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-   -   [GAMBIT] Need help with meshing 3D Delta wing (http://www.cfd-online.com/Forums/ansys-meshing/96290-need-help-meshing-3d-delta-wing.html)

tuantran January 18, 2012 10:14

Need help with meshing 3D Delta wing
 
I'm doing an analysis of a Delta wing at low speed ( when the airplane is landing) and I want to use Gambit to mesh the 3D Delta wing geometry. But I'm new to Gambit, so I'd like to ask you some questions :D

Here is my idea:
http://www.flickr.com/photos/74522469@N03/6712831701/

I divide the flow area into some blocks like they are in the image: for the view from above, we can see that there are 8 sections, and the same for the side view.

I'd like to have more mesh at the angles of delta wing. Thus, can you tell me how can i do it step by step ?

I don't know how to create those 8 sections. Should I create points then connect them by Virtual line ??

I only simulated a 2D Naca airfoil. But for this case, I don't know how to do. Please help me :D. I'm looking forward to seeing your reply.

Thank you in advance.

Far January 18, 2012 11:37

What do you mean by eight sections? Do you want to work on 2d?

tuantran January 19, 2012 11:12

http://www.flickr.com/photos/74522469@N03/6725839671/

This is the 3D drawing geometry. Although it's an incomplete drawing, but i hope it's not difficult to understand :D

Far January 19, 2012 11:44

do you have coordinates of your wing? If not create them MS Excel, then we can import them in gambit and after that we can start our process.
As I see there are total four points on 2-d section. Is there any taper or change of chord length?

tuantran January 20, 2012 02:40

looking down from above, the wing is a trapezoidal with the lengths of the parallel sides are 200mm and 2 mm, and the height is 172mm. The thickness of the wing is 2mm.
at present, there's no taper or change of chord length. I will count these ones in later simulation to compare.

tuantran January 22, 2012 01:33

Still looking for some helps :D

Far January 22, 2012 02:06

Quote:

looking down from above, the wing is a trapezoidal with the lengths of the parallel sides are 200mm and 2 mm, and the height is 172mm. The thickness of the wing is 2mm.
at present, there's no taper or change of chord length. I will count these ones in later simulation to compare.
Make four points : (0,0), (200,0), (99, 172), (101, 172) and copy them in z-direction with relative distance of 2 mm. Join them with 12 edges and then construct faces (6 faces in total). After this we shall discuss about the domain and meshing.

tuantran January 22, 2012 04:38

Thanks Far. I've already done that. So, what's the next step? Can u tell me the outline ?

Far January 22, 2012 04:50

flow is subsonic or supersonic? What is the objective of this study?

tuantran January 22, 2012 08:40

flow is subsonic. The goal of this study is to research about the Delta wing at low speed ( when airplane is landing). After the simulation by ANSYS, I will compare that result to the experimental result ( using wind tunnel, so the speed is about 10, 15, 30 m/s)

Far January 23, 2012 17:03

make hemisphere domain from wing to at least 15 chords upstream and then connect with circular cylinder domain with at least 25 chords downstream. This is necessary since Reynolds number is very low and I am excepting higher angle of attack (correct me if I am wrong). Then subtract the wing volume from this far field body.

For quick simulation you may create the 3D boundary layer on wing and meshing the rest of domain with tetra.

Flow is laminar, turbulent or transitional? Are you interested in resolving the separation? What other flow features are expected in flow?

tuantran January 23, 2012 23:34

I've already done the subtraction step. For the quick simulation, I can do it. However, I need to mesh the volume like the graphic which i sent above, but I don't know how to divide the flow domains like that to mesh them.

The flow is transitional and the AoA is high.

Some pictures of delta wing simulation on the internet:
http://www.onera.fr/photos-en/simula...ta-sillage.php

http://www.google.com.vn/imgres?q=de...0&tx=110&ty=53

Far January 24, 2012 00:12

hemisphere inlet
 
The mesh topology you have just shown in above Fig. can be easily constructed and meshed within few minutes. I would like to suggest you to consider making the hemisphere in inlet region (as discussed above) in order to specify the high AOA.

I shall post some images and dbs file of your geometry today (if possible :cool:).

tuantran January 24, 2012 12:19

Hehe, that sounds good :D. I'm looking forward to seeing it :D

Far January 24, 2012 13:34

here it is
http://img687.imageshack.us/img687/2069/deltawing.jpg

tuantran January 24, 2012 21:09

Thanks Far. It looks great. Did u create it by Gambit? Can u send me the file plz?

And 1 more thing, the point is I don't know how to create those lines:
http://img854.imageshack.us/img854/5...ddeltawing.jpg

Thank you :D

Far January 24, 2012 22:21

Although meshing was done by ICEM but same topology can be easily created within GAMBIT (obviously with more work of making vertices, edge, faces and may be volumes).
http://img191.imageshack.us/img191/9...tawing2001.jpg
I am also sharing ICEM files here
http://www.4shared.com/rar/w5TTdWKW/deltawing.html

tuantran January 25, 2012 20:21

Hehe, thank you so much. Let me see this first :D

yatindra kashyap January 29, 2012 12:54

Meshing Double Delta Wing
 
Hi

I am working on the same problem of delta wing but it is double-delta wing
I have meshed the surface of delta wing and the domain surface but getting problem on volume meshing of the domain......the problem is 32bit version ...? I need advice on this how to perform the meshing operation of the domain within 32bit limit......Using Gambit ,winxp,dual core,2gb:confused:

yatindra kashyap January 29, 2012 13:18

Quote:

Originally Posted by yatindra kashyap (Post 341751)
Hi

I am working on the same problem of delta wing but it is double-delta wing
I have meshed the surface of delta wing and the domain surface but getting problem on volume meshing of the domain......the problem is 32bit version ...? I need advice on this how to perform the meshing operation of the domain within 32bit limit......Using Gambit ,winxp,dual core,2gb:confused:

the file link is :
https://rapidshare.com/files/1131190...fece_mesh2.rar

also please tell me how to take snapshot of this delta wing from gambit:o


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