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

Flow past a sphere

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 17, 2009, 17:10
Default
  #21
Member
 
Muhammed Asmail
Join Date: Nov 2009
Location: Iraq
Posts: 36
Rep Power: 7
Muhammed_iraq is on a distinguished road
Quote:
Originally Posted by thecfduser View Post
Hi
For the realtion between Re and Nu, i dont know it, but it is sure that u can find a lot of correlations in bibilography...
For the Strouhal number, it is not easy... U must monitor data in a point that is behind ure sphere, then give this data to Matlab and do a fast fourrier transform to get the frequency of ure eddies....Once u have this frequency, u can calculate the Stouhal number...I dont know if this number is affected by temperature in ure case...
Regards
dear Karine
please give me the options of fluent to reach strouhal number field
i am waiting your reply
regards
Muhammed_iraq is offline   Reply With Quote

Old   December 17, 2009, 18:47
Default
  #22
Senior Member
 
karine
Join Date: Nov 2009
Posts: 158
Rep Power: 7
thecfduser is on a distinguished road
Hi Muhammed
I dont know how to do it in Fluent
I do it on Matlab
In fluent, put a point behind ure sphere and monitor velocity in it. The data that u will get, u must treat it on Matlab with a fast fourrier transform to get the frequency of ure coherent structures. If ure Re is <120 (i think) u will not get any vortex schedding: u will get a toroidal vortex....


(there is no strouhal number field: there is ONE Strouhal number in ure flow)

Hope that i was clear
thecfduser is offline   Reply With Quote

Old   December 18, 2009, 04:00
Default
  #23
Member
 
Muhammed Asmail
Join Date: Nov 2009
Location: Iraq
Posts: 36
Rep Power: 7
Muhammed_iraq is on a distinguished road
Quote:
Originally Posted by thecfduser View Post
Hi Muhammed
I dont know how to do it in Fluent
I do it on Matlab
In fluent, put a point behind ure sphere and monitor velocity in it. The data that u will get, u must treat it on Matlab with a fast fourrier transform to get the frequency of ure coherent structures. If ure Re is <120 (i think) u will not get any vortex schedding: u will get a toroidal vortex....


(there is no strouhal number field: there is ONE Strouhal number in ure flow)

Hope that i was clear
Dear Karine
in the past and by chance and from options of fluent , i found the box contain Strouhal Number but i forget the option and help of my fluent not found in my computer,please can you find this option from your help of your fluent ,can you send example in the matlab in order to strouhal Number to my e-mail(muham76@yahoo.com)
i am waiting your reply
many thanks
Muhammed_iraq is offline   Reply With Quote

Old   December 18, 2009, 16:32
Default
  #24
Senior Member
 
karine
Join Date: Nov 2009
Posts: 158
Rep Power: 7
thecfduser is on a distinguished road
Hi
In fact, Fluent is able to do a FFT but i had ever tried it....it is bette anyway to do it on matlab ot mathematica...
for matlab i dont have it for instance to help u ...sorry...but if i rememeber good, the function name is FFT
hope that somebody can help u more
thecfduser 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
flow past a sphere CHEN Main CFD Forum 1 January 30, 2010 03:12
Supersonic flow past a wedge with counter flow Mahesh Bailakanavar FLUENT 0 February 14, 2008 01:21
results for flow past flat plate normal to flow lisa Main CFD Forum 2 August 30, 2005 16:36
flow past sphere: surface pressure distribution roland schmehl Main CFD Forum 3 August 21, 2001 13:29
boudary conditions for flow past a sphere srijit goswami Main CFD Forum 3 January 27, 2001 08:28


All times are GMT -4. The time now is 19:14.