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-   -   [ICEM] Block refinement button (https://www.cfd-online.com/Forums/ansys-meshing/105743-block-refinement-button.html)

Anna Tian August 8, 2012 03:49
Block refinement button
 
2 Attachment(s)
Hi,

May I ask a question about the ICEM button 'Blocking -> Pre-Mesh Params -> Refinement'?


I'd like to use this button to coarsen my mesh. The ICEM help tells

'
A Level value greater than 1 will result in refinement, while a Level value less than 1 will result in coarsening of the pre-mesh.
'

But when I set the level as the value as 0.8 or 0.5, it doesn't work. ( see the attached picture )
http://www.cfd-online.com/Forums/dat...AAAElFTkSuQmCC

But actually I did put positive values there. ( like 0.5 and 0.8 are positive )

Could you please tell me how to solve this problem?

Far August 8, 2012 04:03
instead of 0.5 put 1/2, for 0.25 use 1/4 and so on. Also 4/5 for 0.8

Anna Tian August 8, 2012 04:25
Quote:
Originally Posted by Far (Post 375970)
instead of 0.5 put 1/2, for 0.25 use 1/4 and so on. Also 4/5 for 0.8
It works. Haha...:D

But may that reduce my pre-mesh quality?

Far August 8, 2012 11:36
may be, but it depends upon ur solver. For example "Fluent requires 2:1 refinement or vice-versa and CFX requires 3:1 refinement". You can later edit this is edit mesh menu so that you have 1:1 after refinments

From ICEM Help

Quote:
Resolve refinements
is used to resolve couplings, which define the connectivity between elements which are not connected node by node (hanging nodes). In order to accommodate solvers that cannot handle couplings, this method can be used to resolve couplings using refinement and to make the mesh more conformal.

Anna Tian August 11, 2012 12:41
Quote:
Originally Posted by Far (Post 376055)
may be, but it depends upon ur solver. For example "Fluent requires 2:1 refinement or vice-versa and CFX requires 3:1 refinement". You can later edit this is edit mesh menu so that you have 1:1 after refinments

From ICEM Help
Doesn't this block refinement button always work very badly? I use non-uniform mesh. Sometimes 1/10 gives finer mesh than 1/3. And sometimes the mesh at some areas even disappear. Sometimes all the mesh disappear. Is there a better way to do the mesh coarsening instead of this button? What about the mesh refinement button 'edit mesh -> adjust mesh density' ?

Far August 11, 2012 12:45
Quote:
Originally Posted by Anna Tian (Post 376595)
Doesn't this block refinement button always work very badly? Sometimes 1/10 gives finer mesh than 1/3. Sometimes all the mesh disappear. And sometimes the mesh is not uniform any more. (Mesh at some areas even disappear. ) Is there a better way to do the mesh coarsening?
I dont think so that 1/10 produces finer mesh than 1/3 . can you please post some relevant pics?


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