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

High aspect ratio mesh problem for flat plate boundary layer

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 13, 2012, 23:57
Default High aspect ratio mesh problem for flat plate boundary layer
  #1
Member
 
pooyan
Join Date: Nov 2011
Posts: 61
Rep Power: 4
sam1364 is on a distinguished road
Hi everyone,

I am trying to simlulate flat plate boundary layer problem in OpenFoam. the flow is turbulent (Re=5*10^6). I want to use k-epsilon model to solve the problem.
because I need to use wall function in this case, I need to have my first yPlus in the gird at a value greater than 11. So, because I need many points in the log layer region, I have used a very fine mesh right after the first point in my grid. this makes a very high aspect ratio between the first cells (y+=11) and the above cell (where fine mesh starts). as a result, the simulation will be stopped because the courant number goes high suddenly.

Do you have any suggestion how I can fix my problem?!

Thanks,
sam1364 is offline   Reply With Quote

Old   May 14, 2012, 02:32
Default
  #2
Member
 
Jan
Join Date: Dec 2009
Location: Berlin
Posts: 50
Rep Power: 8
SirWombat is on a distinguished road
Send a message via Skype™ to SirWombat
To better understand your problem, you migth wanna post an image of those cells. How did you create your mesh (ie snappyHexMesh). What about checkMesh, does ist give you an OK? Have you tried viewing your problematic cells in paraview? Are you using prism layers?
__________________
~~~_/)~~~
SirWombat is offline   Reply With Quote

Old   May 14, 2012, 15:54
Default
  #3
Member
 
pooyan
Join Date: Nov 2011
Posts: 61
Rep Power: 4
sam1364 is on a distinguished road
I have created the mesh using gambit. OpenFoam said ok to my mesh.

Besides, I have always doubted about my numerical schemes. I would be grateful if you could have a look at my files and give any suggestions that might be helpful for me in the future.
I have included both my pisoFoam and simpleFoam numerical schemes.
Attached Images
File Type: jpg mesh1.jpg (52.0 KB, 60 views)
Attached Files
File Type: zip system.zip (3.4 KB, 15 views)
sam1364 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
SnappyHexMesh for internal Flow vishwa OpenFOAM Native Meshers: snappyHexMesh and Others 23 August 6, 2014 03:50
No layers in a small gap bobburnquist OpenFOAM Native Meshers: snappyHexMesh and Others 2 November 25, 2012 08:54
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 04:05
Turbulent boundary layer on a flat plate seb62 OpenFOAM Running, Solving & CFD 1 January 17, 2009 03:30
mesh for a high aspect ratio geometry matthias CFX 3 October 20, 2006 02:55


All times are GMT -4. The time now is 09:37.