# Multiple steady state with same boundary conditions

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

 July 13, 2011, 04:45 Multiple steady state with same boundary conditions #1 Member   Faisal Durrani Join Date: Nov 2009 Location: England Posts: 62 Rep Power: 9 Sponsored Links Hello, I am looking at Natural ventilation inside buildings. I have read many papers where for the same geometry of the building they acquire multiple steady states of the final ventilation flow. Experimentally they observe such phenomena by repeating the experiment a couple of times. I am now using LES to simulate such multiple steady states. Can some one advice me how to acquire them using LES? I mean if I run LES once on a geometry I will get one steady state right? But how do I get the other steady states for the same boundary conditions? Thank you

 July 13, 2011, 09:08 #2 Senior Member   Join Date: Apr 2009 Posts: 532 Rep Power: 14 LES is always transient. To get the "steady state" result you could collect variable averages using transient statistics. Collecting the averages over sequential time periods would give multiple "steady state" results.

 July 13, 2011, 19:07 #3 Member   Faisal Durrani Join Date: Nov 2009 Location: England Posts: 62 Rep Power: 9 Thank you stumpy for your helpful reply. I am collecting transient averages of velocity, temp and pressure. When you said "collecting the averages of sequential time periods" what exactly did you mean. I mean I am running a simulation of lets say 0 to 100 sec. I will get transient averages in cfx-post for the full 0-100sec. Then what did you mean by "collecting the averages of sequential time periods"??? Thank you.

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post icemaniac178 CFX 1 March 30, 2011 19:11 Pankaj CFX 9 November 23, 2009 05:05 Lisa Main CFD Forum 11 July 5, 2000 14:37 Christian Redl Main CFD Forum 1 April 14, 2000 11:51 Jan Ramboer Main CFD Forum 11 August 16, 1999 08:59