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Is there any relations between the "1D axial symmetry" and "spherical coordinate"

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Hello everyone. I am quite confused by the "1D axial symmetry geometry". To my understanding, "1D axial symmetry geometry" actually represents the spherical coordinate. For example, line in "1D axial symmetry geometry" represents arbitrary radius of a sphere , so if I can know the distribution along this line , I also know the distribution in the sphere.

I need to do some integration over a whole sphere domain rather than the line. so I define it like this: intop1(4*pi*r^2*f(r)). f(r) represents certain distribution along the line , intop1 is the symbol of line-integration. I can't get the right answer in this way.

I also noticed that the "revolution 1D" would result in a circle rather than a sphere, and the three vectors of this geometry are r, z ,phi ,which are identical with "2D axial symmetry". So I doubt by choosing "1D axial symmetry geometry", I can't extend the data from line to sphere?

Can you give me some advice ,please?


2 Replies Last Post 19.11.2012, 01:13 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 15.11.2012, 09:15 GMT-5
Hi

for me a 2D-axial is as a 2D-axial, but assume constant long Z so you reduce this vertical dimension and you remain with "r" alone.

Anyhow COSMOL is always working in 3D,
2D is simply 3D for any constant Z,
2D-Axi for any constant Phi,
1D-axi for any constant Phi and Z
and 0D is an ODE in time (only ?suddenly not sure anymore ;)

--
Good luck
Ivar
Hi for me a 2D-axial is as a 2D-axial, but assume constant long Z so you reduce this vertical dimension and you remain with "r" alone. Anyhow COSMOL is always working in 3D, 2D is simply 3D for any constant Z, 2D-Axi for any constant Phi, 1D-axi for any constant Phi and Z and 0D is an ODE in time (only ?suddenly not sure anymore ;) -- Good luck Ivar

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Posted: 1 decade ago 19.11.2012, 01:13 GMT-5
Thank you very much, Ivar.
I think I get your points , but I still don't know how to simplify a 3D spherical distribution to 1D modeling, what geometry system should I use. For example, the electric field stimulated by a point charge is spherical distributed in space, so I could just model an arbitrary radius of this sphere in 1D.
Could you please help me how to convert a spherical distribution model to a 1D model?
Thanks again and wish you a good day!
-------
Ning
Thank you very much, Ivar. I think I get your points , but I still don't know how to simplify a 3D spherical distribution to 1D modeling, what geometry system should I use. For example, the electric field stimulated by a point charge is spherical distributed in space, so I could just model an arbitrary radius of this sphere in 1D. Could you please help me how to convert a spherical distribution model to a 1D model? Thanks again and wish you a good day! ------- Ning

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