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Dirichlet Boundry layer

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I am trying to build a 2D model that simulate the distribution of electric field.So i am solving the LaplaceEquation with Dirichlet Boundary conditions.My problem that whenever i am trying to select the boundaries of my geometrical shape , it indicates that the boundaries are not applicable. So i would really appreciate if you can help me


Thanks in advance


3 Replies Last Post 2012/06/06 0:56 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2012/06/05 15:23 GMT-4
Hi

your geoemtry is a set of lines butare not closed to form a "solid geometric object", try a Convert to solid and select all and you will get a surface, this defines your 2D "domain" with corresponding "boundaries"

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Good luck
Ivar
Hi your geoemtry is a set of lines butare not closed to form a "solid geometric object", try a Convert to solid and select all and you will get a surface, this defines your 2D "domain" with corresponding "boundaries" -- Good luck Ivar

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Posted: 1 decade ago 2012/06/05 16:14 GMT-4
Thanks for your Reply

what i am trying to do exactly is to represent a symmetry of sphere for my domain.So my domain is air surrounded by boundary conditions which is steal in my case .So i do not understand you saying that i need to convert my geometry to solid object.So my voltage values across the boundary is zero except at point which represent a small semic-circle within my domain where my voltage value is 9000 Voltage.


Thanks
Thanks for your Reply what i am trying to do exactly is to represent a symmetry of sphere for my domain.So my domain is air surrounded by boundary conditions which is steal in my case .So i do not understand you saying that i need to convert my geometry to solid object.So my voltage values across the boundary is zero except at point which represent a small semic-circle within my domain where my voltage value is 9000 Voltage. Thanks

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

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Posted: 1 decade ago 2012/06/06 0:56 GMT-4
Hi

its part of the Geometry principles of COMSOL. for a 2D problem you need a closed defined 2D surface, you have only the lines around, so you need to groupe these into a surface, this is called "CONVERT TO SOLID" even if you are in 2D.

The naming convention is that in 3D a domain is a volume and a boundary is a surface, while in 2D a domain is a surface and a boundary is a line (check your doc, it's essential that you master well these conventions, it will save you days of misunderstanding and frustrating work

--
Good luck
Ivar
Hi its part of the Geometry principles of COMSOL. for a 2D problem you need a closed defined 2D surface, you have only the lines around, so you need to groupe these into a surface, this is called "CONVERT TO SOLID" even if you are in 2D. The naming convention is that in 3D a domain is a volume and a boundary is a surface, while in 2D a domain is a surface and a boundary is a line (check your doc, it's essential that you master well these conventions, it will save you days of misunderstanding and frustrating work -- Good luck Ivar

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