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

Can Fluent find natural frequency?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 28, 2007, 08:08
Default Can Fluent find natural frequency?
  #1
Ken
Guest
 
Posts: n/a
Hi,

I have created a cicular cross section in GAMBIT to model a cylinderical structure and had exported the mesh file to FLUENT. I am trying to determine the natural frequency of the cylinder in FLUENT? Do you know any command in FLUENT that can determine the natural frequency, either both in air or water?

Thanks KWong
  Reply With Quote

Old   May 2, 2007, 13:56
Default Re: Can Fluent find natural frequency?
  #2
Will
Guest
 
Posts: n/a
You don't need Fluent to do this. If your Reynolds number is between 2000<Re<200000 then you can just assume a Strouhal number of 0.2 and go from there.
  Reply With Quote

Old   May 3, 2007, 03:56
Default Re: Can Fluent find natural frequency?
  #3
Ken
Guest
 
Posts: n/a
If i do not need FLUENT to do this, then what do i use??

Thanks
  Reply With Quote

Old   May 3, 2007, 14:12
Default Re: Can Fluent find natural frequency?
  #4
Will
Guest
 
Posts: n/a
For a cylinder in crossflow the Strouhal number, S = fD/U, (f = frequency, D = cylinder diamter, U = mean flow velocity) is pretty much constant for Reynolds numbers from 2000-200000. Just solve for the frequency.
  Reply With Quote

Old   September 23, 2014, 14:53
Default natural frequency
  #5
New Member
 
saeed
Join Date: Apr 2012
Posts: 9
Rep Power: 5
saeedjack is on a distinguished road
i modeled an external flow with fluent 6.1, how i can find natural frequency of it? if its possible or not?
and what is exactly output of acoustic model in fluent?
saeedjack is offline   Reply With Quote

Old   September 23, 2014, 20:40
Default
  #6
Member
 
Join Date: Dec 2009
Location: China
Posts: 79
Rep Power: 7
ringtail is on a distinguished road
Quote:
Originally Posted by saeedjack View Post
i modeled an external flow with fluent 6.1, how i can find natural frequency of it? if its possible or not?
and what is exactly output of acoustic model in fluent?
First, start the unsteady simulation of the flow until the flow become stable. I mean the vortex shedding become regular. Then monitor the lift of the cylinder for some time. After that, Do FFT to the lift data, and you will get a peak frequency. Generally, it is the natural frequence.
ringtail is offline   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
If I know one cell in the fluent ,how to find some other neigbor cell of it . wwt650420 FLUENT 0 March 23, 2011 12:12
Fluent 6.3.26 vs 12.1 and partition method Anorky FLUENT 0 April 27, 2010 10:55
Natural convection in Fluent Tanveer Main CFD Forum 4 May 20, 2008 12:31
Please help: - To find torque in Fluent.......... Jayanth FLUENT 0 December 31, 2007 04:40
where to find old version Fluent tutorial guid Roger FLUENT 0 March 11, 2002 18:04


All times are GMT -4. The time now is 03:56.