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-   -   [ICEM] Meshing of 3d flywing geometry (http://www.cfd-online.com/Forums/ansys-meshing/91906-meshing-3d-flywing-geometry.html)

sfs August 26, 2011 03:22

Meshing of 3d flywing geometry
 
hello everyone, can anyone plz suggest where can i get ICEM tutorials for 3d Airplane Geometry with all steps
plz do reply back, i tried in GAMBIT but i am not able to do meshing there for flywing geometry, so i want to try in ICEM software.
Max, Stuart, PSYMN...etc plz u guys also help me out, i am running out of time dudes....:)

Thank you, Cheers.
Vamshi

sfs August 26, 2011 13:24

plz anyone cud reply/suggest to my above message, i am new to this software
i request you to send me any tutorial of airplane geometry meshing in ICEM.

Vamshi

stuart23 August 31, 2011 20:26

Vamshi,

One of the tutorials in the tutorial guide describes how to mesh a half fuselage with wing. Just go to ansys.com, log in to the customer portal and look under documentation>ICEM. If you haven't already done so, you will need to sign up to the site.

Stu

sfs September 1, 2011 12:43

hello stuart, thanks for ur reply
In order to log into Ansys Customer portal, its asking Account Number (Customer Number), what is this actually mean and if so does Ansys charge anything for logging into Customer portal...

Vamshi

brunoc September 1, 2011 14:24

Hi sfs,

If you have a valid ANSYS license you can find your Customer Number by opening the ANSYS license manager and looking at 'Display Status > Display the Customer Number'.

Cheers

stuart23 September 1, 2011 22:18

Bruno is right. Also, this service is free. It has some very useful documentation as well as the latest updates to download

Stu

sfs September 2, 2011 02:43

thanks brunoc and stuart,
I will try to enquire about this from my institute and get a valid license from them so that i can register easily, as of wright now i am using crack version of ICEMCFD

stuart23 September 2, 2011 06:51

Vamshi,

I cannot endorse you using an illegal version of ICEM. Friends of mine, as well as others who frequent this site to offer their expertise are employees of Ansys. The licensing fees that us customers must pay make up their hard earned salary.

There is a free CFD suite called OpenFOAM which I would recommend for you to use. They have great support through this website and other communities.

Stu

sfs September 19, 2011 13:28

Hai Stuart,
Now i am using the ANSYS license version of our institute and can u plz help me out in how to proceed further for my geometry which is imported in STEP file format. Do i need to first repair my geometry or go ahead with assigning global mesh setup and so on.
My geometry is a bit complex(flywing geometry) with too many surfaces,points and curves in it and having symmetry. Can u plz help in letting me how to proceed in the form of some steps/procedure which i will follow and implement on my model.
Hoping for ur positive response.
Other members can also post ur views which will be a lot help to me and my work.


Vamshi

sfs September 19, 2011 14:37

hello stuart
You can look at my geometry in STEP file which is attached under:
http://www.4shared.com/file/lLV-DrSl/1_online.html

PSYMN September 20, 2011 13:27

Get some momentum...
 
SFS, we really recommend trying a few tutorials first... They are one step backward so you can take two steps forward... Walk before you run, etc...

Then get started on your project and ask questions after you are in motion... You can't steer a parked car.

Best regards,

Simon

sfs September 21, 2011 02:12

thanks simon for ur suggestion.
surely i will try some tutorials first and try to implement for my project
I just asked bcoz i was running out of time and i am new to this software, so i thought anyone could help me out.

Vamshi

sfs September 23, 2011 13:36

Hai Simon and Stuart,
As u have suggested i have done with some tutorials and now just started to work on my project. Initially itself its showing some error. when i tried to repair my geometry with giving default tolerence of 0.0002, its showing the following errors:
1) vertex part2_7_1.1894 is suspiciously far(.000170207) from curve FACE975e887 end
2) error-1 projecting(11.998693 6.895803 -0.202471) to pcurve of curve EDGE871 on surface FACE309 115
3) coedge revbit wrong on curve EDGE1778, surface FACE1777
4) curve EDGE186 far (0.00897421/0.0002) from coedge on surface FACE1760

If u want you can have a look at my geometry file which is attached in d following link: http://www.4shared.com/file/dy9tL5Qn/project1.html

Is it due to geometry problem or anything else, how can i get rid of these errors bcoz untill i remove them i cant proceed further. hoping for ur replies.


Vamshi

iare September 23, 2011 13:52

sorry u can even have my .tin geometry file which is attached with:http://www.4shared.com/file/dwQF43DY/project1.html

sfs September 23, 2011 14:07

.tin file is also attached alongwith : http://www.4shared.com/file/dwQF43DY/project1.html

sfs September 26, 2011 14:38

hello simon/stuart, can u plz tell me how to define parameters like scale factor, max element size and mesh density parameters. on what basis can we define them.
My geometry specifications are: length of the model is around 10,398mm. I have taken a domain(cube) 10 times the length of model, so now have can i define them based on these dimensions.
Can u plz suggest me how to define them.Hoping for ur replies atleast now.

Vamshi

PSYMN October 3, 2011 14:45

Programmers guide.
 
The scripting language uses tcl/tk.

You can measure and set the value to a $parameter.

You can create expressions with those parameters and set as $another_parameter.

You can use these parameters in place of things like mesh size or what ever...

Take a look into the programmers guide found under help. I think it even has some examples.

Best regards,

Simon

sfs October 13, 2011 07:56

hello simon,
I'm trying to understand how "Global Element Scale Factor" and "Global Element Seed Size" afftect mesh density.

In particular, any idea about how I can appropriately vary these parameters to get a desired mesh density will be appreciated. For example, if my goal is to obtain a total element of between 3million and 4 million, how do I vary these parameters to achieve this.Hoping for ur response

PSYMN October 13, 2011 10:50

The octree algorithm starts by subdividing the region inside and around the volume by elements of the max size specified, then further refinement happes from that size down to the specified entity size...

The Global Element Scale Factor is multiplied by the Global Element Seed Size to adjust the max size of that initial subdivision.

Keep in mind that Octree sizes are all powers of 2. you could have 5, 10, 20, 40 or you could have 1/8, 1/4, 1/2, 1, 2, 4, 8, 16, 32, etc. It can be a bit awkward to scale this up by some percentage (such as 10%) to get a slightly coarser mesh...

However, the Global Element Scale Factor makes it easy... If you set that to 1.1, it would just scale up all the sizes by 10% in each dimension... The volumetric element size would scale up by 1.1^3 and the number of elements would be scaled inversely (fewer larger elements)... To refine the mesh by ~10% you could use a Scale factor of 0.9.

Because the mesh size is defined before the mesh is generated, and the volume of the model is not known to the software before meshing, we can't just say "give 3 million cells". However, you can try an initial guess and then either ratchet the size up or down, or you could extract the mesh volume and calculate the appropriate size... For real meshes with complex geometry and various size mesh, a calculation would be very difficult, so we usually just size the mesh locally for our needs and then see how many cells are generated... I suppose experience helps.

sfs November 15, 2011 09:02

Flying wing configuration
 
hello simon and max,
1)when i am trying to build a topology with tolerance=0.5 i am getting yellow curves near the drageron surface, so how can i remove them so that i can get whole geometry in red curves. I tried to first create that particular surface from curve and then extract the curve from surface and again build topology now with tolerance value=0.3, but still it is showing the same, is there any other method to get rid of these single edge curves...

2)for my geometry if i want to create a finer mesh near the flaps and drageron(wingtip) as i need to study the characteristics and behaviour of the flow near these surfaces, how can i define the mesh parameters like no: of nodes, max size etc in icem cfd software, i mean the curve size parameters...


Thank you,
Vamshi


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