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

Static pressure-adaptation gradient

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 30, 2001, 06:45
Default Static pressure-adaptation gradient
  #1
Andrew Parker
Guest
 
Posts: n/a
Hi

Does any body know when you should stop adapting the static pressure gradient in your model? I know that the refine value that should be entered should typically be about 1/10th of the computed value, but when should you stop this process. For example if I am using the two-layer zonal method I know that I have to continue adapting until the y+ value is below 4 or 5-what is the similar value of the static pressure gradient.

Thanks

Andy
  Reply With Quote

Old   August 30, 2001, 09:28
Default Re: Static pressure-adaptation gradient
  #2
Philipp
Guest
 
Posts: n/a
this might sound a bit stupid, but I think you should stop when you reached a result that is in regard on accuracy versus CPU time OK for you. If you cannot say what is a good result cause you have nothing to compare with, than I would suggest to go forward and forward until the changes of the result are getting smaller and smaller. Of course it's you again who has to decide when the changes are small enough... Do you already tried different mesh types (e.g. compare structured and unstructured models with each other) or different models (laminar, k-e, ... whatever fits more or less to your problem)?

best regards philipp
  Reply With Quote

Old   September 3, 2001, 00:04
Default Re: Static pressure-adaptation gradient
  #3
Nurul Murad
Guest
 
Posts: n/a
hi..from my limited experience...usually you will do grid independency when you refine your grid...ie. in pressure gradient. if you refine double the original grid size everytime and the solution doesn't change much (usually 5% and below is good enough)...then you can confidently say that it is time to stop refining. from my experience...you will need a large grid size by doing grid independcy using k-e turb model as oppose tu LES. LES will require about half of what k-e usually acquire. please check on this..thanks..
  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 averaging at the outlets. KM CFX 6 April 1, 2021 06:28
defining a term for a domain using DEFINE_ADJUST MASOUD Fluent UDF and Scheme Programming 1 September 24, 2010 05:08
How to achieve constant static pressure in inlet? Zou Jianfeng FLUENT 0 October 21, 2008 01:55
pressure gradient term in low speed flow Atit Koonsrisuk Main CFD Forum 2 January 10, 2002 10:52
Static vs Total Pressure Alfonso Ferrandez FLUENT 2 May 23, 2000 08:53


All times are GMT -4. The time now is 19:57.