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

the initial condition for transient simulation

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

Like Tree1Likes
  • 1 Post By pavitran

Reply
 
LinkBack Thread Tools Display Modes
Old   August 21, 2012, 22:33
Wink the initial condition for transient simulation
  #1
New Member
 
su yunde
Join Date: Aug 2012
Location: China
Posts: 11
Rep Power: 5
junc is on a distinguished road
hi, everyone.
i am modeling a ducted fan in cfx. And i'd like to run a transient analysis using the steady state simulation as an initial guess. however, it's very hard to reach convergence in the steady state simulation, and the RMS Residual Level of velocity is about 2.2*10^-4.
Can i use this steady condition as the initial guess for the transient simulation?
thanks, any help would be appreciated!
junc is offline   Reply With Quote

Old   August 21, 2012, 22:57
Default Hi
  #2
Member
 
Dynampally Pavitran
Join Date: Mar 2010
Location: India
Posts: 73
Rep Power: 7
pavitran is on a distinguished road
Check for the mass and momentum imbalances, if they are ok then you can use the result as initial conditon for transient simulation. You can have an additional check by monitoring some integral quantity like torque.

If the problem which your simulating is inherently transient in nature, then the residuals would be oscillating and achieving convergence criteria would be difficult.

All the best
junc likes this.
pavitran is offline   Reply With Quote

Old   August 22, 2012, 06:13
Default
  #3
New Member
 
su yunde
Join Date: Aug 2012
Location: China
Posts: 11
Rep Power: 5
junc is on a distinguished road
thank you for your reply, i will check that.
junc is offline   Reply With Quote

Reply

Tags
initial conditions, transient simulation

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
transsonic nozzle with rhoSimpleFoam Unseen OpenFOAM Running, Solving & CFD 7 April 16, 2014 03:38
SLTS+rhoPisoFoam: what is rDeltaT??? nileshjrane OpenFOAM Running, Solving & CFD 4 February 25, 2013 05:13
alphaEqn.H in twoPhaseEulerFoam cheng1988sjtu OpenFOAM Bugs 14 September 18, 2011 13:46
Orifice Plate with a fully developed flow - Problems with convergence jonmec OpenFOAM Running, Solving & CFD 3 July 28, 2011 05:24
MRFSimpleFOAM goes divergenced! renyun0511 OpenFOAM Running, Solving & CFD 0 November 19, 2009 03:11


All times are GMT -4. The time now is 08:06.