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

Total time recommended for a DES

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 31, 2013, 07:05
Default Total time recommended for a DES
  #1
siw
Senior Member
 
Stuart
Join Date: Jul 2009
Location: Portsmouth, England
Posts: 470
Rep Power: 14
siw will become famous soon enough
Hi,

I'm setting up a DES of the flow over a bluff body. Firstly, I have run steady RANS which is the starting condition of the DES. I have run three DES cases for 50 iterations each and at different timesteps to see which one would give CFL numbers below 1 (via Fluent's histogram). The largest timestep to achieved that was 1x10-5s.

Now I can set up the full simulation. But I'm unsure of the total time needed. If I estimate the residence time for a fluid element to pass through the domain at the freestream speed then that time is 0.08s. Let's say I let the simulation run for three times that duration (0.24s), then that would be 24,000 timepoints at the timestep of 1x10-5s.

Is that sensible? What have others done? Because it'll take along time to do this. Can a running average of important output data be set in Fluent?

Thanks
siw is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to determine time step size and Max. iterations per time step. pratik c FLUENT 38 February 11, 2015 07:44
Sudden jump in Courant number NJG OpenFOAM Running, Solving & CFD 7 May 15, 2014 13:52
Unstabil Simulation with chtMultiRegionFoam mbay101 OpenFOAM Running, Solving & CFD 13 December 28, 2013 14:12
plot over time fferroni OpenFOAM Post-Processing 7 June 8, 2012 07:56
Total time for simulation Meerkat Main CFD Forum 1 September 5, 2011 07:17


All times are GMT -4. The time now is 02:57.