OpenFOAM/C2/2D-Laminar-Flow-in-a-channel/English - Revision history

Nancyvarkey at 02:14, 13 June 2019

2019-06-13T02:14:48Z

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DeepaVedartham at 06:04, 30 May 2019

2019-05-30T06:04:49Z

DeepaVedartham at 06:03, 30 May 2019

2019-05-30T06:03:20Z

DeepaVedartham at 06:02, 30 May 2019

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DeepaVedartham at 09:35, 11 April 2019

2019-04-11T09:35:46Z

Rahuljoshi at 10:56, 7 March 2013

2013-03-07T10:56:23Z

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Rahuljoshi at 06:30, 27 February 2013

2013-02-27T06:30:11Z

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Pravin1389 at 10:23, 20 February 2013

2013-02-20T10:23:11Z

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Rahuljoshi: Created page with 'Tutorial: Simulating Laminar flow in a channel. Script and Narration : Rahul Joshi Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel. {| style="border-spacing:…'

2013-02-20T10:11:25Z

Created page with 'Tutorial: Simulating Laminar flow in a channel. Script and Narration : Rahul Joshi Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel. {| style="border-spacing:…'

New page

Tutorial: Simulating Laminar flow in a channel.

Script and Narration : Rahul Joshi

Keywords: Video tutorial,CFD,laminar flow,simpleFoam,channel.

{| style="border-spacing:0;"
| style="border-top:0.05pt solid #000000;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| <center>Visual Cue</center>
| style="border:0.05pt solid #000000;padding:0.097cm;"| <center>Narration</center>

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Hello and welcome to the spoken tutorial on Simulating Laminar Flow in a Channel using openfoam

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 2 : Learning Objectives
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this tutorial I will show you

2D geometry of channel and initial boundary conditions

Meshing the Geometry

Solving and Post Processing results in Paraview

Validation with analytic result.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 3:

System Requirement
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To record this tutorial

I am using GNU / Linux Operating system Ubuntu 10.04 .

OpenFOAM version 2.1.0

ParaView version 3.12.0

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 4: Prerequisite
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You should know how to create geometry using OpenFOAM

If not, please refer to the relevant tutorials on the Spoken Tutorial website

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5 : About channel flow
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We simulate flow in a pipe so as to determine the flow development length along the downstream

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 6 : Diagram
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The boundary names and inlet flow is shown in this figure

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 :
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The flow develpoment length is given by the formula

L= 0.05 * Re * D

The pipe is of length 5 m and height 1 m.

Inlet velocity is 1 m/s.

Reynolds number ( Re ) is 100.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Solver: simpleFoam
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is a steady state problem

Therefore we are using a steady state incompressible solver for this case

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo:

SimpleFoam in incompressible flows
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We need to create a folder for our case.

The folders should be created inside the solver type you choose.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo

Create a floder and name it as channel in simpleFoam folder

copy 0,constant and system from pitzDaily to this channel folder

| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| I have already created a folder in simpleFoam folder of incompressible flow solvers

The folder is named as channel

Copy 0,Constant and System folders of any other case file in simpleFoam

Here i have copied the file structure of case of pitzDaily

Paste it in the channel folder created and make the necessary changes in the geometry,boundary faces and boundary condition

We will now see the file structure

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Press Ctrl+Alt+t keys simultaneously

Type in command terminal

run and press enter

tutorial and press enter

incompresible and press enter

simpleFoam and press enter

channel and press enter

ls and press enter
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Open a command terminal by pressing Ctrl+Alt +t keys simultaneously on your keyboard.

In the command terminal type the path for channel case

Type '''run and press enter'''

type '''tutorials and press enter'''

type '''incompressible and press enter'''

type '''simpleFoam and press enter'''

type '''channel and press enter'''

now type '''ls and press enter'''

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Type in command terminal

cd constant and press enter

ls and press enter

polymesh folder and 2 other files

gedit RASProperties and press enter

gedit transportProperties and press enter

In terminal type

cd polyMesh and press enter

in terminal type:

gedit blockMeshDict and press enter
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this you will see three folders '''0 , Constant and System'''

type cd '''constant and press enter'''

type '''ls and press enter'''

in this you will see files containing properties of fluid and a folder named polymesh

RASProperties containes Reynolds-averaged stress model

transportProperties contains transport model and

value of kinematic viscosity (nu) set at 0.001 m²/s.

Now type '''cd polyMesh and press enter'''

This contains the file blockMeshDict

To open the blockMeshDict file in the terminal '''type gedit blockMeshDict and press enter'''

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Refer to earlier tutorial for creating simple geometry in OpenFOAM

in terminal cd space .. twice and press enter

In terminal type:

cd space 0 and press enter

type ls and press enter
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To set up the blockMeshDict file refer to the tutorial for creating simple Geometry in OpenFOAM.

The geomery is in meters so the convertTometers is set to 1

next we have defined the vertices of the pipe

we have used a 40 X 40 mesh size here and cell spacing of

( 1 1 1 )

next we have the boundary conditions and their types which are set as '''inlet ,outlet,top,bottom '''

Since it is a 2D problem frontAndBack is kept empty.

We have entered here the type of boundary and their faces

Arcs and mergePatch pair is kept empty.

Close the blockMeshDict file

Type cd ..(dot dot and press enter after each) twice to go back to the channel folder

Now type '''cd 0 (Time directory) and press enter'''

Type''' ls and press enter'''

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In the terminal you can see the files

Slide 7 : formula to calculate epsilon and k.

Do not chnge the values of nu,nuTilde and R

Change only the boundary names

in terminal type : cd .. and press enter

System folder is kept default
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This contains the intial boundary conditions and wall functions for the channel case

It should contain various files named epsilon ,k, nu ,nuTilda which are the wall functions and

p , R and U are initial conditions of the flow

Calculate epsilon and k from the formula given in the

figure and enter it in the file.

Change only the boundary names in each of the above folder.

Note that the values in nu,nuTilde and R are to kept default

Changes are only made in boundary condition names.

Rest of the files should contain initial value for each of the boundary faces.

Now Type '''cd (space) ..(dot dot) and press enter'''

There is no change in the system folder

We need to mesh the geometry

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In terminal type:blockMesh and press enter
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the command terminal '''type blockMesh and press enter'''

Meshing is done

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 7 :simpleFoam
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The type of solver we are using here is simpleFoam

It is a Steady-state solver for incompressible, turbulent flow

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Type simpleFoam and press enter

| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In the command terminal '''type simpleFoam and Press enter'''

Iterations running will be seen in the terminal.

The iterations will stop once the solution is converged or it reaches end time value.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| In terminal

type: paraFoam and press enter
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| To view the results in paraview in the terminal

type '''paraFoam and press enter'''

This will open up the paraviw window

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo

Solid color to U

initial state at inlet boundary

click on the play button

final contour of velocity

toggle color legend on from left hand side top
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| On let hand side of the paraview window click Apply

The geometry can be seen here.

In top of active variable control menu change the drop down menu from solid color to capital U.

You can see the initial state of velocity magnitude at inlet.

On top of the paraview window click on the play button of VCR control menu

you can see the final value of velocity magnitude.

Also toggle on the color legend from left hand side top of active variable control menu.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Demo
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| We can see that once the flow has fully devloped it attains a maximum uniform velocity at center.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 8:Validation
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The results obtained can be validated with the analytical solution for laminar flow in a pipe which is u(max)=1.5 Uavg

Using openfoam we obatain a velocity of 1.48 m/s which is a good match.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 9 : Summary
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| In this tutorial we learnt

File structure of channel

Obtained solution using steady state solver

Viewed the geometry in paraview

Validation with analytic results

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 10 :

Assignment

| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As an assignment:

Solve the problem for Reynold Number 1500 and validate it with the analytical result

this brings us to the end of the tutorial

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 11 :

| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The video available at this URL:

http://spoken-tutorial.org/What_is_a_Spoken_Tutorial

It summarizes the Spoken Tutorial project.

If you do not have good bandwidth, you can download and watch it.

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 12 :

About Spoken tutorials
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| The Spoken Tutorial Project Team

-Conducts workshops using spoken tutorials

-Gives certificates to those who pass an online test

-For more details, please write to contact@spoken-tutorial.org

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 13

Acknowledgement

| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Spoken Tutorials are part of Talk to a Teacher project,

It is supported by the National Mission on Education through ICT, MHRD, Government of India.

This project is coordinated by http://spoken-tutorial

More information on the same is available at the following URL link http://spoken-tutorial.org/NMEICT-Intro

|-
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 14:

About the contributor
| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| This is Rahul Joshi from IIT BOMBAY signing off.

Thanks for joining.

|}

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 |-
-| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5 : Pre-requisite
+| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 5 : Prerequisite
-| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| You should know how to create '''geometry''' using '''OpenFOAM '''
+| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| As a Prerequisite for this tutorial, You should know how to create '''geometry''' using '''OpenFOAM '''

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 |-
 | style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:none;padding:0.097cm;"| Slide 1
-| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Hello and welcome to the spoken tutorial on '''Simulating Laminar Flow in a Channel using openfoam'''
+| style="border-top:none;border-bottom:0.05pt solid #000000;border-left:0.05pt solid #000000;border-right:0.05pt solid #000000;padding:0.097cm;"| Hello and welcome to the spoken tutorial on '''Simulating 2D Laminar Flow in a Channel using openfoam'''
 |-

@@ Line 51: / Line 51: @@
 Hence forth all the tutorials will be covered using '''OpenFOAM version 2.1.1''' and''' ubuntu version 12.04'''
 |-
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 -For more details, please write to [mailto:contact@spoken-tutorial.org contact@spoken-tutorial.org]