CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

High Skewness in Hexcore Mesh/ Tgrid

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

LinkBack Thread Tools Display Modes
Old   November 7, 2009, 08:55
Unhappy High Skewness in Hexcore Mesh/ Tgrid
New Member
Join Date: Oct 2009
Posts: 11
Rep Power: 9
xaero is on a distinguished road
Sponsored Links
I have the problem of a very high skewness at the hexcore mesh in the image below. (The model is a 3D- Scan of a Land Rover) I have wrapped the surface of this model and refined it down to a skewness of the boundary layer of 0.65. After inserting the bounding box and initializing a tetrahedral mesh upon the boundary layers, i did a hexcore mesh- which then resulted in a skewness of >.99 . Does anyone have any advice for me to bring it down? Is it because of the grubby wrapping surface? Or is there a better solution than intersecting fromn tetrahedrals to hexahedral cells?

Note:If you are wondering about the size of the bounding box: I am currently writing my first bachelor's thesis on the topic of grid generation in various software- the model is not intended to be solved in Fluent- so I kept the grid size small for faster grid generation results.

I would be very thankful for every advice given.
Greetings, Fabian
xaero is offline   Reply With Quote
Sponsored Links

Old   November 7, 2009, 12:14
Senior Member
John Chawner
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 253
Rep Power: 11
jchawner is on a distinguished road

I can't help you with you question but I was wondering if you'd be willing to share the results of your thesis when it's complete. It will probably be very interesting.
John Chawner / /
on Twitter: @jchawner
jchawner is offline   Reply With Quote

Old   November 7, 2009, 21:33
Senior Member
ztdep's Avatar
p ding
Join Date: Mar 2009
Posts: 317
Rep Power: 11
ztdep is on a distinguished road
Send a message via Yahoo to ztdep Send a message via Skype™ to ztdep
Dear friends:
It seems that we have somthing in common. i am writing a code for the adaptive cartesian grid solver.
Since you use the cartesian grid in most of the river, why not use it at the boudnary. the cartesian grid is very easy to adapt to your bondary.
ztdep is offline   Reply With Quote

Old   November 8, 2009, 20:24
New Member
Join Date: Oct 2009
Posts: 11
Rep Power: 9
xaero is on a distinguished road
Thank you for your responses

Of course I can share the results of my thesis with the community. It will be completed at the end of this month. However, it might only be interesting for beginners in Tgrid and Gambit as I only compare these two programs regarding meshing possibilities and results in skewness.

Do you mean to apply the cartesian grid upon the bounding box? I never thought of that- but it sounds plausible I will try it tomorrow an then post my results!

greetings, Fabian
xaero is offline   Reply With Quote

Old   November 10, 2009, 12:04
New Member
Join Date: Oct 2009
Posts: 11
Rep Power: 9
xaero is on a distinguished road
Hello again,
I have tried the advice of ztdep to apply a cartesian grid over the bounding box. Sadly it resulted in the same high skewness.
Then i tried the keep outer domain- function provided in the hexcore controls menu to create a bounding box. That finally worked and brought the skewness down below 0.8

Hint: Because the initial cell count for generating a outer domain is limited by 1.500.000, it has to be increased manually with the TUI command mesh/controls/hexcore/maximum-initial-cells

greets, Fabian
xaero is offline   Reply With Quote


tgrid high skewness

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
Mesh skewness Woo Meng Wai FLUENT 3 June 20, 2010 10:04
Mesh skewness warning how to get rid ploceus OpenFOAM Native Meshers: blockMesh 2 July 1, 2009 05:01
How to control Minximum mesh space? hung FLUENT 7 April 18, 2005 09:38
Tgrid mesh Samir FLUENT 1 February 17, 2005 06:57
unstructured vs. structured grids Frank Muldoon Main CFD Forum 1 January 5, 1999 11:09

Sponsored Links

All times are GMT -4. The time now is 05:40.