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

Do I need PRESTO!?, Body force weighted or ??

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 30, 2007, 00:38
Default Do I need PRESTO!?, Body force weighted or ??
  #1
jrg
Guest
 
Posts: n/a
Hi. I have a jet hitting a wall before leaving the outlet located at one end of the wall. Between the impingement point and the outlet, there are some swirls. Flow is incompressible and laminar.

In this case, should one apply a more elaborate pressure discretization scheme? I used the standard scheme and the outlet pressure is off by 20% compared to expt data. When I tried PRESTO!, solution diverges.
  Reply With Quote

Old   September 30, 2007, 19:38
Default Re: Do I need PRESTO!?, Body force weighted or ??
  #2
jrg
Guest
 
Posts: n/a
To elaborate further, I also use the SIMPLEC. When in combination with PRESTO and with skewness correction of 1 or more, solution diverges. Without skewness correction, convergence can be achieved.

The question now is if skewness correction is necessary? Does it change the solution or does it affects only convergence speed?. The mesh is an unstructured hex.

If I use body force weighted, I can get a stable solution even with some skewness correction.

Can someone make sense out of these observations?
  Reply With Quote

Old   August 31, 2012, 11:33
Default PRESTO! or BFW ??
  #3
Senior Member
 
Bionico's Avatar
 
Flavio
Join Date: Sep 2011
Location: Brescia, Italy
Posts: 181
Rep Power: 15
Bionico is on a distinguished road
Hi everybody,
I'm modeling a heat source in a closed room. My mesh is quite dense: 4M tetra (around the source) and 4k Hexa (far from the source).
Can anybody tell me which discretization method for pressure is better? PRESTO! o BODY FORCE WEIGHTED? What are the differences between them?

Thanks in advance
__________________
Bionico

Last edited by Bionico; September 3, 2012 at 08:36.
Bionico is offline   Reply With Quote

Old   September 3, 2012, 08:38
Default
  #4
Senior Member
 
Bionico's Avatar
 
Flavio
Join Date: Sep 2011
Location: Brescia, Italy
Posts: 181
Rep Power: 15
Bionico is on a distinguished road
I read something about the presence of corners: for this reason PRESTO! should be better. Can anyone confirm it?
__________________
Bionico
Bionico is offline   Reply With Quote

Old   January 22, 2018, 08:32
Default
  #5
Senior Member
 
Yuehan
Join Date: Nov 2012
Posts: 142
Rep Power: 13
wc34071209 is on a distinguished road
Have you found the answers? I asked a similar question but have not received help yet.
wc34071209 is offline   Reply With Quote

Reply

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
Force can not converge colopolo CFX 13 October 4, 2011 23:03
gravity terms & Body Force Weighted meshkati Main CFD Forum 0 January 4, 2010 05:06
Body force at the cell face Souviktor Fluent UDF and Scheme Programming 0 March 31, 2009 09:54
Body Force weighted Sanxian Main CFD Forum 0 June 15, 2007 09:21
UDF for lift force on a bluff body sawa FLUENT 2 April 11, 2005 04:06


All times are GMT -4. The time now is 00:26.