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.
Volume integration
Posted 2009/11/23 17:06 GMT-5 3 Replies
Please login with a confirmed email address before reporting spam
Hi,
I am a COMSOL-beginner with what I guess might be a quite basic question. How (if possible) can I use Subdomain Integration Variables to get the volume of a subdomain in 2D axisymmetry mode. I need to set the density of a domain from the mass.
Thanks,
Johan
I am a COMSOL-beginner with what I guess might be a quite basic question. How (if possible) can I use Subdomain Integration Variables to get the volume of a subdomain in 2D axisymmetry mode. I need to set the density of a domain from the mass.
Thanks,
Johan
3 Replies Last Post 2009/12/18 6:14 GMT-5
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
An easy way would just be to define a subdomain integration coupling variable, name it "volume," and use 1 as your expression. Now your volume variable will contain the actual volume of that subdomain. I just tried this method for a simple rectangular geometry and it seems to work fine.
I should point out that I tried this with plane-strain mode, I'm not sure if you need to do anything differently for axisymmetric mode. But you can easily try it with simple geometry (that you know the answer to) and see if it works.
Good luck,
Mike
I should point out that I tried this with plane-strain mode, I'm not sure if you need to do anything differently for axisymmetric mode. But you can easily try it with simple geometry (that you know the answer to) and see if it works.
Good luck,
Mike
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
Hi
for axisymmetry you must use the "2*pi*r" with some care, it can be applied by a click for the BC (boundary conditions since 3.5) but must be applied by "hand" for boundary integration variables.
As suggested, by trying out on simple cases, and studying the units of COMSOL you can find easily the correct dimensions to apply (always check units 30 years later I start to understand that statement from my physics teacher ;)
COMSOL requires some "thinking" and pysics knowledge, but it has far more freedom than other "out-of the box" FEM programmes.
Good luck
Ivar
for axisymmetry you must use the "2*pi*r" with some care, it can be applied by a click for the BC (boundary conditions since 3.5) but must be applied by "hand" for boundary integration variables.
As suggested, by trying out on simple cases, and studying the units of COMSOL you can find easily the correct dimensions to apply (always check units 30 years later I start to understand that statement from my physics teacher ;)
COMSOL requires some "thinking" and pysics knowledge, but it has far more freedom than other "out-of the box" FEM programmes.
Good luck
Ivar
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
Thanks! Works great!
Regards,
Johan
Regards,
Johan