CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > FLOW-3D

pressure iteration didnt converge

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By melek

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 25, 2013, 20:41
Default pressure iteration didnt converge
  #1
New Member
 
melek
Join Date: Aug 2013
Posts: 27
Rep Power: 12
melek is on a distinguished road
how can I edit this error? what is that mean?

Solver Messages: pressure iteration did not converge in itmax= 100 iterations
at time= 1.03537E-02 cycle= 90 iter= 100 nocon= 0
epsi= 4.083E-01 maximum residual= 5.539E-01 at i= 124 j= 2 k= 70 block= 5
convective flux exceeded stability limit
at t= 3.2759E-02 cycle= 306 iter= 5 delt= 3.4220E-05 mesh block 5
restarting cycle with smaller time step
maximum failure ratio = 2.95606E+00 is in z-coordinate direction
at cell ( 233, 2, 215) mesh block 5
Attached Files
File Type: txt warning error.txt (23.7 KB, 45 views)

Last edited by melek; December 26, 2013 at 06:36.
melek is offline   Reply With Quote

Old   December 30, 2013, 03:30
Default
  #2
New Member
 
Mohammadreza
Join Date: Nov 2013
Posts: 11
Rep Power: 12
mo.sharifabadi is on a distinguished road
Dear Melek
The solver, solve 100 times an iteration, if the stop criteria accepted then go to next iteration, but if it unaccepted so stop the solving. So, no way to get the accurate simulation results.

Regards,
M. R. sharifabadi
mo.sharifabadi is offline   Reply With Quote

Old   January 11, 2014, 12:49
Default
  #3
New Member
 
melek
Join Date: Aug 2013
Posts: 27
Rep Power: 12
melek is on a distinguished road
Thank you Sharifabadi. so do you have any idea how can I correct the mistake... I tried to increase GMPRES number and decrease messh sell sizes. However the simulation runned with 2 gb and again took this message. pressure iteration didnt converse itmax =100
melek is offline   Reply With Quote

Old   January 12, 2014, 04:07
Default
  #4
New Member
 
Mohammadreza
Join Date: Nov 2013
Posts: 11
Rep Power: 12
mo.sharifabadi is on a distinguished road
As far as I know, there is no way to take away from this problems, restart your simulation from first ( call STL files ) and do simulation again may you haven't problem.

Don't hesitate if you have any question.
this is my email address: mo.sharifabadi@gmail.com
mo.sharifabadi is offline   Reply With Quote

Old   March 7, 2014, 01:50
Default
  #5
New Member
 
Join Date: Feb 2014
Posts: 8
Rep Power: 12
johnsonw is on a distinguished road
Have you corrected you problem? i am stuck in such a situaiton too
johnsonw is offline   Reply With Quote

Old   March 26, 2014, 10:13
Default
  #6
New Member
 
Maxime
Join Date: Mar 2014
Posts: 16
Rep Power: 12
macsim is on a distinguished road
Do you have different mesh blocks in your model ?

It can be due to connection problems between mesh blocks (or bad cell size ratio).
macsim is offline   Reply With Quote

Old   March 26, 2014, 20:59
Default
  #7
New Member
 
Join Date: Feb 2014
Posts: 8
Rep Power: 12
johnsonw is on a distinguished road
Quote:
Originally Posted by macsim View Post
Do you have different mesh blocks in your model ?

It can be due to connection problems between mesh blocks (or bad cell size ratio).
I didn't add any mesh plane to the mesh block,just let mesh generator do the job.
johnsonw is offline   Reply With Quote

Old   March 27, 2014, 06:09
Default
  #8
New Member
 
Maxime
Join Date: Mar 2014
Posts: 16
Rep Power: 12
macsim is on a distinguished road
If you have thin thickness, it could be interesting to add mesh planes.

Usually, a list of messages as your comes from bad mesh conditions. When you analyze results, geometry visualization is good ?
macsim is offline   Reply With Quote

Old   March 28, 2014, 10:15
Default
  #9
New Member
 
melek
Join Date: Aug 2013
Posts: 27
Rep Power: 12
melek is on a distinguished road
Thank you for answers, mesh and geo was crossed I thınk but only I wrote relaxatıon factor = 0,5 and downed tıme step all problems are over
nauman maldar likes this.
melek is offline   Reply With Quote

Old   March 28, 2014, 10:18
Exclamation
  #10
New Member
 
melek
Join Date: Aug 2013
Posts: 27
Rep Power: 12
melek is on a distinguished road
And mesh was strong I thınk chanced mesh desıgn
melek is offline   Reply With Quote

Old   March 28, 2014, 10:24
Default n
  #11
New Member
 
melek
Join Date: Aug 2013
Posts: 27
Rep Power: 12
melek is on a distinguished road
thank you for answers
melek is offline   Reply With Quote

Old   September 18, 2019, 21:15
Default
  #12
Member
 
NR
Join Date: Aug 2019
Posts: 30
Rep Power: 6
nauman maldar is on a distinguished road
Hey melek ...can u please tell me in detail what exactly did u do to overcome that problem..because i am facing the same problem for days now? Please help..
nauman maldar is offline   Reply With Quote

Old   October 5, 2019, 17:37
Default
  #13
Member
 
Ysmn
Join Date: Mar 2018
Location: Auburn,AL
Posts: 34
Rep Power: 8
elyasmin is on a distinguished road
Hi Nauman,

Could you find the solution?

Thanks,
Yasemin
elyasmin is offline   Reply With Quote

Old   November 19, 2019, 11:40
Default
  #14
Senior Member
 
thunde47
Join Date: Dec 2015
Location: India, USA
Posts: 129
Blog Entries: 1
Rep Power: 10
thunde47 is on a distinguished road
Quote:
Originally Posted by melek View Post
how can I edit this error? what is that mean?

Solver Messages: pressure iteration did not converge in itmax= 100 iterations
at time= 1.03537E-02 cycle= 90 iter= 100 nocon= 0
epsi= 4.083E-01 maximum residual= 5.539E-01 at i= 124 j= 2 k= 70 block= 5
convective flux exceeded stability limit
at t= 3.2759E-02 cycle= 306 iter= 5 delt= 3.4220E-05 mesh block 5
restarting cycle with smaller time step
maximum failure ratio = 2.95606E+00 is in z-coordinate direction
at cell ( 233, 2, 215) mesh block 5
Also, try using a much smaller initial time-step.
thunde47 is offline   Reply With Quote

Old   November 21, 2019, 21:42
Default
  #15
Member
 
NR
Join Date: Aug 2019
Posts: 30
Rep Power: 6
nauman maldar is on a distinguished road
Yes Yasmin, all i needed to do was create two mesh blocks seperately for the geometry and the bigger domain.. and also need to take care that the boundaries of the smaller mesh block cells coincide with the boundaries of the bigger mesh block cells...
nauman maldar is offline   Reply With Quote

Old   December 18, 2019, 02:10
Default
  #16
Member
 
Ysmn
Join Date: Mar 2018
Location: Auburn,AL
Posts: 34
Rep Power: 8
elyasmin is on a distinguished road
Thank you!
elyasmin is offline   Reply With Quote

Old   December 18, 2019, 02:12
Default Cfd
  #17
Member
 
NR
Join Date: Aug 2019
Posts: 30
Rep Power: 6
nauman maldar is on a distinguished road
Quote:
Originally Posted by elyasmin View Post
Hi Nauman,

Could you find the solution?

Thanks,
Yasemin
You are welcome
nauman maldar 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
lid-driven cavity in matlab using BiCGStab Don456 Main CFD Forum 1 January 19, 2012 15:00
Setup/monitor points of pressure and force coefficients siw CFX 3 October 22, 2010 06:07
Operating condition in Fluent MASOUD FLUENT 3 September 16, 2010 17:50
Neumann pressure BC and velocity field Antech Main CFD Forum 0 April 25, 2006 02:15


All times are GMT -4. The time now is 08:04.