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

[ANSYS Meshing] scale factor

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

Reply
 
LinkBack Thread Tools Display Modes
Old   December 22, 2011, 01:17
Post scale factor
  #1
New Member
 
arun km
Join Date: Dec 2011
Location: Chennai,India
Posts: 2
Rep Power: 0
arun km is on a distinguished road
dear friends....
i am new to ansys..i want to know how we can select scale factor?
and what is the relation between scale factor and max element size ?
arun km is offline   Reply With Quote

Old   December 22, 2011, 11:47
Default
  #2
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,650
Blog Entries: 1
Rep Power: 33
PSYMN will become famous soon enoughPSYMN will become famous soon enough
Scale factor lets you adjust all the sizes in the model at once...

By default, you should probably leave it as 1, which means that all the other sizes could be taken at face value.

Then if you want to make the model 20% coarser, you can come back and set the scale factor as 1.2. Get it?

Scale Factor times Max Element size gives you the largest element in your model. For Octree, this is the size of the initial subdivision when Octree is first initialized. You can read more about this in the theory sections of the Help.

If scale factor is larger than 1, it increases the mesh sizes throughout the model. If it is less than 1, it reduces them. Note, it changes how they behave, but it doesn't change the nominal values as you see them in the UI.
__________________
-----------------------------------------
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   January 2, 2013, 09:25
Default scale factor
  #3
New Member
 
Marina
Join Date: Apr 2012
Posts: 5
Rep Power: 4
Mmm2010 is on a distinguished road
ICEM CFD is unit - meter. I must create my geometry in millimeter. I made the geometry of the meters. I built grid. In Global Mesh Parameters field scale factor is 1 . I need to put 0.001 ? If to consider , that the geometry instead of millimeters built in meters? Thank You!
Mmm2010 is offline   Reply With Quote

Old   January 2, 2013, 10:16
Default
  #4
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,650
Blog Entries: 1
Rep Power: 33
PSYMN will become famous soon enoughPSYMN will become famous soon enough
Mmm2010, you could use the scale factor that way, and many do, but I would just scale the whole model (Geometry => Transform Geometry => Scale) (x 1000).

I find it is more robust if you are not dealing with lots of significant figures to the right of the decimal place. Rounding tends to cut things down a bit.

ICEM CFD is really unitless, which means it is based on what ever the units were when you imported. If you want to think in units, try "Settings => Model/Units".
__________________
-----------------------------------------
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   January 2, 2013, 12:01
Default scale factor
  #5
New Member
 
Marina
Join Date: Apr 2012
Posts: 5
Rep Power: 4
Mmm2010 is on a distinguished road
Thank you very much. In my case
If i do Geometry => Transform Geometry => Scale then X,Y,Z scale factor=0.001
or
In main menu ICEM CFD Info=>Toolbox=>Units (in Units.jpg) i do'nt know i can change the unit of distance? I need to calculate all?
Attached Images
File Type: jpg Units.jpg (56.4 KB, 19 views)
Mmm2010 is offline   Reply With Quote

Old   January 3, 2013, 03:26
Default scale factor
  #6
New Member
 
Marina
Join Date: Apr 2012
Posts: 5
Rep Power: 4
Mmm2010 is on a distinguished road
My source geometry is mm.
The action: Geometry => Transform Geometry => Scale then X,Y,Z scale factor=0.001 is good. I got the real geometry.Another way, distance in units i can to change? m=0.001 sm=0.01 mm=1 and etc. Or scale factor in Global Mesh Parameters if the topology is built? Thank you.
Mmm2010 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
Validity of Local Time Scale Factor kuhbuh CFX 4 March 26, 2010 16:15
Turbulence length scale and integral length scale rizhang CFX 1 September 10, 2009 06:38
advection time scale Tanveer ahmad Rubani CFX 1 February 24, 2009 16:16
scale factor amine CFX 0 February 18, 2008 04:25
local time scale factor selection mike CFX 0 April 19, 2006 08:52


All times are GMT -4. The time now is 00:43.