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

Fluent results: stagnation pressure greater ....

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 1, 2005, 09:11
Default Fluent results: stagnation pressure greater ....
  #1
Amit Shrestha
Guest
 
Posts: n/a
Hi,

I have 3d blade model but with no radial variation. The stagnation pressure at the stagnation point is always greater than the total pressure i specified at the pressure inlet boundary condition at the inlet. there is only one inlet and one exit.

has anyone else experienced this?

Amit
  Reply With Quote

Old   December 1, 2005, 09:52
Default Re: Fluent results: stagnation pressure greater ..
  #2
Salvatore
Guest
 
Posts: n/a
I have a friend who have the same problem, but only with the k-e ad k-o turbulence model. He haven't problem when he use the Spalart-Almaras turbulence model. He had noted that the problem with k-e and k-o decrease refining the mesh. I don't know why but I think that there are some problem of numerical nature. Sorry, but I can't tell you nothing more... Bye bye
  Reply With Quote

Old   December 1, 2005, 20:06
Default Re: Fluent results: stagnation pressure greater ..
  #3
zxaar
Guest
 
Posts: n/a
its related to pressure gradient, when you refine the mesh the problems due to pressure gradients start vanishing. I had bad time predicting Cp for a sphere until i started using mesh with yplus around1 and enhanced wall functions. Try refining mesh in the important areas.
  Reply With Quote

Old   December 2, 2005, 06:36
Default Re: Fluent results: stagnation pressure greater ..
  #4
TomK
Guest
 
Posts: n/a
well, i think it is the natue of standard k-eps model. it fails in stagnation areas. about k-o, I do not know, no experience.

did you try k-eps rng ?

thomas
  Reply With Quote

Old   December 2, 2005, 07:24
Default Re: Fluent results: stagnation pressure greater ..
  #5
zxaar
Guest
 
Posts: n/a
yaa its related to model also, i have tried almost every model fianlly settled wit LES.
  Reply With Quote

Old   December 8, 2005, 08:01
Default Re: Fluent results: stagnation pressure greater ..
  #6
Amit Shrestha
Guest
 
Posts: n/a
Thanks for sharing your experiences! Nice to know its not just me who is getting that..

my Area weighted average total pressure also increases downstream of Trailing edge, which is again physically impossible. I guess, its the same reason again.

I will try k-e rng and see what happens.. other than that, i guess i will just note that people all over the world are experiencing similar problems!

Amit
  Reply With Quote

Reply


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
"Pressure Inlet" Boundary Setup Wijaya FLUENT 15 May 18, 2016 10:08
wind tunnel results vs fluent pixie Main CFD Forum 1 August 20, 2009 08:02
Different kinds of pressure in FLUENT Mattia FLUENT 0 October 22, 2007 08:52
Neumann pressure BC and velocity field Antech Main CFD Forum 0 April 25, 2006 02:15
Fluent 5.2, UDF and Pressure BC's Alfonso Ferrandez FLUENT 0 May 4, 2000 07:02


All times are GMT -4. The time now is 20:22.