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

Transient 3D calulations

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 17, 2000, 05:18
Default Transient 3D calulations
  #1
G. Berntsen
Guest
 
Posts: n/a
Hi everyone.

I'm trying to do a cavitation calculation in a hydroturbine impeller using FLUENT5. This means that I have to use the transient solver. Test calculations, with the cavitation model activated, resulted in extremely unphysical results. This lead me to try the transient solver without the cavitation model invoked. This also resulted in strange solutions.

The way I have done this is by first calculating a steady-state solution (which seems to be a correct solution), and then starting the transient solver. The impeller movement is set up with the moving reference frame model.

Am I missing an option in FLUENT somewhere, or is it just impossible to do this kind of calculation?

Has anyone got any experience with this kind of problem? I would be very grateful for any recommandations concerning boundary conditions, discretization schemes, number of iterations pr. time step etc.

Thanks.

G. Berntsen.
  Reply With Quote

Old   February 24, 2000, 10:20
Default Re: Transient 3D calulations
  #2
Kuochen Tsai
Guest
 
Posts: n/a
Rotational reference frame is meaningful for steady-state solutions.
  Reply With Quote

Old   February 24, 2000, 10:41
Default Re: Transient 3D calulations
  #3
Jonas Larsson
Guest
 
Posts: n/a
Eh, it is also meaningful for transient simulations... Rotating cavities is a typical example.
  Reply With Quote

Old   February 24, 2000, 10:47
Default Re: Transient 3D calulations
  #4
Kuochen Tsai
Guest
 
Posts: n/a
Yes, for rotating cavity it is OK, but not for impellers or solid boundaries with relative boundary movment.
  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
Transient conduction possible in fluent? jlefevre76 FLUENT 2 February 5, 2013 10:53
Laminar gas flow under slight suction - transient works but not steady audrey CFX 1 September 8, 2011 19:43
Best practice for transient simulations? siw CFX 5 October 30, 2010 05:45
transient simulation of a rotating rectangle icesniffer CFX 1 August 8, 2009 07:25
Transient vs Steady State Adam CFX 1 April 12, 2007 11:34


All times are GMT -4. The time now is 03:24.