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How to calculate a volume in a 2D-Axissymmetric modeling ?

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How can I correctly calculate the volume (changing in time) of a 3D Cylinder by means of a 2D-Axissymmetric modeling ?

A multiplication of the integral of the area of the 2D cross-section with Pi and with the instant maximum radius of the body might help. But even if this would work ... Then: How is the name of the appropriate "r" variable?


2 Replies Last Post 05.03.2014, 11:16 GMT-5

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Posted: 1 decade ago 05.03.2014, 09:52 GMT-5
Some helpful hint follows from
www.comsol.com/community/forums/general/thread/42791/
I have to check a checkbox, to make COMSOL realize, that I truely want the 3D volume, when I calculate 2D-axissymmetric model.

Something remains unclear:
When I use the Gauss-Formula for the volume, using the surface-integral
Volume = SurfaceIntegral(r*solid.nr)
I get twice the true volume as the result.

How do I have to modify this formula to calculate correct results?
Some helpful hint follows from http://www.comsol.com/community/forums/general/thread/42791/ I have to check a checkbox, to make COMSOL realize, that I truely want the 3D volume, when I calculate 2D-axissymmetric model. Something remains unclear: When I use the Gauss-Formula for the volume, using the surface-integral Volume = SurfaceIntegral(r*solid.nr) I get twice the true volume as the result. How do I have to modify this formula to calculate correct results?

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Posted: 1 decade ago 05.03.2014, 11:16 GMT-5
Abandoned in favour of a new thread
Abandoned in favour of a new thread

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