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Expression for mesh quality parameter

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I understand that the Comsol mesh quality parameter, represented by ale.qual or dg.qual, is some function of element aspect ratio that represents how stretched it is. However, I could not find the actual expression used to calculate it anywhere. Does anyone know what qual actually is?

6 Replies Last Post 3 juin 2015, 15:34 UTC−4
Bjorn Bretz COMSOL Employee

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Posted: 9 years ago 20 mai 2015, 03:33 UTC−4
Unfortunately, there is no simple expression for the mesh element quality that applies to each element type and dimension. The COMSOL Multiphysics documentation contains the following information on the mesh element quality.

"The absolute value of the mesh element quality is based on the ratios of the inscribed and circumscribed circles’ or spheres’ radii for the simplex corresponding to each corner of the element. If the simplex cannot be clearly determined (an apex of the pyramid, for example), the corresponding corner is excluded from the consideration. The absolute value is always between 0 and 1, where 0.0 represents a degenerated element and 1.0 represents the best possible element. A negative value means a contradiction to the COMSOL Multiphysics numbering convention for mesh element vertices (see Element Numbering Conventions), and the element is then referred to as an inverted element."

If you have more specific questions for your particular model I suggest that you contact COMSOL Support.

Sincerely,
Bjorn Bretz
COMSOL Development
Unfortunately, there is no simple expression for the mesh element quality that applies to each element type and dimension. The COMSOL Multiphysics documentation contains the following information on the mesh element quality. "The absolute value of the mesh element quality is based on the ratios of the inscribed and circumscribed circles’ or spheres’ radii for the simplex corresponding to each corner of the element. If the simplex cannot be clearly determined (an apex of the pyramid, for example), the corresponding corner is excluded from the consideration. The absolute value is always between 0 and 1, where 0.0 represents a degenerated element and 1.0 represents the best possible element. A negative value means a contradiction to the COMSOL Multiphysics numbering convention for mesh element vertices (see Element Numbering Conventions), and the element is then referred to as an inverted element." If you have more specific questions for your particular model I suggest that you contact COMSOL Support. Sincerely, Bjorn Bretz COMSOL Development

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Posted: 9 years ago 20 mai 2015, 09:33 UTC−4
Thanks, that description from the manual is sufficient for what I want to do.

Could you please point me to the section or page number in the manual where you got that from? I can't seem to find it in any of the documentation that's available when I click on the "help" icon in COMSOL 5.0 .
Thanks, that description from the manual is sufficient for what I want to do. Could you please point me to the section or page number in the manual where you got that from? I can't seem to find it in any of the documentation that's available when I click on the "help" icon in COMSOL 5.0 .

Bjorn Bretz COMSOL Employee

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Posted: 9 years ago 20 mai 2015, 09:53 UTC−4
In the documentation of the 5.1 version you can find this information under Programming Reference Manual > Mesh > Information and Statistics > Quality of Elements.

Sincerely,
Bjorn Bretz
In the documentation of the 5.1 version you can find this information under Programming Reference Manual > Mesh > Information and Statistics > Quality of Elements. Sincerely, Bjorn Bretz

Magnus Ringh COMSOL Employee

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Posted: 9 years ago 20 mai 2015, 09:53 UTC−4
Hi Aaron,

In COMSOL 5.0, you find it under Quality of Elements on page 252 of the COMSOL Multiphysics Programming Reference Manual.

Best regards,
Magnus Ringh, COMSOL
Hi Aaron, In COMSOL 5.0, you find it under Quality of Elements on page 252 of the COMSOL Multiphysics Programming Reference Manual. Best regards, Magnus Ringh, COMSOL

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Posted: 9 years ago 3 juin 2015, 15:26 UTC−4
Magnus,
Where do I find the COMSOL Multiphysics Programming Reference Manual?
Thanks
Magnus, Where do I find the COMSOL Multiphysics Programming Reference Manual? Thanks

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Posted: 9 years ago 3 juin 2015, 15:34 UTC−4
Never mind, I found it in my start menu!
Never mind, I found it in my start menu!

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