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

Newbie Navier Stokes Questions + Grid

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 5, 2006, 13:11
Default Newbie Navier Stokes Questions + Grid
  #1
Jigar
Guest
 
Posts: n/a
hello

if i am running Navier Stokes for the entire 3d flow domain (near wall and far from walls), is the y+ value really an issue in this case?

Is doing a simple grid dependecy check enough for near wall regions???? (my problem is flow in a room so no Eulerian at is used at all)

my 2nd question:

if i use Power (Watts) as boundary conditions instead of Surface temperature for an object, is it true that the grid distribution near the object is not really important???

  Reply With Quote

Old   February 6, 2006, 10:01
Default Re: Newbie Navier Stokes Questions + Grid
  #2
ag
Guest
 
Posts: n/a
Your questions are not really independent. Grid resolution is important if you want to resolve the gradients that control the flow. If you don't care about the gradients then use whatever grid you want. If the velocity gradient near the wall (which is actually fairly important in most flows) is not an issue then y+ is unimportant. And regardless of what boundary conditions you use, you still need a good grid distribution near the object if you want to resolve the gradients in the flow field.
  Reply With Quote

Old   February 6, 2006, 11:06
Default Re: Newbie Navier Stokes Questions + Grid
  #3
Jigar
Guest
 
Posts: n/a
but Is doing a simple grid dependecy check enough for near wall regions???? to get grid convergence??
  Reply With Quote

Old   February 6, 2006, 13:08
Default Re: Newbie Navier Stokes Questions + Grid
  #4
ag
Guest
 
Posts: n/a
Generally speaking no, unless you have some method a priori that allows you to know that the solution is grid-independent away from the walls.
  Reply With Quote

Old   February 6, 2006, 13:14
Default Re: Newbie Navier Stokes Questions + Grid
  #5
jigar
Guest
 
Posts: n/a
the reason iam asking these questions, is because the software that i use (Airpak from Fluent Inc) does not have the capability to compute y+. It is for indoor air simulation, and uses Navier Stokes for the whole flow domain
  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
Adding a term to Navier Stokes Equation ashtonJ CFX 3 January 15, 2011 07:32
navier stokes implementation in java gerhard Main CFD Forum 0 August 18, 2004 05:07
Navier stokes compresible viscid flow fea, somebody can help? Jose Choy Main CFD Forum 3 October 24, 2003 02:28
Parabolized Navier Stokes Howard Robbins Main CFD Forum 4 May 27, 2000 19:53
help: I am trying to solve Navier Stokes compressible and viscid flow Jose Choy Main CFD Forum 2 May 18, 2000 05:45


All times are GMT -4. The time now is 02:41.