CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Programming & Development

Surface tracking in interfoam

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   January 1, 2011, 09:34
Default Surface tracking in interfoam
  #1
New Member
 
Join Date: Sep 2009
Posts: 15
Rep Power: 0
Mjoelnir is on a distinguished road
Hi everyone,

i need to track to interface in interFoam. this is my current attempt:

Code:
    forAll(mesh.cells(), celli)
{
    if ((alpha1[celli] >= scalar(0.01))&&(alpha1[celli] <= scalar(0.99))) 
    {
        T[celli] = scalar(200);

        
    }

        
}
Where T is the Temperature but i use it to mark the cells that i have found.

the problem with that is that the interface in interfoam isn't 100% sharp. It is a bit diffuse. So i track sometimes double the cells. Simply right alpha == 0.5 doesn't work. The programm now finds the cells that have the alpha value of 0.5, but a cell can be a surface cell with a value of 0.01 to 0.99.
In paraFoam simply typing alpha 0.5 is working fine. Does anyone know what the name of the function is to find the surface. It is finding the right surace cells.

Best regards

Henning
Mjoelnir is offline   Reply With Quote

Old   January 3, 2011, 11:56
Default
  #2
Assistant Moderator
 
Bernhard Gschaider
Join Date: Mar 2009
Posts: 3,915
Rep Power: 40
gschaider will become famous soon enoughgschaider will become famous soon enough
Quote:
Originally Posted by Mjoelnir View Post
Hi everyone,

i need to track to interface in interFoam. this is my current attempt:

Code:
    forAll(mesh.cells(), celli)
{
    if ((alpha1[celli] >= scalar(0.01))&&(alpha1[celli] <= scalar(0.99))) 
    {
        T[celli] = scalar(200);

        
    }

        
}
Where T is the Temperature but i use it to mark the cells that i have found.

the problem with that is that the interface in interfoam isn't 100% sharp. It is a bit diffuse. So i track sometimes double the cells. Simply right alpha == 0.5 doesn't work. The programm now finds the cells that have the alpha value of 0.5, but a cell can be a surface cell with a value of 0.01 to 0.99.
In paraFoam simply typing alpha 0.5 is working fine. Does anyone know what the name of the function is to find the surface. It is finding the right surace cells.

Best regards

Henning
What do you want to use the data for afterwards. If you just want to statically postprocess the results the sample-utilitiy with a isosurface (alpha==0.5) might be sufficient.

http://openfoamwiki.net/index.php/Contrib/swak4Foaman can now work for sampledSurfaces and example where this is used to track the height of a surface is
https://openfoam-extend.svn.sourcefo...capillaryRise/

But of course if you afterwards need the T-field to implement some physics that depend on the interface then this won't help you

Bernhard
gschaider is offline   Reply With Quote

Old   January 4, 2011, 10:53
Default
  #3
New Member
 
Join Date: Sep 2009
Posts: 15
Rep Power: 0
Mjoelnir is on a distinguished road
Does paraFoam use the sample surface to create the surface?

I want to implent some physics by this
Mjoelnir is offline   Reply With Quote

Old   January 5, 2011, 09:41
Default
  #4
Assistant Moderator
 
Bernhard Gschaider
Join Date: Mar 2009
Posts: 3,915
Rep Power: 40
gschaider will become famous soon enoughgschaider will become famous soon enough
Quote:
Originally Posted by Mjoelnir View Post
Does paraFoam use the sample surface to create the surface?

I want to implent some physics by this
If the sampled surface is written in VTK-format paraview can read them.

If you need the surface for physics, then swak won't help you. Maybe there is a way to easily find out which cells a sampledSurface passes through (but I'm not aware of it)
gschaider is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with Gmsh nishant_hull Open Source Meshers: Gmsh, Netgen, CGNS, ... 19 Yesterday 05:10
Error : Self intersecting surface mesh, computing intersections & Error : Impossible velan Open Source Meshers: Gmsh, Netgen, CGNS, ... 1 July 14, 2015 05:54
boundaries with gmshToFoam‏ ouafa Open Source Meshers: Gmsh, Netgen, CGNS, ... 7 May 21, 2010 12:43
Tensions on free surface interFoam sega OpenFOAM Running, Solving & CFD 0 April 29, 2008 14:26
CFX4.3 -build analysis form Chie Min CFX 5 July 12, 2001 23:19


All times are GMT -4. The time now is 02:10.