[ANSYS Meshing] Bad Mesh Quality on octogonal prism

Chris26 · November 22, 2017, 14:12

Hello everyone,

I am currently analyzing a tower with an unstructured mesh in ICEM CFD 17.2, but I also want to create a block-structured mesh to compare both results regarding the mesh-sensitivity. I am validating the tower with a wind tunnel experiment.

I was able to narrow my problem down to a simple octogonal prism. I am not able to create a structured mesh with just this rather simple geometry.

Pictures:
https://imgur.com/a/ghfOC

The reason why I chose to split the edges like that lies within the geometry that originally lies underneath it. With these splits I get no problems with the other geometry underneath it. The only bad elements lie right above the prism as seen in the last picture.

Thanks for any help on this!

Gweher · November 23, 2017, 04:58

Hi Christian,

The bad quality elements come from your inner blocking. I would go for an Ogrid type approach, or switch to a Y-block for the 4 problematic blocks.

Have fun

November 22, 2017, 14:12	Bad Mesh Quality on octogonal prism	#1
Chris26 New Member Christian B. Join Date: Nov 2017 Posts: 1 Rep Power: 0	Hello everyone, I am currently analyzing a tower with an unstructured mesh in ICEM CFD 17.2, but I also want to create a block-structured mesh to compare both results regarding the mesh-sensitivity. I am validating the tower with a wind tunnel experiment. I was able to narrow my problem down to a simple octogonal prism. I am not able to create a structured mesh with just this rather simple geometry. Pictures: https://imgur.com/a/ghfOC The reason why I chose to split the edges like that lies within the geometry that originally lies underneath it. With these splits I get no problems with the other geometry underneath it. The only bad elements lie right above the prism as seen in the last picture. Thanks for any help on this!

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November 23, 2017, 04:58		#2
Gweher Senior Member Gwenael H. Join Date: Mar 2011 Location: Switzerland Posts: 392 Rep Power: 20	Hi Christian, The bad quality elements come from your inner blocking. I would go for an Ogrid type approach, or switch to a Y-block for the 4 problematic blocks. Have fun