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

HELP TIME on FLUENT

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 12, 2012, 18:26
Default HELP TIME on FLUENT
  #1
New Member
 
slim
Join Date: Apr 2012
Posts: 18
Rep Power: 13
slimmsk is on a distinguished road
hello,

I simulated a fluid flow in a straight pipe with ANSYS Fluent :

Inlet velocity : 0.116 m/s
Outlet pressure 400 Pa with mass flow rate 0.063 kg/s

Time step size: 60 seconds
Number of time step: 5
Number of iterations / time step: 300

I find the same result
I noticed that the solver resolves five blocks of 300 iterations each time, is it recalculates every time?

60 seconds is enough or must I fix a few minutes

thank you very much
slimmsk is offline   Reply With Quote

Old   May 12, 2012, 19:37
Default
  #2
Senior Member
 
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,649
Rep Power: 65
LuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura about
Quote:
Originally Posted by slimmsk View Post
hello,

I simulated a fluid flow in a straight pipe with ANSYS Fluent :

Inlet velocity : 0.116 m/s
Outlet pressure 400 Pa with mass flow rate 0.063 kg/s

Time step size: 60 seconds
Number of time step: 5
Number of iterations / time step: 300

I find the same result
I noticed that the solver resolves five blocks of 300 iterations each time, is it recalculates every time?

60 seconds is enough or must I fix a few minutes

thank you very much
it will solve 300 iterations at the current time, then move to the next time-step and do another 300 iterations until 5 time-steps have been solved.

isn't this a steady problem? none of your boundary conditions appear to be transient, your simulation will be steady even if you run a transient simulation.
LuckyTran is offline   Reply With Quote

Old   May 13, 2012, 06:04
Default
  #3
New Member
 
slim
Join Date: Apr 2012
Posts: 18
Rep Power: 13
slimmsk is on a distinguished road
hello,

I try to simulate flow between two cylinders.

Normally I should get a constant velocity profile along the length (figure 1).
Fig 1.gif
But, I found an acceleration along the entire length of the cylinder (figure 2).
Fig 2.gif
Change speed / length axis> 0

normally it must be = 0

I can not find the trick. Is that it's normal?

thank you
slimmsk is offline   Reply With Quote

Reply

Tags
cfd, flow, fluent, pipe flow, time

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
High Courant Number @ icoFoam Artex85 OpenFOAM Running, Solving & CFD 11 February 16, 2017 14:40
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
Time Scale in Fluent Andrew FLUENT 0 April 20, 2009 02:24
AMG versus ICCG msrinath80 OpenFOAM Running, Solving & CFD 2 November 7, 2006 16:15
Time Step Size for Airfoil Model - Fluent Prateek Main CFD Forum 0 November 4, 2004 19:42


All times are GMT -4. The time now is 02:35.