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-   -   some problem on using turbogrid. (https://www.cfd-online.com/Forums/cfx/19904-some-problem-using-turbogrid.html)

Darcy Jiang September 20, 2003 09:10

some problem on using turbogrid.
 
Dear all Does somebody have some experience using TURBOGRID to construct grids(structured grid) arround a propeller on boat? I'm suffering the twisting and poor quality grids near the tip of propeller. Please give some subgestion to overcome the problem. Thx. Darcy

Martin Bowers October 5, 2003 18:43

Re: some problem on using turbogrid.
 
Either stop worrying about the quality of your mesh, which is usually a bad idea, or drop Turbogrid and use ICEMCFD HEXA.

Darcy Jiang October 6, 2003 09:28

Re: some problem on using turbogrid.
 
yeah, I think so. My co-worker used icem and constructed an unstructured grid with very good quality around the same geometry.

Martin Bowers October 8, 2003 15:37

Re: some problem on using turbogrid.
 
Turbogrid 1.x is good at creating a decent quality coarse mesh, but unfortunately it doesn't automatically give a high-quality fine grid, and it doesn't give the user enough control to manually make one. So you're stuck with some relatively low-quality fine grid, that takes EONS to generate.

There's Turbogrid 2.x, which is unstructured, but I haven't seen that yet so I can't offer an opinion. But I will say that unstructured and high-quality are two words for a mesh that don't often go together in my experience.

Robin October 10, 2003 12:43

Re: some problem on using turbogrid.
 
Hi Martin,

Perhaps you should try using TurboGrid 2 before commenting!

TurboGrid 2 is not unstructured! It generates high quality HEX grids which can be exported to CFX-5 (without structure) or CFX-TASCflow (block strucutured).

Regards, Robin

Bob Crad December 25, 2003 00:14

Geomerty and meshing with CFX
 
Dear Robin,

Merry Christmas to you!

I am in choosing a CFD package for a coming task where centripetal body forces will be considerable. To my knowledge, SSG model is the best one for rotating domains. That is, particularly, why, CFX seems to be suitable for me.

My concern is, however, the rumours are CFX geometry builder is not very strong and even unstable for real geometries (even if they are not extremely complicated).

Another issue is CFX Build generates only unstructured TET-grid (and prisms for boundary layer), I was told. Well, I would prefer to have a HEX generator.

There is a wide-spread opinion it is impractical to take GEOM-, MESH-, SOLVER and POST from different sources.

That is why, I would like to get you opinion on using BladeGen to make, say, a blade similar to that off a turbocharger blower wheel and then to use TurboGrid to create a good mesh.

Other words, what sort of pre-processor(s) CFX users employ in practice?

Thank you and cordial regards

Bob Crad

Glenn Horrocks January 4, 2004 17:23

Re: Geomerty and meshing with CFX
 
Hi Bob,

Robin has disappeared from this discussion group. A sad loss. You can find him on the CFX community discussion group if you want him specifically.

In the meantime I hope the rest of us can give you some useful comments. You can find my reply to your post in your other thread.

Glenn


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