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AlphaDelta April 4, 2020 15:35

Remove invalid cells
 
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Hello,
I'm working on a three-blade wind turbine with Troposkien geometry.
After creating the mesh, I tried to do a mesh diagnostic.
Unfortunately I found 2 cells with face validity <95%.
Wanting to eliminate them, right clicking on the corresponding Region (called "rotor") I found the wording 'remove invalid cells' thinking to solve the problem.
After the removal procedure, I find in the Regions section a new region called "Cells deleted from Rotore" (as seen from the attached photo). Why? Did I really remove those cells?

In the photo you find the 'indicted' cells highlighted in purple.
I think the two invalid cells are positioned at the point where the external profile of the blade is tangent to the support above (I have three blades, but this only happens due to a problem).

Thanks a lot!

ping April 11, 2020 05:35

remove invalid cells is a absolute last ditch tool to hit a problem mesh with - a huge sledge hammer and so should be avoided unless you are confident that the hole left will have minimal effect on your analysis.
it puts the removed cells in a new region and you set this to have no physics or delete the region.
a much better solution for some bad cells is to try to determine why they were created and fix the underlying cad or refine the surface mesh locally somewhat - eg place of volume source around the area and apply it to both the surface and the volume mesher.
if you decided to use the wrapper due to poor cad then take a look at the wrapped surface in that area too.


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