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-   -   ICEM meshing question (https://www.cfd-online.com/Forums/ansys-meshing/77015-icem-meshing-question.html)

gsbhatia89 June 10, 2010 08:33

ICEM meshing question
 
Hey everybody,

I had a question for a beginning mesher in ICEM

I have a complex 3d geometry that needs to be meshed in quite some detail and ansys mesher isnt enough to do the job. (Image is attached herewith)

http://img202.imageshack.us/i/crossmodel.png/

It is a long tube in which there is intersection of two tubes and there are five holes in this intersecting tubes through which fuel is injected into the main tube containing air.

I wished to ask you if it possible to somehow import the solid model into ICEM so that the geometry creation is easily done or should I begin the geometry from scratch in ICEM. If I have to do it directly in ICEM, do you have any ideas on how I could go about meshing this model...

I would be really happy if somebody could let me know something about it..

Regards,
Gagan

PSYMN June 11, 2010 08:13

Either way...
 
Yes, this geometry could be created in ICEM CFD... It is just circles extruded, intersected and trimmed. But if you have it in another format, you can just import it into ICEM CFD. Is this model done in DM? In ICEM CFD, top left corner File => Workbench Readers. Or your could export it from DM as an ICEM CFD Tetin file. ICEM CFD can also read ACIS, DWG/DXF, RHINO, STL/VRML, STEP/IGES, etc. If you have the CAD reader keys, you could read it in from Parasolid, CATIA, Pro/E, Solidworks or UG...

I am surprised to read that you couldn't get a good mesh on this with the ANSYS mesher (it is a pretty simple geometry). What kind of mesh were you looking for?

Simon

gsbhatia89 June 11, 2010 08:24

hey,

I made this model in ansys. Well if you import it using workbench readers..it doesnt really do a great job of importing the curves and only some bit of the geometry is converted into ICEM.

With the ansys mesher, I get a decent mesh of 50k elements which I was told is not enough at all to analyse this sort of simulation. Also I had posted on the CFX part of the forum. I tried simulating with the ansys mesh in CFX, the problem is ..the multicomponent species mixing at high turbulence is not happening correctly...http://img526.imageshack.us/i/covolu...ion091102.png/

In conditions of high turbulence it should behave more like chaotic mixing but this seems like just laminar flow... =/

Anyway to give you a background again, the syngas(CO/h2) is injected through that cross geometry while air passes by it..and the aim is analyse the mixing..

PSYMN June 11, 2010 08:34

Give it another try.
 
It should import from DM (or directly via the workbench readers) perfectly. Maybe I can get this model from you and send it to development for testing.

My guess is you just need to refine your mesh in Workbench. You probably also need to refine in the volume. (with a body of influence). Is your physics set to CFD? Did you turn on the sizing function? Did you increase the relevance?

You could get a really nice Hexa Mesh in ICEM CFD (if that is what you are after, I could show you how), but if you just want a tetra prism mesh, I would suggest you try again in ANSYS Meshing. You just need to control the mesh size a bit better.

Simon

gsbhatia89 June 11, 2010 09:00

thank you very much for your help..

I want to learn more about how to work on ICEM and also the ansys mesher so I wish to try it myself first... :)

Could you tell me more about the hexa meshing in ICEM...if it doesnt take a month to do it..I might as well go for it!

http://img265.imageshack.us/i/importedgeometry.png/

this is the imported geometry (and the mesh with it...not shown) ...I beleive I need to create topology or work with surface creation etc.. You could elaborate from here...

....
Also I havent played around with volume meshing in the ansys mesher as of yet...And I will look into the advanced sizing as well..and the relevance...

Regards
Gagan

gsbhatia89 June 14, 2010 08:24

.....

Bump!...


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