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-   -   Blocking strategy (http://www.cfd-online.com/Forums/ansys-meshing/66334-blocking-strategy.html)

Twix July 12, 2009 15:33

Blocking strategy
 
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Hi

What will be the best blocking strategy ( 2D only for fluid around the blade) for this geometry.

Thanks in advance.

PSYMN July 13, 2009 20:59

Example...
 
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Try something like this...

Basically, you use quarter ogrids on each end to shift the flow and give you more mesh where you need it, but things hook up periodic in the end...

You can do lots of similar things (I always start with a pen and paper). You could add more quarter ogrids to off set it more, or you could do an lgrid which puts more mesh out the back...

I am interested in what other good layouts our clever colleagues and post here.

Twix July 14, 2009 18:46

1 Attachment(s)
Hi,

thanks for quick reply. I made this blocking but I have another question. When I change edge parameter on one edge it influent to other edges and I can’t set proper number of nodes. Why?:confused:

Twix July 15, 2009 08:46

Hi, it’s me again I know why those edges was dependent and I couldn’t set proper number of nodes. I don’t delete block permanently.

Regards

PSYMN July 15, 2009 09:47

Have Fun.
 
Yea, if you don't delete that inner block permanently, things will propagate across...

Have fun.

PSYMN July 15, 2009 09:49

Tip Gaps
 
On the other hand, if you need to model the tip gap, you will need to use a blocking straegy that does not rely on deleting that inner block. The quarter ogrid trick I showed can be slightly modified to work without deleting your inner block.

Twix July 15, 2009 18:26

Hi I have another problem, I don’t know how to fix penetrating elements. For mesh consist of 600 000 elements I have about 5000 penetrating elements on boundary fluid-solid . I think that is the reason why I can’t decrease y+ below 1.

Thanks in advance

PSYMN July 16, 2009 13:50

scan planes to the rescue
 
This could be due to a bunch of things, most likely projection (association) issues. View some cross sections (scan planes) across the area where the penetration;) is happening and try to figure out what is not projecting correctly...

Twix July 19, 2009 16:18

Hi.

You was right Simon it was association problem, I don’t associate some curves. Now I don’t have penetrating elements and y+ is bellow 1.

Thank You very much.

Regards

Saima June 25, 2010 17:55

Hello,

Do you guys please let me know how you creat this outer boundary of blade is there any rule? if yes pls let me know?

Secondly how u did meshing in ICEM CFD i did tutorial which is available on you tube but still i am not getting how i can do for blade?

If you have some documentation on it pls send me on samahmedpk2000@hotmail.com

Thank you and Regards,

t_shirt June 27, 2010 13:07

2D NASA Rotor 67 Blade prifile blocking
 
1 Attachment(s)
Hi,

Could ypu please let me know how can i creat blocking for this profile?

Pic is atatched here.



Quote:

Originally Posted by PSYMN (Post 222782)
On the other hand, if you need to model the tip gap, you will need to use a blocking straegy that does not rely on deleting that inner block. The quarter ogrid trick I showed can be slightly modified to work without deleting your inner block.


Twix June 28, 2010 12:09

Hi,
Watch this tutorial, it should help.
http://www.youtube.com/watch?v=tYrbS...eature=related

Regards


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