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

[ANSYS Meshing] Meshing small air gap between parallel disks

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 31, 2016, 08:46
Default Meshing small air gap between parallel disks
  #1
New Member
 
Alexandros
Join Date: Jun 2016
Posts: 28
Rep Power: 9
AlexRonto is on a distinguished road
Hello all,

I do a CHT analysis at an electric generator. So I have 2 rotating disks (rotors) with a protrusion at their periphery and a stationary rim between them (stator). Inside the rim I have there are the coils of the machine. The rotating discs' diameter is 0.7m and the air gap between each disk and the stator is 4mm. The meshing is done at ICEM.

I firstly tried to put a sizing control with an automatic method so the elements are small enough near the walls (rotating and stationary) and the mesh I achieved is the one at the picture 5. (I suppose the triangles is not a good choice, as they create skewed elements and they do not capture the boundary layer region of the air gap properly.) However, the results are no good for the heat transfer. I have much higher temperatures than the ones I expect.

I then tried to put inflation layers near the wall boundaries, but ICEM could not create them for some reason.

So, my question is 1), if the the mesh that I have created could be the reason for the bad calculation of Heat transfer from the solver (I use Automatic wall function for the turbulence) .
And 2), supposing the problem of the bad results is the mesh, does anybody have any suggestions about the meshing options for the current geometry?

Thanks in advance!
Attached Images
File Type: jpg Pic 1.jpg (74.3 KB, 50 views)
File Type: jpg Pic 2.jpg (51.8 KB, 37 views)
File Type: jpg Pic 3.jpg (52.9 KB, 34 views)
File Type: jpg Pic 4.jpg (191.4 KB, 33 views)
File Type: jpg Pic 5.jpg (149.2 KB, 33 views)
AlexRonto is offline   Reply With Quote

Old   November 4, 2016, 08:02
Default
  #2
Senior Member
 
Gweher's Avatar
 
Gwenael H.
Join Date: Mar 2011
Location: Switzerland
Posts: 392
Rep Power: 20
Gweher will become famous soon enough
Hi Alexandros,

As you're using ICEM you should take advantage of the blocking capabilities of the software. Start with an initial 3D blocking, slice it and assign the edges to the curves and faces to the corresponding surfaces.
I would also recommend reading the cfd wiki for basic CFD analysis guidelines, especially for BL.
Gweher is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Air Gap modeling in Thermal Analysis Ruham ANSYS 0 February 1, 2013 09:21
Parallel meshing + simulating. need Help nicolarre OpenFOAM 2 April 11, 2011 11:04
Compressible Flow through small gap Andreas FLUENT 0 May 19, 2006 10:11
CFX5.6 (Build) Parallel Meshing David Hargreaves CFX 2 January 12, 2005 12:39
parallel mode - small problem? co2 FLUENT 2 June 1, 2004 23:47


All times are GMT -4. The time now is 17:01.