have the knowledge of

Basic Fluid Dynamics

and Hagen-Poiseuille flow

Slide 5:

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 fluid used, that is, water is given.

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

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

Slide 6:

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 mew 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 7: Transient Solver Type of solver used here is,

IcoFOAM


It is a Transient Solver

It is used for incompressible, laminar flow of Newtonian fluids.

Slide 8:

Pressure Boundary Conditions

Pressure Boundary Conditions used,

At Inlet: fixedPressure

At Outlet: fixedPressure

At Walls: ZeroGradient

Slide 9:

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 'icoFoam' folder.

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 the '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 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 velocity boundary condition is as shown:
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 10: 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 the z direction.
Point out the numbering pattern. Numbering Pattern is as shown.
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'.

Final blockMeshDict file is as shown:

Close the file and come out of the folder 'constant' Let's close the file and come out of the 'constant' folder.
Open and show transportProperties file and point at the value viscosity value We see the 'transportProperties' file.

Note the dynamic viscosity value, here, is 1e-06.

Close the file and come out of the 'constant' folder. Let's close the file and come out to the 'constant' folder.
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 time step has been set to 1e-03.

The solution converges after 18 seconds. The final time step is kept 19.

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' keys, 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 can see the iterations 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.

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 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 and press Apply.
Open the color legent Let's open the color legend.
We can see the maximum velocity is near to the actual maximum velocity.
Go to Filters> Data Analysis> Plot Over Lines To view the graph Go to Filters> Data Analysis> Plot Over Lines.
click on Y axis and press Apply Let's click on Y axis and press Apply.
Point towards the parabolic profile We see the parabolic profile for Hagen-Poiseuille flow.
Close the graph Let's close the graph.
Close ParaView Close ParaView.
Switch to the slides Let's switch to the slides.
Slide 11: Summary In this tutorial we have learned:
  • To create 3D pipe geometry.
  • To simulate Hagen-Poiseuille flow for a fixed pressure ratio.
  • To visualize the velocity results in ParaView.

This brings us to the end of the tutorial.

Slide 12 : Assignment


As an assignment,

Change the geometry parameters such as length and diameter.

Change the corresponding pressure ratio.

Use the fluid of different viscosity.

Slide 13: About Spoken tutorials
  • Watch the video available at the following link
  • It summarises the Spoken Tutorial project
  • If you do not have good bandwidth, you can download and watch it
Slide 14: About Spoken tutorials The Spoken Tutorial Project Team
  • Conducts workshops using spoken tutorials
  • Gives certificates for those who pass an online test
  • For more details, please write to contact at spoken hyphen tutorial dot org
Slide 15: Acknowledgement Spoken Tutorial Project is a part of the Talk to a Teacher project
  • It is supported by the National Mission on Education through ICT, MHRD, Government of India
  • More information on this Mission is available at
  • spoken hyphen tutorial dot org slash NMEICT hyphen Intro

Contributors and Content Editors

DeepaVedartham, Nancyvarkey, P12575, Sneha