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

Timestep

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 11, 2006, 08:47
Default Timestep
  #1
Joe
Guest
 
Posts: n/a
Hi

When running a simulation and fails at a specific timestep can this be interpeted at the length of the domain which has got stuck?

I mean if i have a domain of 10m and velocity 1m/s, physical time 10s. Inputting a physical timescale of 0.5s and the simulation fails at timestep 5, does it mean that it was at 2.5m when it was running?

I am running a steady state simulation and usually fails at 8,9,10 timestep and when i reduce the timescale it can go maximum to 17.

Thanks in Advance.
  Reply With Quote

Old   August 11, 2006, 09:04
Default Re: Timestep
  #2
Mike
Guest
 
Posts: n/a
Hi Joe, failing at a particular timestep cannot be interpreted in this way. Your best bet is to look at the results before it fails and see what the flow is doing. The solver diagnostics in the out file should also provide some clues - e.g. which equations were struggling, was the solver stable before it failed. Mike
  Reply With Quote

Old   August 11, 2006, 09:26
Default Re: Timestep
  #3
alex
Guest
 
Posts: n/a
HI joe, i had the same problem and, as said mike look at which equations were struggling. My issue was solved by changing turbulence model. ALex
  Reply With Quote

Old   August 12, 2006, 06:28
Default Re: Timestep
  #4
Ravi
Guest
 
Posts: n/a
I want information for Time step
  Reply With Quote

Old   August 23, 2006, 07:51
Default Re: Timestep
  #5
Houman
Guest
 
Posts: n/a
Hi, as Mike has written, you can not judge the results for the error runs like that... as far as it's about Time step settings, you better take a look at the CFX manual :

ANSYS CFX-Solver, Release 10.0: Modelling | Advice on Flow Modelling | Timestep Selection |

there you'll find some good general information about Timesteps, but your problem can also be because of something else, so don't ristrict your view to "timesteps" but it can be because of one of the boundary conditions or ...

best regards, Houman
  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
Restart 2-way FSI with different timestep? Lance CFX 10 April 17, 2013 01:37
Timestep study ijk CFX 6 April 9, 2010 08:38
interTrackFoam timestep virginie_e OpenFOAM Running, Solving & CFD 4 April 6, 2009 06:02
Use of Timestep in obtaining solution. hagupta CFX 7 February 28, 2006 14:14
Timestep selection Jindra Kosprdova CFX 9 April 28, 2005 07:41


All times are GMT -4. The time now is 18:48.