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

Problem Meshing Airfoil

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 19, 2009, 19:12
Default Problem Meshing Airfoil
  #1
New Member
 
Join Date: Apr 2009
Location: Mexico
Posts: 7
Rep Power: 8
erodv is on a distinguished road
Hi ,

It's my first post as openFOAM 1.5 user, I meshed an airfoil but it's supposed that it should have a zone without mesh in the airfoil region, although I see the airfoil boundary, the mesh doesn't take care. It would be OK if someone take a look of the mesh and airfoil boundary pictures attached.

Thank you.
Attached Images
File Type: jpg Airfoil_mesh.jpg (57.9 KB, 416 views)
File Type: jpg perfil.jpg (30.3 KB, 260 views)
erodv is offline   Reply With Quote

Old   June 21, 2009, 04:16
Default
  #2
New Member
 
Daniele
Join Date: May 2009
Location: Rome, Italy
Posts: 7
Rep Power: 8
dani is on a distinguished road
Send a message via MSN to dani
Hi erodv,

may I ask you some things?
In particular:
1) do you define a block inside the airfoil?
2) is your mesh 3D? (or is it only a display effect?)

Regards,

Daniele
dani is offline   Reply With Quote

Old   June 22, 2009, 19:03
Default (SOLVED) Sorry, it was an error defining the blocks
  #3
New Member
 
Join Date: Apr 2009
Location: Mexico
Posts: 7
Rep Power: 8
erodv is on a distinguished road
Hi,
Sorry, I defined blocks intersecting the inner airfoil section, that was the problem, now all is ok with the mesh. Thanks to Dani for take the time to post.
erodv is offline   Reply With Quote

Old   June 24, 2009, 04:11
Default
  #4
New Member
 
Daniele
Join Date: May 2009
Location: Rome, Italy
Posts: 7
Rep Power: 8
dani is on a distinguished road
Send a message via MSN to dani
Not at all, erodv!

May I ask you a thing?
Do you have an experience with mesh generators different from blockMesh? If yes ... what's the best for external flows in your opinion?

Many thanks

Daniele
dani is offline   Reply With Quote

Old   June 24, 2009, 16:05
Default
  #5
New Member
 
Join Date: Apr 2009
Location: Mexico
Posts: 7
Rep Power: 8
erodv is on a distinguished road
I don't have experience with open source mesh generators, but I found something about a programm called gmsh, the mesh generated can be imported into openfoam, (i don't try it yet). And from the commercial ones, there are many options, for example Fluent - Gambit meshes can be imported into openFOAM.
erodv is offline   Reply With Quote

Old   June 26, 2009, 09:25
Default
  #6
Senior Member
 
Wolfgang Heydlauff
Join Date: Mar 2009
Location: Germany
Posts: 136
Rep Power: 8
wolle1982 is on a distinguished road
hi dani, hi erodv,

I also meshed many airfoil in my diploma thesis and collected much experience.

1. salome is feasible to mesh airfoils, but the mesh quality is not that good.
2. Blockmesh can mesh an airfoil very quick with only 6 blocks
3. if you want to mesh many airfoils with a very excellent mesh, you can creat many many blocks. so eg. i have and airfoil spline/polyline with 180 vertices, then I create a mesh consisting of 180 blocks. between each vertex one block. therefore you need to take those vertices and translate them rectangle to the surface to create the matching vertices.
since the topology of blockMesh is very simple and always works after the same procedure, one can automatizes this work in excel with VBA eg.

to make it clearer, I attached some pictures. the resulting mesh then is very good.

remember: since you probably are solving with simpleFOAm or turbFoam, the y+ value should be around 30. don't make the mistake and shrink it to 1. 1 only works with icofoam or LES.
Attached Images
File Type: jpg 2.JPG (72.0 KB, 278 views)
File Type: jpg uberGitter3Nase.jpg (98.3 KB, 786 views)
File Type: jpg uberGitter3Overview.jpg (96.8 KB, 832 views)
File Type: jpg Unbenannt.JPG (68.7 KB, 666 views)
wolle1982 is offline   Reply With Quote

Old   June 29, 2009, 02:12
Default
  #7
New Member
 
Marcin Hinz
Join Date: May 2009
Location: Monheim am Rhein, Germany
Posts: 24
Rep Power: 8
Marcin is on a distinguished road
Hi everyone!

I also simulate some airfoils with OpenFOAM. However things I try to simulate are part of a gas turbine, so I need a compressible solver with turbulence modelling possibility. I use the rhoSimpleFoam. All my meshes are imported from Turbogrid. I try to compare my results to CFX but they are still different mainly in the dissipation. Have you maybe already done some comparasions of OpenFOAM to commercial codes? Do you have maybe some experience you would like to deal with? I would be pleased for any anwser.

Regards, Marcin.
Marcin is offline   Reply With Quote

Old   June 29, 2009, 21:03
Default
  #8
New Member
 
Join Date: Apr 2009
Location: Mexico
Posts: 7
Rep Power: 8
erodv is on a distinguished road
Hi Marcin,

No, I don't have experience simulating the gas turbine, I'm relative new in both commercial and open source codes.
erodv is offline   Reply With Quote

Old   December 2, 2009, 19:02
Default
  #9
Senior Member
 
Eric Nutsch
Join Date: Sep 2009
Location: Eugene, Oregon USA
Posts: 112
Rep Power: 7
ericnutsch is on a distinguished road
Send a message via Skype™ to ericnutsch
Hi wolle1982,


What code did you use in blockMesh to create your spines?

I attempted using the function simpleSpline, in the format "simpleSpline A B ((i j k) (l m n))" with no luck.

Thanks for your help!
ericnutsch is offline   Reply With Quote

Old   December 7, 2009, 10:54
Default
  #10
Senior Member
 
Wolfgang Heydlauff
Join Date: Mar 2009
Location: Germany
Posts: 136
Rep Power: 8
wolle1982 is on a distinguished road
hi,

nether...nor. Using my math-knowledge, I programmed a function in excel that creates a spline consisting of many points with a definable gradient at the end and at the beginning. with those points I created a usual "polyLine". this makes good results. I hope some day a new OF version corrects that bug.

good luck.
wolle1982 is offline   Reply With Quote

Old   April 3, 2010, 12:59
Default airfoils with openfoam
  #11
New Member
 
Prasanth V
Join Date: Mar 2010
Posts: 6
Rep Power: 7
vprasu is on a distinguished road
Hai everybody. I am new to OpenFOAM .I need to work with some airfoil geometry in OpenFOAM. I used to mesh an airfoil in gambit and solving it using fluent (2D). I need to do it with OpenFOAM , I tried import gambit mesh to OpenFOAM but it failed with some error messages. can anybody give me an idea about converting the fluent mesh file to OpenFoam and solving it with the same.
Thank you

Last edited by vprasu; April 3, 2010 at 13:27.
vprasu is offline   Reply With Quote

Old   April 13, 2010, 21:44
Default
  #12
New Member
 
maverick
Join Date: Feb 2010
Posts: 9
Rep Power: 7
maverick is on a distinguished road
Quote:
airfoils with openfoam
Hai everybody. I am new to OpenFOAM .I need to work with some airfoil geometry in OpenFOAM. I used to mesh an airfoil in gambit and solving it using fluent (2D). I need to do it with OpenFOAM , I tried import gambit mesh to OpenFOAM but it failed with some error messages. can anybody give me an idea about converting the fluent mesh file to OpenFoam and solving it with the same.
Thank you
hi prasanth
am also doing a cascade airfoil problem,why dont you post your error message
maverick is offline   Reply With Quote

Old   January 11, 2012, 18:46
Default
  #13
New Member
 
deepaktbabu
Join Date: Nov 2011
Posts: 5
Rep Power: 5
deepaktbabu is on a distinguished road
can anyone tell me how C grid is made in salome ??
deepaktbabu is offline   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
2D SST Simulation Airfoil - Convergence Problem Kraemer CFX 10 April 16, 2011 07:22
Meshing airfoil Wason FLUENT 6 November 8, 2009 12:50
[GAMBIT] NACA0012 meshing problem parvez2683 ANSYS Meshing & Geometry 3 June 24, 2009 00:46
Meshing problem Sanjay Jain FLUENT 6 April 5, 2008 09:51
Oscillating airfoil problem ganesh Main CFD Forum 2 June 27, 2005 13:57


All times are GMT -4. The time now is 08:39.