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March 30, 2013, 10:30 |
Normal Extrusion of unstructured domains
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#1 |
Senior Member
Ali
Join Date: Jan 2012
Location: Pakistan
Posts: 134
Rep Power: 16 |
Hi,
I have tried to extrude --> normal unstructured domains, it looks like as shown in attached pic. There are some kinks, how they can be removed because they create problems for outer block skewness? In attached image only inner extruded block is shown. One thing more how to check orthogonal quality of blocks in Pointwise.
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Best Regards Ali |
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April 2, 2013, 08:45 |
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#2 | |
Senior Member
Chris Sideroff
Join Date: Mar 2009
Location: Ottawa, ON, CAN
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In general, you can't remove them. They're a result of the extrusion algorithm. Honestly, the wiggles don't look that bad (at least the portion in your picture). They usually get more pronounced they further the extrusion, so you might consider extruding one less layer and there may be less wiggles in it.
There are more advanced parameters you could modify that may (or may not) help. You can enable Triangle Aspect under Smoothing (this should help with the wiggles). If you don't like what Triangle Aspect does, you may consider increasing the number of Step Size and Direction iterations. I've never seen much change by modifying these but it's worth a shot. What do you do you mean by "orthogonal quality"? If the orthogonal you're referring to is OpenFOAM's, there is no equivalent metric in Pointwise. Quote:
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April 2, 2013, 14:23 |
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#3 |
Senior Member
Ali
Join Date: Jan 2012
Location: Pakistan
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I am referring to Fluent. Fluent always checks orthogonal quality.
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April 2, 2013, 18:25 |
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#4 |
Senior Member
Chris Sideroff
Join Date: Mar 2009
Location: Ottawa, ON, CAN
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I was testing out the different parameters in the prism extrusion and found out that turning off the Orthonormal smoothing parameter will pretty much eliminate the wiggles in the extrusion front.
So leave all other parameters default and uncheck Orthonormal smoothing. Fluent's orthogonal quality metric is pretty much the same as OpenFOAM's meaning there is no quality metric in Pointwise that corresponds to it. -Chris |
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April 3, 2013, 03:25 |
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#5 |
New Member
nikos
Join Date: Jun 2010
Location: Greece
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In fluent use mesh-> info -> quality then mesh-> smooth/swap if repair needed.
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April 3, 2013, 09:37 |
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#6 | |
Senior Member
Ali
Join Date: Jan 2012
Location: Pakistan
Posts: 134
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Quote:
So, I concluded: Check/Uncheck: Feature Check: Orthonormal smoothing Check: Triangle Aspect
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April 8, 2013, 09:56 |
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#7 |
Senior Member
John Chawner
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
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There isn't an explicit orthogonality check except for right at the wall. Otherwise you can use either Equi-volume or Equi-angle skewness (these are very similar to Fluent's measures) or minimum/maximum included angles.
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John Chawner / jrc@pointwise.com / www.pointwise.com Blog: http://blog.pointwise.com/ on Twitter: @jchawner |
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