Learning Forum

[xavierBAM]

Hello, I was doing some meshing quality control and, when I got to understand what Aspect Ratio and Skewness was, I could get what's the difference between these two parameters. Could anybody explain? Thanks

[Rob]

They're different ways of working out mesh quality and (generally) serve to check for different problems. What do you think each means? 

[xavierBAM]

It just looks like they are very similar in the way they value the quality of the mesh. How similar to a perfect triangle and how similar the lengths of the sides are looks too much a like for me. When would you use each one of them?

[Rob]

Ah, OK, you've not quite picked up the maths. 

 

Skew is a function of the ratio internal angles against the "perfect angle". 

Aspect ratio is a ratio of the edge lengths. 

 

Look in the help documentation under Meshing and there should be images explaining it.  For tri/tet elements a high aspect ratio means high skew: for a quad/hex element high aspect ratio can still have zero skew. Sketch the two shapes (triangle & square) and stretch them then compare to the documentation.