CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

the continuity residual is not converging

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 17, 2017, 23:23
Default the continuity residual is not converging
  #1
New Member
 
Cakov
Join Date: Mar 2017
Posts: 5
Rep Power: 9
Cakov is on a distinguished road
file:///C:/05_AS002BEME5/mecca/mecca02_files/dp0/FLU/Fluent/SYS.2-5-00248.jpg

i am simulating a car park with jet fans. both inlet and outlet of the fans are labeled with fans(boundary condition). the pressure jump at the outlet is 700Pa.
a steady state, standard k-e turbulence, pressure-velocity is coupled.

how to reduce the continuity residuals? pls help me!
Cakov is offline   Reply With Quote

Old   March 18, 2017, 05:25
Default
  #2
Senior Member
 
Behrooz Jamshidi
Join Date: Apr 2013
Posts: 110
Rep Power: 13
CFD-fellow is on a distinguished road
Hi
If your setup is correct then try increasing your mesh density in high gradient regions.
CFD-fellow is offline   Reply With Quote

Old   March 19, 2017, 04:02
Default
  #3
Member
 
Join Date: May 2016
Posts: 38
Rep Power: 9
GregCFD is on a distinguished road
What's your mesh quality like?, I've generally found that continuity is particularly sensitive to the quality of the mesh and won't converge when the other quantities will.

p.s.

With images I find it's best to upload then to a storage website, like Imgur, first and then link them here. I don't think you can directly upload to to here (anymore?).
GregCFD is offline   Reply With Quote

Old   March 19, 2017, 05:53
Default
  #4
New Member
 
Cakov
Join Date: Mar 2017
Posts: 5
Rep Power: 9
Cakov is on a distinguished road
Quote:
Originally Posted by CFD-fellow View Post
Hi
If your setup is correct then try increasing your mesh density in high gradient regions.
i am not very sure about the setup. most of it i just leave it at default.
But i did increase the number of mesh but the continuity residuals is still at 10^-2
Cakov is offline   Reply With Quote

Old   March 19, 2017, 06:02
Default
  #5
New Member
 
Cakov
Join Date: Mar 2017
Posts: 5
Rep Power: 9
Cakov is on a distinguished road
Quote:
Originally Posted by GregCFD View Post
What's your mesh quality like?, I've generally found that continuity is particularly sensitive to the quality of the mesh and won't converge when the other quantities will.

p.s.

With images I find it's best to upload then to a storage website, like Imgur, first and then link them here. I don't think you can directly upload to to here (anymore?).
My mesh size function is proximity.
Relevance center is fine.
Smoothing is high
Transition is Fast
Span angle center is fine

The rest is set as default.
Cakov is offline   Reply With Quote

Old   July 20, 2017, 16:15
Default
  #6
New Member
 
yardena jodeck
Join Date: May 2017
Posts: 29
Rep Power: 9
BlackHeartInertia is on a distinguished road
I have the same problem. I decided to accept that value and and use more convergence criteria.

Maybe someone here that knows more than us can say if this is ok or not

Sent from my SM-G570M using CFD Online Forum mobile app
BlackHeartInertia is offline   Reply With Quote

Reply

Tags
continuity residual, fluent, jet fan


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
pimpleDyMFoam computation randomly stops babapeti OpenFOAM Running, Solving & CFD 5 January 24, 2018 05:28
simpleFoam error - "Floating point exception" mbcx4jc2 OpenFOAM Running, Solving & CFD 12 August 4, 2015 02:20
Micro Scale Pore, icoFoam gooya_kabir OpenFOAM Running, Solving & CFD 2 November 2, 2013 13:58
calculation stops after few time steps sivakumar OpenFOAM Running, Solving & CFD 7 March 17, 2013 06:37
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 18:07


All times are GMT -4. The time now is 07:29.