Floating point error compressible 2D diamond airfoil


#21

Hey Darren,

Your suggestion initially didn’t resolve the issue but it makes perfect sense due to how sharp the edge is. So I’ve continued to implement it as I finally found out what was causing the layering issue below.

This is the result!

Looks pretty good now. What do you think? Might need some more tuning to keep the layers evenly apart and maintain grid quality at the edge, but otherwise much better than the previous iteration.

So the change I made (after much guessing and reading) was to increase the “Max internal face skewness angle [°]”. Not only do the layers appear well now, it further confirms my initial guess that the quality controls are deleting the layers off at this area.

However, the minor catch is that now checkMesh does not deem the mesh as OK even with 0 illegal cells. So some further optimizing of the values for the “Max internal face skewness angle [°]” and maybe the “Max boundary face skewness angle [°]” will be needed along with maybe the layer controls, depending on geometry of course.

Ideally we get something like this in the below figure (in a hex mesh ofc) where the layers “lie on a straight horizontal line” rather than looking like they are converging to a single point like in the above figure.

I’ll go ahead and proceed with the 2D mesh generation now while I continue to optimize the layers. Will keep you posted.

Cheers.

Regards,
Barry

EDIT:

Hey Darren, I’m a little confused about 3D to 2D generation. I’ve downloaded your file posted and attempted to follow the steps in the video but I don’t seem to be able to find the extrudeMeshDict in the folder as you can see below. I’m pretty sure I missed something, so could you enlighten me on what to do?

Your download file

polyMesh
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Trisurface
image

I’ve also downloaded the refined mesh in this post, the files are as such.

image

image

polyMesh
image

No issues till the part where I had to edit the extrudeMeshDict.