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-   -   [ICEM] turbine blade meshing (http://www.cfd-online.com/Forums/ansys-meshing/92394-turbine-blade-meshing.html)

sk0pa September 13, 2011 09:12

turbine blade meshing
 
2 Attachment(s)
Hello, Iím trying to set up a 3d structed mesh in flat turbine blade cascade using blocking stratagy. Model consists of one blade and periodic bondaries. As a result I have mesh with hight skewness cells . Blocks structure presented on screenshot. Would you explane the stratagy of turbine blades meshing?

brunoc September 14, 2011 01:03

Hi skopa,

What you need here is a blocking strategy that is not so straightforward. Basically you'll have to create a block similar to the ones generated by Turbogrid, where periodic vertices belong to blocks originally from different axial positions. If you send us your .tin file maybe we can get you started.

Cheers

Ludvik September 14, 2011 04:15

see: http://www.youtube.com/user/ansysinc#p/u/29/tYrbScUH9RE
cca 3 minute

sk0pa September 16, 2011 06:33

2 Attachment(s)
Quote:

Originally Posted by brunoc (Post 324027)
Hi skopa,

What you need here is a blocking strategy that is not so straightforward. Basically you'll have to create a block similar to the ones generated by Turbogrid, where periodic vertices belong to blocks originally from different axial positions. If you send us your .tin file maybe we can get you started.

Cheers

Unfortunally I haven't turbogrid license. But all exaples of turbogrid blocking structure were applied to geometry with less angle of flow turn then in my case. I tried to split block structure as shown in the picture, but it doesn't solve my problem. There are hight skewness cells near the trailing age. And I tried smoothing and it doesn't solve my problem.

sk0pa September 16, 2011 09:46

turbine blade meshing
 
link with geometry
http://www.4shared.com/file/g_xokif3/Mesh.html

brunoc September 16, 2011 11:22

Hi skopa,

There seems to be something wrong with your geometry, since both the hub and the shroud have the same area. This means that it has and infinite radius. If you're working with a turbine, that's impossible.

Anyway, here's a shot at the blocking of your geometry. Correct anything you like and set the bunching.
http://www.4shared.com/file/rhaO7DBt/project1.html

BTW, it just struck me that you can generate this mesh a lot easier if you just create it inside ANSYS Meshing using either a sweeping or a Multizone method. You'll get something similar to what I did without almost any effort.

sk0pa September 19, 2011 06:14

turbine blade meshing
 
Quote:

Originally Posted by brunoc (Post 324418)
Hi skopa,

There seems to be something wrong with your geometry, since both the hub and the shroud have the same area. This means that it has and infinite radius. If you're working with a turbine, that's impossible.

Anyway, here's a shot at the blocking of your geometry. Correct anything you like and set the bunching.
http://www.4shared.com/file/rhaO7DBt/project1.html

BTW, it just struck me that you can generate this mesh a lot easier if you just create it inside ANSYS Meshing using either a sweeping or a Multizone method. You'll get something similar to what I did without almost any effort.

Thank you for mesh, but I can't understand some operations which you did. Could you send me script file? the hub and the shroud have infinite radius, because this model is for aerodynamic tunnel.

brunoc September 19, 2011 19:17

Sorry, but I don't have a script file. What didn't you understand?

nabilhaneef October 24, 2011 15:26

Cfd on ngv cascade
 
Hello,

I am a new user for the CFD tool and i am doing a current project work on the cascade arrangement of the NGV.. THe problem is that i have set my model in ICEM meshing tool but i am stuck with the grid generation.. Can any one guide me how do i generate the grid and what are the methods involved... its the same form of grid as posted earlier.. How is the grid dimensions set.
Also i am stuck with the validation part of the CFD.. Can anyone help me with these details too.. SO that i can validate my CFD results..

Far October 25, 2011 10:59

4 Attachment(s)
awesome topology, I really like it. How did you make it?

Far November 10, 2011 05:59

1 Attachment(s)
@ sk0pa

I did mesh on your geometry, if you need any guidance or script file I am more than happy to help you

hadikhayyamian March 30, 2012 23:51

Hi Far;
can I see the blocking of the above 2D mesh, please?

hadikhayyamian March 30, 2012 23:53

Hi SK0Pa,
I think in your figure, the leading edge is not associated with its corresponding block edge.http://www.cfd-online.com/Forums/att...shing-mesh.jpg

Far April 5, 2012 09:43

Hi

I do not have the blk. I can reproduce the topology for you.

ticsh April 17, 2012 08:17

hi Far!
could you share the block file with geometry plz )

Far April 17, 2012 08:30

Just give me some time to reproduce the blocking.

ticsh April 25, 2012 07:49

What are the main criteria of mesh quality in ICEM CFD for such objects? Are they differ for different solvers?

brunoc April 25, 2012 08:01

Quote:

Originally Posted by ticsh (Post 356859)
What are the main criteria of mesh quality in ICEM CFD for such objects? Are they differ for different solvers?

Yes, each solver has it's strenghts and depends on certain quality metrics. But as a general rule for CFD solvers you should look at face angle (angle between two faces or edges), aspect ratio and volume change. On most cases, checking the skewness alone will give you an idea of your mesh quality.

venkat_aero2007 August 9, 2013 06:54

Propeller blade- J type blocking
 
4 Attachment(s)
Hi
I am trying to mesh a propeller blade. I tried to mesh the propeller blade just like the wing. The propeller geometry is shown in the figure 1. Firstly I created a block and made it periodic. Then I made a two horizontal split (along y-axis), one in the front of the blade and other behind the blade. And I also made two vertical split (along x-axis), one in the suction side and other in the pressure side. Then I inserted a O-block and merged the vertex in the trailing edge and converted into C-block. Then I associated the edges to the curves of the airfoil section of the propeller blade. Figure 2 shows the block details. I made several split along the span of the propeller blade and associated the edges as I said previously. I got a nice mesh with good quality.

Actually I want to do optimization so I am going to automatize the meshing process. When I change the twist angle along the span of the blade, I get high skew cells near the blade region as shown in the figure 3. I am going to change the twist angle continuously during the optimization process. So this blocking strategy doesn't work.

I heard of shifted periodic blocking strategy will fine for the highly twisted blade. I have seen several posts about the shifted periodic block but I really donít know how to do it and I donít know how I can apply the shifted periodic for my propeller blade.

I need a blocking like figure 4. But I dont know how to get that. Please help me to construct such blocking strategy. I have attached the tin and block file. Please help me.

https://www.dropbox.com/sh/jkl3dqoaf...ont_domain.tin
https://www.dropbox.com/sh/jkl3dqoaf...ont_domain.blk

https://www.dropbox.com/sh/jkl3dqoaf...ont_domain.prj


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