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[ANSYS Meshing] Problem with O-grid in drill pipe

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Old   April 10, 2011, 08:55
Unhappy Problem with O-grid in drill pipe
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Hi guys,

I'm new in the forum and leraning CFD recently for my graduation project, so any advice would be very much appreciated.

I created a drill pipe for the fluid path to be stimulated by using O-grid. However when I have a look at angles of grids from quality controls they are not so good. May be I am doing wrong with O grid ? Do some one help me?
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Old   April 11, 2011, 20:26
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Your question doesn't have enough info for me to help you.

And remember, a pictures is worth a thousand words...
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Old   April 12, 2011, 07:13
Default Pipe
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Helo Simon.
First of all thank you for trying to help me. My aim to make better the angle distribution in the quality control the range og my angles is 45-88 degrees. Here I attached my pichture i Hope it will help you Pipe.jpg
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Old   April 12, 2011, 08:51
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Your angles look fine. Most solvers are happy if you can get it above 9 or 18 degrees. What is your worst angle? What is your worst aspect ratio?

However, you distributions could use some work.

Your radial edges need more nodes and they should be bunched toward the walls to better capture the boundary profile.

Alternatively, you could rescale your ogrid (rather than add more nodes). But you would still want to bunch toward the wall (growth rate of 1.2 or 1.5 away from the wall is common)

Ideally you would have a smooth transition across your model.

You could try running the Orthogonal hexahedral smoother if you wanted.
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Old   April 13, 2011, 05:48
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First of all thank you very much for helping
My smallest angle is 45 deg. so based on your reply it seems that OK.
I will try to change as you said , hope will work.
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Old   April 13, 2011, 08:43
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For your information, with the solver I'm using, if the smallest angle is superior to 18, it's good.
So with 45, you are more than good
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Old   May 4, 2011, 14:51
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hello
another way to improve the quality and appearance of the mesh is to reduce the size of Ogrid.

Blocking> Edit Block> Modify Ogrid

in Modify Ogrid> Method = Rescale Ogrid + Edge (is the radial O-grid selected edge) + Offset = 0.7
Attached Images
File Type: jpg ogrid.jpg (57.2 KB, 52 views)
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Old   May 5, 2011, 05:00
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Thanks German I will try
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Old   May 6, 2011, 11:51
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I recommend upload geometry files, blocks to try to help more.
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