CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Strange non converging beharvior

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 18, 2014, 18:51
Default Strange non converging beharvior
  #1
Member
 
Gregoire Junqua
Join Date: Jun 2011
Location: China
Posts: 58
Blog Entries: 1
Rep Power: 14
gregjunqua is on a distinguished road
Hi all, I am using a k-omega SST with simpleFoam over a flat boundary.
I testing different inlet condition. For my first test I just use a log law.
But i am facing a non convergence of my simulation with Uy (vertical wind speed) residual after a nice decrease it increase to around 0.001.

I saw some topic speaking about it but they didn't gave the solution of this problem.

if you got any idea that i could try it would be helpful
Thanks
gregjunqua is offline   Reply With Quote

Old   August 19, 2014, 08:54
Default
  #2
Senior Member
 
RodriguezFatz's Avatar
 
Philipp
Join Date: Jun 2011
Location: Germany
Posts: 1,297
Rep Power: 26
RodriguezFatz will become famous soon enough
What boundary conditions do you have at the wall?
__________________
The skeleton ran out of shampoo in the shower.
RodriguezFatz is offline   Reply With Quote

Old   August 19, 2014, 09:30
Default
  #3
Member
 
Gregoire Junqua
Join Date: Jun 2011
Location: China
Posts: 58
Blog Entries: 1
Rep Power: 14
gregjunqua is on a distinguished road
Quote:
Originally Posted by RodriguezFatz View Post
What boundary conditions do you have at the wall?
for k i got the standard one how
for omega it is omegaWallFunction
for nut nutKAtmRoughWallFunction
U it is fixed to 0

do you think it come from there?

I fixed it by using a simple grading in blockMeshDict. But if somebody could explain why.
gregjunqua is offline   Reply With Quote

Old   August 19, 2014, 09:34
Default
  #4
Senior Member
 
RodriguezFatz's Avatar
 
Philipp
Join Date: Jun 2011
Location: Germany
Posts: 1,297
Rep Power: 26
RodriguezFatz will become famous soon enough
Quote:
Originally Posted by gregjunqua View Post
for k i got the standard one how
What does that mean?

What y+ do you have?
__________________
The skeleton ran out of shampoo in the shower.
RodriguezFatz is offline   Reply With Quote

Old   August 19, 2014, 20:03
Default
  #5
Member
 
Gregoire Junqua
Join Date: Jun 2011
Location: China
Posts: 58
Blog Entries: 1
Rep Power: 14
gregjunqua is on a distinguished road
Quote:
Originally Posted by RodriguezFatz View Post
What does that mean?
the zeroGradient one
for y+ I will have look later i am not in my work office
gregjunqua is offline   Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Strange Flamelet Generation Problem tar FLUENT 11 March 22, 2014 10:52
[swak4Foam] very strange behavior samiam1000 OpenFOAM Community Contributions 3 December 6, 2013 13:20
Strange residuals behaviour xxxx Main CFD Forum 1 July 13, 2013 14:40
Strange boundary behaviour using interFoam Andrea_85 OpenFOAM 11 January 22, 2013 15:09
A Strange Problem in making Parallel (Ansys/CFX 12) a.sarami CFX 13 October 7, 2010 01:33


All times are GMT -4. The time now is 16:32.