Difference between revisions of "OpenFOAM/C2/Creating-simple-geometry-in-OpenFOAM/English"

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 295: Line 295:
  
  
−
Enter the points for the blocks in a clockwise sense.
+
Enter the points for the blocks in the clockwise sense.
  
 +
We are using here hexahedral blocks for meshing.
  
−
in '''brackets''' enter '''( 0 put space after each point and enter 1 2 3 4 5 6 7 ) '''
+
Now type hex '''H E X''', leave some space, in brackets enter '''(0 space 1 space 2 space 3 space 4 space 5 space 6 space 7)'''. Again leave some space.
  
  
−
For '''multiple blocks''' the points will be more.  
+
 
 +
Note that for '''multiple blocks''' the points will be more.  
  
 
|-
 
|-
Line 311: Line 313:
  
 
enter ( 30 30 1)
 
enter ( 30 30 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;"| In '''brackets''' enter '''(30 space 30 space 1)''', you can '''modify''' the '''grid''' when needed.
+
| 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 '''brackets''' enter '''(30 space 30 space 1)''', leave some space. You can '''modify''' the '''grid''' when needed.
  
 
|-
 
|-

Revision as of 15:03, 29 May 2019

Title of script: Creating simple geometry in OpenFOAM

Author: Rahul Ashok Joshi

Keywords: Video Tutorial,Computational Fluid Dynamics (CFD),OpenFOAM geometry


Visual Cue
Narration
Slide 1 Hello and welcome to the spoken tutorial on creating a simple geometry in OpenFOAM
Slide 2: Learning Objective In this tutorial I will show you
  • How to create a simple geometry
  • How to view geometry in paraview
Slide 3: System Requirement To record this tutorial I am using
  • Linux Operating system Ubuntu 10.04
  • OpenFOAM version 2.1.0
  • 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.

Only narration


run>> tutorials >> incompressible>> icoFoam >>cavity

In CFD the Pre-processing part consists of creating geometry and meshing it.

Let us take the Lid driven cavity case as an example.

I have already opened the command terminal and entered

the path for lid driven cavity.

Slide 5: For OpenFOAM v 5.0 
To source the OpenFOAM version 5, type:

$of5

To go to the run folder, type:

$cd $FOAM_RUN

To open the cavity case directory, type:

$cd tutorials/incompressible/icoFoam/cavity/cavity

To list the contents of case directory, type:

$ls

In the command terminal


constant>>polyMesh

There are three folders 0,constant,and system

Geometry is inside the polymesh folder of constant.

Terminal window: type cd constant In the command terminal type cd constant and press Enter.
Type ls Now type ls and press Enter.


In this there is another folder called as polymesh.

Type cd polyMesh Type cd polymesh and press Enter.
Type ls Now type ls and press Enter.
Slide 6: For OpenFOAM v 5.0

To list the contents of the cavity directory, type:

$ls 0 constant system

To open the system directory, type:

$cd system

To list the contents of the system directory, type:

$ls blockMeshDict controlDict fvSchemes fvSolution

Open the blockMeshDict file.


Type gedit blockMeshDict

This contains the geometry file called as blockMeshDict.

Open the blockMeshDict file with any editor of your choice.

In the terminal type gedit blockMeshDict.

Note that M and D here are capital and press Enter.

Let me drag this to the capture area.

Now minimise this.

Slides Let me switch back to the slides.
Hover over the diagram In OpenFoam the entire geometry is broken into blocks.
Block vertex starts from 0 The blocks are numbered starting from 0 as shown in the figure.
For 2D geometry enter a unit thickness cell in z axis Note that in OpenFOAM for creating a 2D geometry, you need to give cell thickness value in the z-axis.
Dimension of Cavity Lid driven cavity is of length 1 and height 1.


Minimise the slide.

Create empty file

right click >create document>empty file

On your desktop create an empty file by


right click > create document > Empty file


Name this as blockMeshDict.

(Note that M and D here are capital)

Copy data from old blockMeshDict file


upto convertToMeters

Open this.

Now copy the data from the original lid driven cavity blockMeshDict file to the new blockMeshDict file from line 0.


Scroll up. line 0 upto convertTometers.

Copy this and paste it here.

Scroll down.

Now leave some space after convertTometers.

Enter 1 as the geometry is in meters.

Insert a semi-colon and press Enter.

Again press Enter.

In the blockMeshDict file


type vertices

In the file type vertices and press Enter.
Insert ( Insert the open bracket and press Enter.

Press the Tab key.

Start with point 0


(0 0 0) and move to positive x axis


enter (1 0 0)

Start with point 0.

Insert open close brackets.

Enter

(0 space 0 space 0) and press Enter.

Again press Tab key.

Open close bracket.


Move towards point 1 in positive x-axis and enter (1 space 0 space 0) and press Enter.

Point 2 in the x-y plane Again press the Tab key. Open close bracket.

Move towards point 2 in the positive x-y plane and enter (1 space 1 space 0)

Press Enter.

Point 3 in y direction Again press the Tab key. Open close bracket.

Enter the 3rd point in positive y axis (0 space 1 space 0 )

Press Enter.

Point 4 in the front face

enter (1 0 1)

Again press the Tab key.

Enter the 4th point on the front face.

Open close bracket. (0 space 0 space 0.1)

And press Enter.

Points 5,6,7 with unit cell thickness in z axis Similarly enter the other points with one unit value in the positive z -axis.
Inert ) and ; Close the bracket and insert a semicolon after it.

Press Enter.

Again press Enter.

Type blocks and insert (


Lid driven cavity is a single block

Below vertices are the blocks.

Type blocks and press Enter.

Insert an open bracket and press Enter.

Let me switch back to the slides.

Note that Lid driven cavity is taken as a single block

Enter the vertices of block


block (0 1 2 3 4 5 6 7 ) total 8 points

Let me switch back to blockMeshDict.


Enter the points for the blocks in the clockwise sense.

We are using here hexahedral blocks for meshing.

Now type hex H E X, leave some space, in brackets enter (0 space 1 space 2 space 3 space 4 space 5 space 6 space 7). Again leave some space.


Note that for multiple blocks the points will be more.

Enter grid points in x, y and z axis After this enter the grid points in the x,y,and z directions
Enter the mesh/grid size

enter ( 30 30 1)

In brackets enter (30 space 30 space 1), leave some space. You can modify the grid when needed.
Grid point in z axis is kept as 1 Grid point in z-axis can be kept as one
Enter simpleGrading value ( 1 1 1 )


insert ) and ;

Leave a space and in brackets enter the simple grading for the mesh (1 space 1 space 1)

Close the bracket and insert a semicolon and press enter



Type edges Now type edges,as this is a simple geometry edges can be kept empty
Insert ( ); Insert open and closed bracket ,put a semicolon and press enter
Boundary conditions Below edges are the boundary conditions.
Here you need to enter the boundary name for the faces
Type boundary


insert (

Type boundary and in the next line and press enter


insert a open bracket and press enter


Let me switch back to slides

Slide : Geometry In the geometry the upper wall is moving and other three walls are fixed.
Front and back faces are kept as empty The front and back faces are termed as empty as this is a 2D problem
Open the current blockMeshDict file Open the New blockMeshDict file again
Boundary patch as moving wall In boundary put the name of the patch as moving wall
Insert { Insert a open curly bracket
Type of moving wall : wall


insert ;

Enter type for the moving wall as wall and


insert a semicolon

Enter and type faces

Enter open and close brackets In brackets enter the points for faces

Let me switch to slides
Slide : Geometry Note that order the points in such a way that the thumb should be normal to that face
Clockwise curl of fingers And fingers make a clockwise curl as shown in the figure
Points should be entered matching the points inserted in vertices Also note that the points should match with the points inserted in vertices
Enter (3 7 6 2)


insert } and ;

Enter the face points as (3 space 7 space 6 space 2) as shown in the figure


Insert a curly brackets and put a semicolon.



Boundary patches for fixedWalls Similarly enter boundary condition and faces for the fixed wall
For front and back face enter type as empty Being a 2D problem the type of boundary


for front and back face can be kept empty

Insert Insert open-closed brackets and put a semicolon.
BlockMeshDict file is completed


We are done with creating the blockMeshDict file.

The complete blockMeshDict file is as shown here.

Close the original blockMeshDict file


The command terminal will not work till blockMeshDict is closed

Close the original blockMeshDict file


Note that command terminal will not work until blockMeshDict file is closed

Type cd .. twice type cd (dot) (dot) twice to return to the cavity folder Mesh the geometry
Meshing, type blockMesh in terminal type: blockMesh and press enter
Viewing the geometry type paraFoam View the geometry by typing in the command terminal paraFoam and press enter



In the object inspector menu click Apply On the left hand side click Apply on object inspector menu
Slide In this tutorial we learnt:

Creating a simple geometry in OpenFOAM

Viewed the geometry in Paraview

This brings us to the end of the tutorial

Slide : Assignment Assignment

Change the geometry parameters : Enter the grid points as (40 40 1) and (50 50 1).

View the geometry in paraview



Slide : About spoken tutorials Watch 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.

Slide : about spoken tutorials 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 us at contact@spoken-tutorial.org

Slide : Forum to answer questions Do you have questions on THIS Spoken Tutorial?

Choose the minute and second where you have the question Explain your question briefly Someone from the FOSSEE team will answer them. Please visit http://forums.spoken-tutorial.org/

Slide : Forum to answer questions Questions not related to the Spoken Tutorial?

Do you have general/technical questions on the Software? Please visit the FOSSEE forum http://forums.fossee.in/ Choose the Software and post your question

Slide : Lab Migration project We coordinate migration from commercial CFD software like ANSYS to OpenFOAM

We conduct free Workshops and provide solutions to CFD Problem Statements in OpenFOAM For more details visit this site: http://cfd.fossee.in/

Slide : Case Study project We invite students to solve a feasible CFD problem statement of reasonable complexity using OpenFOAM

We give honorarium and certificate to those who do this For more details visit this site: http://cfd.fossee.in/

Slide: Acknowledgement 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.

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

About the contributor This is Rahul Joshi from IIT BOMBAY signing off.

Thanks for joining.



Contributors and Content Editors

Chandrika, DeepaVedartham, Nancyvarkey, Rahuljoshi

Retrieved from "https://script.spoken-tutorial.org/index.php?title=OpenFOAM/C2/Creating-simple-geometry-in-OpenFOAM/English&oldid=47575"