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

LES : ERROR #004100018 (tried a few things)

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 5, 2008, 03:37
Default LES : ERROR #004100018 (tried a few things)
  #1
KK
Guest
 
Posts: n/a
Hi,

I get the following error while simulating single phase flow in a cyclone with LES model. The initial condition is a solution from RSM turbulent model which had reached steady state.

ERROR #004100018 has occurred in subroutine FINMES. Message: Fatal overflow in linear solver."

If I change my boundary conditions from OPENING to OUTLET, solution proceed and solver does not fail. (Though temporary walls are raised in almost 100% boundary area.)

I searched all the the possible threads in this forum related to this problem and also read the manual for advice on flow modeling (convergence)

My doubts are

1) Why does it fail with OPENING type of boundary conditions while OPENING has addition degree of freedom as compared with OUTLETS ?

2) I changed my time step from 0.0005 sec to adaptive time steping with maximum inner loop iterations to be 2 and maximum 5. Time step update takes place at every 6th time step. But it still FAILED after a while.

3) The same mesh worked well with RANS (SSG-RSM). I know LES needs finer and better quality mesh. Could my mesh still be responsible for solver failure?

I would highly appreciate any comments,

Thanks,KK.

  Reply With Quote

Old   February 5, 2008, 17:43
Default Re: LES : ERROR #004100018 (tried a few things)
  #2
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

I suspect your boundary is too close to the action so it is having problems converging. Have you tried moving your boundary further away?

Glenn Horrocks
  Reply With Quote

Old   February 5, 2008, 18:28
Default Re: LES : ERROR #004100018 (tried a few things)
  #3
KK
Guest
 
Posts: n/a
Hi Glenn,

I had already moved both the outlets (or openings, whatever) by 35 mm and 25 mm from cylindrical and conical regions, respectively. The total length of domain (before extending outlets) was 266 mm. Could you please suggest if I had extended by a sensible length ?

My geometry's image is posted at following link.

http://imgplace.com/image/view/44cd2...4897905ff1e80b

Thanks, KK
  Reply With Quote

Old   February 6, 2008, 17:25
Default Re: LES : ERROR #004100018 (tried a few things)
  #4
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

Looks too close to me. I would try extending them both by quite a lot further.

Glenn Horrocks
  Reply With Quote

Old   February 7, 2008, 17:35
Default Re: LES : ERROR #004100018 (tried a few things)
  #5
KK
Guest
 
Posts: n/a
Thank your very much Glenn. I shall implement the suggestion.

KK.
  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
LES basic and simple questions. dshawul Main CFD Forum 0 October 4, 2010 11:56
Turbulence dampening due to magnetic field in LES and RAS eelcovv OpenFOAM 0 June 8, 2010 12:35
LES and combustion model Margherita Cadorin CFX 0 October 29, 2008 06:24
LES on two phase flow Li Yang Main CFD Forum 0 May 12, 2004 09:10
Some Questions about LES. Bin Li Main CFD Forum 2 February 20, 2004 10:58


All times are GMT -4. The time now is 07:14.