mesh of a spinnaker
 

Any idea about meshing this geometry?
I am not looking for an accurate mesh for the moment.. just need some guidelines to proceed.
The idea is of course to have the mesh more fine close to the sail and coarser away from it. I was thinking about an unstructured mesh, but if anybody knows about a structured one is well accepted.
thanks in advance

michele

I took a look at you geometry. problem i find is Thickness. it's completely ignoring the geometry inside. This is an interesting case, first time i deal with it. I'm quite sure thickness is the problem. Where did you draw your geometry ? if in Ansys modeler, can you attach an IGES file of your geomtry from design modeler

Sorry for replying after so many days, but I was busy. Any suggestion is really appreciated

TRM_SRF has a thickness or it is a surface?

it is a surface?


ok it ishttp://www.google.com.pk/imgres?imgu...PUBMAg&dur=350

http://en.wikipedia.org/wiki/Spinnaker

yes it is only a surface without thickness

I built the mesh, but how to make fluent or cfx will "see" an impenetrable surface without thickness.

@ Ralen:
Just give the boundary conditions of the sail as a wall

Which software did you use for creating the mesh?
thank you a lot in advance for your help

This for Fluent. And for CFX a message "Select a BC type." Wall is not acceptable.

Here are the files.
Need some modifications to improve the quality.

pics
 

pics :

http://img36.imageshack.us/img36/616/66819953.png

http://img832.imageshack.us/img832/111/58871591.png

More pics
 

http://img692.imageshack.us/img692/1593/84815376.png

http://img706.imageshack.us/img706/9286/31458680.png

Do not specify bc in ICEM. CFX will automatically get the boundary condition using the named selection.

Also use import mesh option in CFX-pre to read the mesh in .cfx or .cfx5

Thank you a lot it has been very useful!

Ralan's topology has the better quality than mine.

Ralan: Could you please check both and indicate what's the difference?


Since your case has surface in 3d , therefore in ICEM one has to explicitly project the faces to the wall of surface geometry.

Named selection for BC for CFX
 

For example, inlet/in will have the inlet boundary and outlet/out will have the outlet boundary. similarly wall has the wall condition.

If your naming scheme does not fulfil these requirments still, specifying the different boundaries will give you option to select them later in CFX pre.

Just right click on the component(your geometry) in CFX-Pre and insert new boundary. In this way you can specify wall, symmetry etc. BCs for the remaining boundaries.

Yes, I associate the faces to the sail surface.
I built o-grid mesh only for the sail. You built for area around sail. I also used the internal o-grid.

Like this
 

Like this ? But still quality is low!!!!

http://img692.imageshack.us/img692/9412/90916891mh.png

The mesh extent is not enough in the y- and Z-direction. It is a low velocity simulation and you need at-least 10-15 lengths upstream and 20-25 lengths downstream.

Like this.

OK. Internally I have made the o-grid, while around sail it is C-grid. And making o-grid down and upper side, make the quality worst.

On the sail and around the sail mesh size is 0.1 (40 nodes). Global mesh size 2. Mesh ~5600000 hexa. Is it good?

Keep it under 0.5-0.8 million

The same size of cells. The difference in quality is minimal. The mesh size without external o-grid 1617380, with - 1836202.

The mesh topology is excellent. Would you like to share it!!!!

Would it be possible to have a replay file in order to see the steps you did?
thank you

You need replay file? I did not make it, may be Ralan did it.

But it can be made easily, if required.

Ralen is correct.
Replay will be later. When I will find a freeware program for recording. :)

he is not asking for recording of session, rather he is asking for replay script ;)

yes, the equivalent of journal file in gambit.
or if it is not possible, just the principal steps of the blocking strategy.
thank you guys

How to make it? :confused:

File >>> Replay scripts > recording scripts

Also described here
http://www.youtube.com/watch?v=EknKVAJGEJ8

This is the replay file. Not for my previous attached project, but all the same except size and external o-grid.

Just going to post replay file and youtube clip.

Here it is replay script along with YouTube link http://www.youtube.com/watch?v=IInAR...ature=youtu.be

This is the simply example. The CFX doesn't see the WALL.

are you talking about internal wall?

I can see all boundary conditions in CFX. Use associate face to surface command.

Thanks. I forgot to do one of basic things. :D