CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   ANSYS Meshing & Geometry (http://www.cfd-online.com/Forums/ansys-meshing/)
-   -   [ICEM] Blocking Strategy And Quality (http://www.cfd-online.com/Forums/ansys-meshing/116939-blocking-strategy-quality.html)

FJSJ April 29, 2013 04:55

Blocking Strategy And Quality
 
5 Attachment(s)
Hi guys,

I want to ask you for a doubt about blocks and quality. In the first three pictures you can see the domain, mesh quality and some blocks. Then in the 3 last, you can see a very similar example (the same as before but... with the tip). But as you can see the quality is very bad. So.. my question is..is it a normal behaviour? I mean, Iīve placed all the vertices in the same location that example before where I got a good quality . I think that, maybe, this can be for the tip blocking that is new in the second example and can influence in them but Iīm not sure.

FJSJ April 29, 2013 04:56

1 Attachment(s)
Here the bad elements in the second example

BrolY April 29, 2013 05:03

Those are not bad elements, they are inverted elements ! Something is wrong with your blocking.
Share your *.tin and *.blk files so we can have a look.

FJSJ April 29, 2013 05:06

Inverted elements?? I have exactly the same blocking in the first example and I donīt have inverted elements. That is my question. I canīt understand why in one yes and other not.

BrolY April 29, 2013 05:25

But your geometry is not the same than in the first example ?
That's why there are inverted elements !

FJSJ April 29, 2013 05:44

I have the same geometry and blocking in both examples. Thatīs the weird...

BrolY April 29, 2013 05:47

Quote:

Originally Posted by FJSJ (Post 423795)
Hi guys,

I want to ask you for a doubt about blocks and quality. In the first three pictures you can see the domain, mesh quality and some blocks. Then in the 3 last, you can see a very similar example (the same as before but... with the tip). But as you can see the quality is very bad. So.. my question is..is it a normal behaviour? I mean, Iīve placed all the vertices in the same location that example before where I got a good quality . I think that, maybe, this can be for the tip blocking that is new in the second example and can influence in them but Iīm not sure.

You said "the same as before but ... with the tip". Maybe your blocking doesn't cover that, and that's why it created inverted elements.
Can you share both projects ?

FJSJ April 29, 2013 06:05

2 Attachment(s)
Maybe I explained wrong. I said "the same as before.." but refered at the geometry plus the tip blade. But yes, the blocking in the second example covers the tip. Look at this pictures.

diamondx April 29, 2013 08:51

it should be a minor problem with your blocking , run scan mesh and scan planes for investigation

FJSJ April 29, 2013 11:21

3 Attachment(s)
Itīs possible that It can be because ICEM confused parts? As you can see, I have a color blade part in a part where doesnīt have to... Diamondx told me once again, I have to specify more precisely... Can be for this reason?

diamondx April 29, 2013 11:32

the problem is related to association, you have to re-do your associations

FJSJ April 29, 2013 16:57

Ok. Iīll do again the associations. Iīll post tomorrow the result.

FJSJ April 29, 2013 17:02

1 Attachment(s)
However, the edge association picture of this examples is this. And I donīt see any wrong association. The problem is only in that area or.. can be in any of them?

FJSJ April 30, 2013 03:09

1 Attachment(s)
I think Iīve just resolved the problem about inverted cells. Iīve disassociated from geometry the edges but It didnīt work. So.. I used "Associate Edge to Surface" tool and problem was resolved. Here the picture. Thank you guys for the answers!

Although I would like to know why in the first example that I showed you I didn't have to use this tool and only I used "edge to curve associate". How does this behavior depend?

FJSJ April 30, 2013 11:21

4 Attachment(s)
I donīt know If I should create a new thread or not to ask for this topic... Iīve reduced highly bad elements but I have a bit of them. The problem is that bad elements are in a difficult area.. the tip. I got this approach few days ago. And now, I donīt know if I have to think in other approach or I can improve this one. Iīve seen Ralenīs approach but I decided to think in other because my domain is cylindrical. So... if anybody can provide some idea... this is welcome.
Thanks!


All times are GMT -4. The time now is 08:34.