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create separate subdomains

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hi
I want to know how I can create separate subdomains in my geometry.I made my 2D geometry by the help of vortexes and lines.but I dont have any subdomain in "subdomain setting".I selected the lines and click the 'union' buttton but it doesnt work.(I use COMSOL 3.5)
can anyone hep me with this?
I would be appreciate
maral

8 Replies Last Post 29.07.2010, 00:46 GMT-4

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Posted: 1 decade ago 26.07.2010, 09:44 GMT-4
Now, the only thing left is to convert them to solids (Conversions-> Convert to solid, in v4.0a).

Danial
Now, the only thing left is to convert them to solids (Conversions-> Convert to solid, in v4.0a). Danial

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Posted: 1 decade ago 26.07.2010, 10:01 GMT-4
hi Danial
thanx for reply
u mean there is no way in comsol 3.5?I dont have v4.I want to create 2 subdomain one for fluid and another for solid...
maral
hi Danial thanx for reply u mean there is no way in comsol 3.5?I dont have v4.I want to create 2 subdomain one for fluid and another for solid... maral

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Posted: 1 decade ago 26.07.2010, 10:50 GMT-4

hi Danial
thanx for reply
u mean there is no way in comsol 3.5?I dont have v4.I want to create 2 subdomain one for fluid and another for solid...
maral


Of course there is. Select the lines -- and hopefully they are already connected well -- and then select "coerce to solid" from the menu. I don't have 3.5 here so I can't exactly tell you where it was.
[QUOTE] hi Danial thanx for reply u mean there is no way in comsol 3.5?I dont have v4.I want to create 2 subdomain one for fluid and another for solid... maral [/QUOTE] Of course there is. Select the lines -- and hopefully they are already connected well -- and then select "coerce to solid" from the menu. I don't have 3.5 here so I can't exactly tell you where it was.

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Posted: 1 decade ago 26.07.2010, 13:12 GMT-4
Danial I did that,but it makes the geometry as a solid and some boundaries(the boundaries that are located between 2 subdomains) become deactivated..but i dont want it...I want to define boundary conditions for those deactivated boundaries...what should I do!?
thanx
maral
Danial I did that,but it makes the geometry as a solid and some boundaries(the boundaries that are located between 2 subdomains) become deactivated..but i dont want it...I want to define boundary conditions for those deactivated boundaries...what should I do!? thanx maral

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

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Posted: 1 decade ago 28.07.2010, 02:36 GMT-4
Hi
isnt it that by default in 3.5 the interiour boundaries are greyed out and you need to activate them specifically by selecting the "use interiour boundaries" to be able to apply anthing to them.

Further if you apply physics on interiour boundaries, you might need to use "assembly mode" for these boundaries (only) because then you might have noncontinuous fluxes and you need to access the "up" and "down" normals separately

--
Good luck
Ivar
Hi isnt it that by default in 3.5 the interiour boundaries are greyed out and you need to activate them specifically by selecting the "use interiour boundaries" to be able to apply anthing to them. Further if you apply physics on interiour boundaries, you might need to use "assembly mode" for these boundaries (only) because then you might have noncontinuous fluxes and you need to access the "up" and "down" normals separately -- Good luck Ivar

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Posted: 1 decade ago 28.07.2010, 10:08 GMT-4
Hi Ivar
very thanks for your reply...
Ivar would u please tell me how should I do that. My model is fluid-solid interaction and these interior boundaries are the boundaries between two subdomain where moving meshes(ALE method) is applied. I need to define these boundarie for each multiphysics(fluid,moving mesh and solid)..
whould u please tell me how I can use assembly mode?
regards
maral
Hi Ivar very thanks for your reply... Ivar would u please tell me how should I do that. My model is fluid-solid interaction and these interior boundaries are the boundaries between two subdomain where moving meshes(ALE method) is applied. I need to define these boundarie for each multiphysics(fluid,moving mesh and solid).. whould u please tell me how I can use assembly mode? regards maral

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

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Posted: 1 decade ago 28.07.2010, 10:41 GMT-4
Hi

in that case have you done the examples in the model library and those of the doc ? these gives good examples on how to deal with this, and the complex interactions are already partly set-up for you (at least in 3.5)

--
Good luck
Ivar
Hi in that case have you done the examples in the model library and those of the doc ? these gives good examples on how to deal with this, and the complex interactions are already partly set-up for you (at least in 3.5) -- Good luck Ivar

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Posted: 1 decade ago 29.07.2010, 00:46 GMT-4
thanx Ivar
it solved.
I selected each block and pressed the button "coerce to solid" and after that selected all and pressed "union" button.now I have all the boundaries.
regards
thanx Ivar it solved. I selected each block and pressed the button "coerce to solid" and after that selected all and pressed "union" button.now I have all the boundaries. regards

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