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

[ICEM] Meshing Size Problem

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 14, 2011, 09:48
Default Meshing Size Problem
  #1
Senior Member
 
Join Date: Dec 2010
Posts: 135
Rep Power: 16
eRzBeNgEl is on a distinguished road
HI Guys

I am using Icem CFD 12.1 and I need help with following problem.

My standard Model consists of 500.000 Elements.
My Global Size Setup is:
Skale Factor: 1
Global Mesh Size: 32
Proximity Based Refinement - Activated : Min Size Limit 1

For getting a higher mesh resolution I created a Density and set the Size to 16! Now i got a Mesh of 750000 elements.

Well the next step is to increase the mesh size to 1.000.000 elements. When I enter now in the Density Mesh size 15. the total number of elements increases to 22.000.000! I don't get it? What I am doing wrong?

Thanks for help
eRzBeNgEl is offline   Reply With Quote

Old   April 16, 2011, 12:56
Default Octree Powers of 2
  #2
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,663
Blog Entries: 1
Rep Power: 47
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Octree refinement works in Powers of 2... Actually powers of 2 based on your minimum size, and then multiplied by your scale factor...

If you change the max size in your density from 16 down to 15, it drops to the next power of 2, which is 8. In 3D space, and worse with tetras in clumps of 12, that very quickly increases your number of elements.

If you just want to tweak your mesh size a little, use the scale factor. Change it from 1.0 down to 0.9 and see how it goes...

This would mean that your size 16 would become 16*0.9 = 14.4...

You can read more about Octree powers of two in the help or on many other cfd-online postings.
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN is offline   Reply With Quote

Old   April 17, 2011, 16:53
Default
  #3
Senior Member
 
Join Date: Dec 2010
Posts: 135
Rep Power: 16
eRzBeNgEl is on a distinguished road
Thanks a lot! I got it now :-)
eRzBeNgEl is offline   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
[GAMBIT] 3D boundary layer and meshing problem in GAMBIT 2.4.6 prashanthreddyh ANSYS Meshing & Geometry 1 December 20, 2011 01:35
problem meshing with low y+ cesco FLUENT 8 February 23, 2009 06:12
Problem meshing with Gambit Adrian FLUENT 8 October 7, 2008 09:39
problem meshing in GAMBIT khairul hadi Main CFD Forum 1 August 20, 2008 18:13
Gambit Meshing volume problem haamdy FLUENT 11 August 10, 2007 09:39


All times are GMT -4. The time now is 21:57.