CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Aircraft Mesh Recommendation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 30, 2006, 16:25
Default Aircraft Mesh Recommendation
  #1
Sami
Guest
 
Posts: n/a
I have only recently started using Fluent/Gambit and I am looking for recommendations on the best method to mesh an aircraft in 3D. (I only have access to Gambit and will not have any other mesh generation software available).

I wish to model a small scale RC aircraft. The aircraft is approximately 3 metres in length, has a chord length of 0.25 metres and will fly at 30 mph.

I have tried to use the boundary layer mesh function, which works good for part of the fuselage, but around the wing and where it connects to the fuselage I always get highly skewed mesh. I then followed the Gambit tutorial for meshing an aircraft, but this results in a y+ value in my simulation that is pretty large (around 150). For the S-A solver, the User Guide recommends a y+ as small as 1. I have made the mesh smaller, but this doesn't reduce y+ by much yet takes a lot longer to run.

Therefore I am wondering if anyone has a standard method/recommendations for meshing an aircraft.

Thank you any assistance,

-Sami
  Reply With Quote

Old   March 30, 2006, 18:54
Default Re: Aircraft Mesh Recommendation
  #2
Riaan
Guest
 
Posts: n/a
The SA turbulence model is good for y+<1 and 30<y+<300, so if you are getting y+ 150, you are just fine.

Make sure you use T-grid, and build at least 5 prismatic cells in your boundary layer, and ensure that your mesh smoothly transitions from your boundary layer cells to your domain tet-cells.

Anycase, use T-Grid for volume meshes with boundary layers. It does take some time to learn, but is worth the effort (T-grid is part of the FLUENT package).

I only use Gambit to import and clean the geometry, build the surface meshes, and set the boundary conditions. The boundary layers are volume meshes are all done in T-Grid.

For a R/C aircraft, you should be carefull of low-reynolds number effects, and that your boundary layers may be laminar for a large % of chord. In Fluent, adding the turbulence models, means that all your boundary layers will be turbulent from the get go.

  Reply With Quote

Old   April 2, 2006, 13:23
Default Re: Aircraft Mesh Recommendation
  #3
riaan
Guest
 
Posts: n/a
*Edit

SA good for Y+<1 and 30<y+<300
  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
engrid -> save as .stl with boundarie codes Zymon enGrid 31 August 29, 2011 13:40
ICEM aircraft mesh trailing edge difficulty MontyR ANSYS Meshing & Geometry 4 July 23, 2011 21:46
Gambit Mesh for Nsoe Cone, Fuselage and Aircraft Vincent Ryan FLUENT 1 March 17, 2011 09:38
2d irregular grid Remy Main CFD Forum 1 December 22, 2008 04:49
basic of mesh refinement arya CFX 4 June 19, 2007 12:21


All times are GMT -4. The time now is 23:35.