Difference between Aspect Ratio and Skewness

- June 17, 2019 at 9:21 am
  
  xavierBAM
  Subscriber
  
  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
- June 17, 2019 at 10:48 am
  
  Rob
  Forum Moderator
  
  They're different ways of working out mesh quality and (generally) serve to check for different problems. What do you think each means?
- June 17, 2019 at 12:05 pm
  
  xavierBAM
  Subscriber
  
  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?
- June 17, 2019 at 12:39 pm
  
  Rob
  Forum Moderator
  
  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.