CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > ANSYS Meshing & Geometry

[GAMBIT] Grid Independency modeling - Grading meshes

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 1, 2010, 16:02
Exclamation Grid Independency modeling - Grading meshes
  #1
New Member
 
raviteja
Join Date: Mar 2010
Posts: 9
Rep Power: 7
vedravi is on a distinguished road
Hi,
I am working on turbulent pipe flows(2D Model in GAMBIT and Fluent 2d-Axisymmetric Analysis). Well, I need help regarding the inputs for grading meshes. For example the three mesh sizes, I am working on the same pipe, be 400x20, 800x40, 1600x80 (Fundamental exercises).
Now after analyzing the models (non graded mesh or uniform mesh), I see that the results are NOT GRID INDEPENDENT. Hence I started working on non uniform (graded) meshes for these mesh sizes. Well, for the First/Last Ratio type of grading,

Ratio = (last length/first length)^(1/n-1).
where n= no: of intervals on the edge

Now my Questions are
1) "Are we supposed to give same ratio to different mesh sizes i.e say 0.5 for both 800 intervals edge and 1600 intervals edge (or) are we supposed to provide separate ratios for checking GRID INDEPENDENCY?"

2) "How to consider/decide the value of last elemental length or first elemental length for a given edge so as to use those values in above formula to get the ratio?"

Thank you for your help
vedravi 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
Reynolds transport, turbulence model, etc Beginner Main CFD Forum 1 January 7, 2009 06:36
wall function and grid independency????? scott FLUENT 3 October 26, 2006 12:31
y+ values for grid in RANS modeling Vishwas FLUENT 1 January 14, 2006 13:38
Modeling Flow/Saturation/Absorption in Fibers Gene Dougherty Main CFD Forum 0 June 6, 2003 14:49
Numerical methods for discontinuous grid interfaces? Hansong Hang Main CFD Forum 12 September 16, 1998 22:26


All times are GMT -4. The time now is 04:34.