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

Inflation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 9, 2005, 18:52
Default Inflation
  #1
Gab
Guest
 
Posts: n/a
Hi, All

I try to use inflation in meshing. The problem I got is that I can only creat inflation layers on certain faces in my geometry. If I choose more or all the faces, it did not show error but gave me no inflation layers.

I tried many times but still haven't figure out the rules of using inflation.

Can someone help provide me some tips on using inflation? Is it possible/necessary to generate inflation layers on all faces?

Thanks

Best regards!

Gab
  Reply With Quote

Old   August 10, 2005, 10:06
Default Re: Inflation
  #2
Gab
Guest
 
Posts: n/a
Sorry, I am using cfx-mesh.

Regards!

Gab
  Reply With Quote

Old   August 10, 2005, 15:54
Default Re: Inflation
  #3
Paul Lewis
Guest
 
Posts: n/a
Hi Gab,

The use of inflation layers in the near wall region creates cells that are aligned to the direction of the flow (i.e. along the wall). If possible, it's best to use 10-15 layers in the boundary layer region. Using the settings in CFX mesh you can fine tune the thickness of the layers. The layer nearest the wall needs to be changed until you get a y-plus figure of the correct magnitude for the turbulence model you are using. Scaleable wall functions mean that result should be independent of y-plus lower than 11. The outer layer should be of a similar thickness to the "default body spacing", this ensures there is no sudden change in cell size at the edge of the inflated layer.

I have had problems in the past creating inflation layers on multiple surfaces. Try not to select the composite surfaces from the tree, instead select each surface directly from the model using the mouse.

Good Luck

Paul
  Reply With Quote

Old   August 10, 2005, 23:52
Default Re: Inflation
  #4
Gab
Guest
 
Posts: n/a
Thanks, Paul

I tried as you suggested. It works for some faces, but not all. I check the cfx-mesh help file, it says that 'Inflation can be applied to all ordinary boundaries but not to boundaries specified as a Periodic Pair'. So I suppose that the inflation function should works for all the faces in my mesh.

I also observed that the problem comes whereever three adjoining faces (for example three adjoining faces of a box)were defined as inflation. What can I do in such cases?

Thanks!

Regards!

Gab
  Reply With Quote

Old   August 11, 2005, 02:16
Default Re: Inflation
  #5
Gab
Guest
 
Posts: n/a
I have solve the problem. The inflation layers actually were there, I just was not able to view them from surface mesh.

Regards!

Gab
  Reply With Quote

Old   August 11, 2005, 04:17
Default Re: Inflation
  #6
Helper
Guest
 
Posts: n/a
Try changing the Preview setting - "Display Mesh" to "Inflated Mesh" and then only the prismatic/inflated mesh will be displayed.
  Reply With Quote

Old   August 24, 2005, 22:45
Default Re: Inflation
  #7
Hamid
Guest
 
Posts: n/a
hi dear you have selected the face that belong to fluid side which means that the face you have there to inflate belongs to a solid domain. supress those bodies that you don't need then chose the face that you need the iflation to grow with in it. let me how you did. Rgards Hamid
  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
Total Thickness of Inflation Layer prikeyma CFX 5 August 28, 2020 03:22
Add inflation on a laminar flow xyq102296 ANSYS Meshing & Geometry 0 October 21, 2010 07:37
Large Valve Flow Analysis - Inflation Problem sercan85 ANSYS Meshing & Geometry 2 June 1, 2010 14:02
question about inflation for impeller sandy CFX 4 August 8, 2007 09:03
inflation Jennifer Haque CFX 2 June 9, 2004 18:55


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