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Volume Integration of revolution 2D

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2D axisymmetry
The geometry is a rectangle
Right-click Data sets, and choose Revolution 2D, set revolution angle as 360 deg
Right-click Derived values, and choose Volume Integration, set Expression as 1, then Click the button " = "
It was expected to obtain the volume, but an error happened "Cannot evaluate expression"
What's the problem?

7 Replies Last Post Apr 8, 2011, 8:12 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Oct 22, 2010, 3:46 p.m. EDT
Hi

if you are in 2D axi how can you get a volume ? are you in 3.5 ? then be sure you integrate on the right "volume"/geoemtry

--
Good luck
Ivar
Hi if you are in 2D axi how can you get a volume ? are you in 3.5 ? then be sure you integrate on the right "volume"/geoemtry -- Good luck Ivar

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Posted: 1 decade ago Oct 22, 2010, 8:50 p.m. EDT

Hi

if you are in 2D axi how can you get a volume ? are you in 3.5 ? then be sure you integrate on the right "volume"/geoemtry

--
Good luck
Ivar

My comsol version is 4.0
In postprocessing, i.e. the Results, I right-click Data sets, and choose Revolution 2D, then set the parameters in the Revolution 2D interface, Axis entry method = two points, Revolution angle = 360 deg, then I can get the volume (a cylinder)
[QUOTE] Hi if you are in 2D axi how can you get a volume ? are you in 3.5 ? then be sure you integrate on the right "volume"/geoemtry -- Good luck Ivar [/QUOTE] My comsol version is 4.0 In postprocessing, i.e. the Results, I right-click Data sets, and choose Revolution 2D, then set the parameters in the Revolution 2D interface, Axis entry method = two points, Revolution angle = 360 deg, then I can get the volume (a cylinder)

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Oct 23, 2010, 4:06 a.m. EDT
Hi

OK now I understand your are in the Postprocessing, I was searching in the "Geometry" as there too you can generate "revolved" geoemtry in 3D from 2D.

I will have to try it out, I have only used this function so far for visualisation. Normally you integrate a volume fromn 2D axi with a 2*pi*r the "loop length", but there is also the click box in some of the advanced features (not everywhere though) and between 3.5 and 4 there is a 2*pi change. I never remember so I always check by hand the eqautions behind and a simple numerical test, to be sure ;)

--
Good luck
Ivar
Hi OK now I understand your are in the Postprocessing, I was searching in the "Geometry" as there too you can generate "revolved" geoemtry in 3D from 2D. I will have to try it out, I have only used this function so far for visualisation. Normally you integrate a volume fromn 2D axi with a 2*pi*r the "loop length", but there is also the click box in some of the advanced features (not everywhere though) and between 3.5 and 4 there is a 2*pi change. I never remember so I always check by hand the eqautions behind and a simple numerical test, to be sure ;) -- Good luck Ivar

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Posted: 1 decade ago Oct 23, 2010, 10:42 a.m. EDT

Hi

OK now I understand your are in the Postprocessing, I was searching in the "Geometry" as there too you can generate "revolved" geoemtry in 3D from 2D.

I will have to try it out, I have only used this function so far for visualisation. Normally you integrate a volume fromn 2D axi with a 2*pi*r the "loop length", but there is also the click box in some of the advanced features (not everywhere though) and between 3.5 and 4 there is a 2*pi change. I never remember so I always check by hand the eqautions behind and a simple numerical test, to be sure ;)

--
Good luck
Ivar


Thanks Ivar, but why I cannot get the volume using "Volume Integration"? However, there is a sentance "Make a volume integration of a 2D revolve" in COMSOL Multiphysics>Results analysis and plot features>Derived values and tables (the help document)
[QUOTE] Hi OK now I understand your are in the Postprocessing, I was searching in the "Geometry" as there too you can generate "revolved" geoemtry in 3D from 2D. I will have to try it out, I have only used this function so far for visualisation. Normally you integrate a volume fromn 2D axi with a 2*pi*r the "loop length", but there is also the click box in some of the advanced features (not everywhere though) and between 3.5 and 4 there is a 2*pi change. I never remember so I always check by hand the eqautions behind and a simple numerical test, to be sure ;) -- Good luck Ivar [/QUOTE] Thanks Ivar, but why I cannot get the volume using "Volume Integration"? However, there is a sentance "Make a volume integration of a 2D revolve" in COMSOL Multiphysics>Results analysis and plot features>Derived values and tables (the help document)

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Oct 24, 2010, 2:36 p.m. EDT
Hi

well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table

--
Good luck
Ivar
Hi well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table -- Good luck Ivar


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Posted: 1 decade ago Oct 24, 2010, 7:43 p.m. EDT

Hi

well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table

--
Good luck
Ivar


Thank you very much, Ivar! But when I try to open the file VolInt1.mph, an error happened "File contains no model", I don't know why. My COMSOL is version 4.0.
[QUOTE] Hi well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table -- Good luck Ivar [/QUOTE] Thank you very much, Ivar! But when I try to open the file VolInt1.mph, an error happened "File contains no model", I don't know why. My COMSOL is version 4.0.

Tom Alexander Solgård

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Posted: 1 decade ago Apr 8, 2011, 8:12 a.m. EDT

Hi

well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table



Thanks for this demo-model, Ivar! It really helped me out.


--
MSc. Acoustics using COMSOL for modelling loudspeakers and room acoustics.
no.linkedin.com/pub/tom-alexander-solg%C3%A5rd/27/600/1b3
[QUOTE] Hi well I get a volume integrsation of the revolved volume by 1, and by the integration of 2*pi*r (via the volume integration check for 2D axi) and via the surface integration of "2*pi*r" the expression written out explicitely (see the table [/QUOTE] Thanks for this demo-model, Ivar! It really helped me out. -- MSc. Acoustics using COMSOL for modelling loudspeakers and room acoustics. http://no.linkedin.com/pub/tom-alexander-solg%C3%A5rd/27/600/1b3

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