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

Residuals not dropping in simpleFOAM.

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 26, 2018, 02:48
Default Residuals not dropping in simpleFOAM.
  #1
New Member
 
Manideep Reddy
Join Date: Aug 2017
Posts: 7
Rep Power: 8
Manideep Reddy is on a distinguished road
Dear Foamers,

I am trying to simulate external flow over a geometry of an airship using simpleFoam solver and found that the residuals are not dropping at all after few iterations. So, I stopped the solver to see the pressure field. I found that the flow is not symmetric and pressure drag is more than five time that expected. Can anyone please explain why is this happening..?
Is this because I am using steady state solver for flows with unsteady phenomenon involved or other reason.

Thanks in advance.


TThanks in advance.
Attached Images
File Type: jpg press_28.jpg (26.0 KB, 197 views)
File Type: jpg residuals.jpg (38.3 KB, 200 views)
Manideep Reddy is offline   Reply With Quote

Old   April 26, 2018, 03:09
Default
  #2
Senior Member
 
piu58's Avatar
 
Uwe Pilz
Join Date: Feb 2017
Location: Leipzig, Germany
Posts: 744
Rep Power: 15
piu58 is on a distinguished road
Depending on your Re number you may get an oscillatory solution. I recommend to use a transient solver like pimple- or pisoFoam. You see more directly where the problems of your models are.
__________________
Uwe Pilz
--
Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)
piu58 is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
SimpleFoam: High residuals after increase in Reynolds Number JasonG OpenFOAM Running, Solving & CFD 21 October 5, 2017 10:11
Buoyantboussinesq simpleFoam residuals problem Naresh yathuru OpenFOAM Running, Solving & CFD 6 March 20, 2015 14:33
simpleFoam parallel solver & Fluent polyhedral mesh Zlatko OpenFOAM Running, Solving & CFD 3 September 26, 2014 06:53
motorBike Residuals for SST k-omega... and mine JR22 OpenFOAM Running, Solving & CFD 6 August 1, 2013 09:08
SimpleFoam - Interpretation of Residuals despaired student OpenFOAM Running, Solving & CFD 3 February 8, 2013 07:39


All times are GMT -4. The time now is 11:45.