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

transient pressure correction

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 21, 2004, 13:47
Default transient pressure correction
  #1
dominique
Guest
 
Posts: n/a
hi,

i'm doing pseudo-compressibility pressure correction in transient low R_e flow in a tube (2D). how do I choose optimal ratio between dt for velocity update and (pseudo) dt for pressure correction? in particular: is it better to do more velocity corrections and few pressure corrections or vice versa?

thank you.
  Reply With Quote

Old   April 22, 2004, 08:51
Default Re: transient pressure correction
  #2
vesi
Guest
 
Posts: n/a
If you are using pseudo-compressibility method, then pressure is also updated via time or pseudo time marching, then you do the same times of corrections to both V and P.
  Reply With Quote

Old   April 22, 2004, 18:03
Default Re: transient pressure correction
  #3
dominique
Guest
 
Posts: n/a
you mean, correct velocity, correct pressure and again, in a loop? yes, that is clear, but what about "dt", how do I set optimal relation between two delta t's for both explicit time marching...?

thanks domi
  Reply With Quote

Old   April 23, 2004, 06:29
Default Re: transient pressure correction
  #4
versi
Guest
 
Posts: n/a
Years Ago AIAA Journal had papers discussing pseudo time sep and physical time step. The pseuodtime step has the meaning of relaxation factor, it can be larger than a nondimensional physical Dt. may be 10 times up, I remebered. If the inner iteration is implicit can be 10^12 up. (== discarding it at all)
  Reply With Quote

Old   April 23, 2004, 12:14
Default Re: transient pressure correction
  #5
centaur_ks
Guest
 
Posts: n/a
read paper on dual time step approch , try one by Yoon and Jameson on LU-SSOR for eular and NS eqn and there are some more by Jameson that explains dual time stepping approch quite well.
  Reply With Quote

Old   May 27, 2004, 09:03
Default Harlow & Amsden
  #6
enis
Guest
 
Posts: n/a
Hello everyone,

Is there anybody who are using IMF(Implicit Multifield Model of Harlow & Amsden) technique for their studies?I want to ask some questions.

thanks
  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
Pressure correction equation,Ferziger and Peric Hooman Main CFD Forum 1 July 20, 2010 06:21
Pressure correction on SIMPLE Diego Nogueira Main CFD Forum 6 October 10, 2004 15:43
Transient pressure in conduit John Main CFD Forum 0 October 28, 2003 18:26
Pressure correction question - Please help! Barry Main CFD Forum 1 February 5, 2003 01:27
what the result is negatif pressure at inlet chong chee nan FLUENT 0 December 29, 2001 06:13


All times are GMT -4. The time now is 09:55.