Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Problems with geometry quality

Please login with a confirmed email address before reporting spam

Hello. First of all i am fairly new comsol user. Currently i am studying heating of fused silica fibers (https://en.wikipedia.org/wiki/Optical_fiber) for purposes of laser applications. Typical optical fiber is very thin cylinder (diameter is 125 um) with big length (1 m and much more). So this is the place where the problem appears. I draw a fiber with lenght of 1.5 mm and diameter of 125 um and comsol manage it very good (see two files "Length_1500um_General View.jpg" and "Length_1500um_Transverse View.jpg"). But fiber with length of 1 m looks very low poly and modeling heating in such geometry is worthless ("Length_1m_General View.jpg" and "Length_1m_Transverse View.jpg"). Is there any mean to make comsol maintain quality in this situation?



4 Replies Last Post 01.09.2019, 05:20 GMT-4
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 28.08.2019, 17:17 GMT-4

This is a rendering effect due to the high aspect ratio, and it has been discussed before in this Discussion Forum, see e.g. https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z .

The cross section of your geometric object is still a circle even if it does not look that way on screen. This will become obvious when you mesh one of the end surfaces of your fiber.

Best regards,

Jeff

-------------------
Jeff Hiller
This is a rendering effect due to the high aspect ratio, and it has been discussed before in this Discussion Forum, see e.g. https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z . The cross section of your geometric object is still a circle even if it does not look that way on screen. This will become obvious when you mesh one of the end surfaces of your fiber. Best regards, Jeff

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 29.08.2019, 14:53 GMT-4

This is a rendering effect due to the high aspect ratio, and it has been discussed before in this Discussion Forum, see e.g. https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z .

The cross section of your geometric object is still a circle even if it does not look that way on screen. This will become obvious when you mesh one of the end surfaces of your fiber.

Best regards,

Jeff

Thank you. I will look through your link.

>This is a rendering effect due to the high aspect ratio, and it has been discussed before in this Discussion Forum, see e.g. https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z . > >The cross section of your geometric object is still a circle even if it does not look that way on screen. This will become obvious when you mesh one of the end surfaces of your fiber. > >Best regards, > >Jeff Thank you. I will look through your link.

Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 29.08.2019, 16:11 GMT-4
Updated: 5 years ago 29.08.2019, 16:11 GMT-4

Here is a better link on the same topic: https://www.comsol.com/forum/thread/36108/geometry-of-a-cylinder?last=2013-07-04T06:45:03Z

Jeff

-------------------
Jeff Hiller
Here is a better link on the same topic: https://www.comsol.com/forum/thread/36108/geometry-of-a-cylinder?last=2013-07-04T06:45:03Z Jeff

Please login with a confirmed email address before reporting spam

Posted: 5 years ago 01.09.2019, 05:20 GMT-4

In topic (https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z ) Daniel Connelly suggest to use scaling rules to extend solution to longer lengths but i do not know how to do it. How to apply these rules in comsol?

In topic (https://www.comsol.com/forum/thread/77211/object-shape-changing-due-to-high-aspect-ratio?last=2015-05-19T18:02:19Z ) Daniel Connelly suggest to use scaling rules to extend solution to longer lengths but i do not know how to do it. How to apply these rules in comsol?

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.