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Sphere inside a sphere
Posted Jun 16, 2010, 3:20 p.m. EDT 3 Replies
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First, I'm using COMSOL 4.0.
I'm trying to use COMSOL's geometry tool to create five spheres inside one another. The smallest sphere is the only real "sphere". The remaining spheres I created begin at the same place but have different diameters. What I was hoping for was the additional spheres to act as shells around one another. Is this the case?
I assumed when I selected materials from the property library that each sphere on the outside was acting as a shell, but you can't exactly tell while selecting the material. As COMSOL highlights each, it hides the shells inside of itself by shading red or blue.
I'm trying to use COMSOL's geometry tool to create five spheres inside one another. The smallest sphere is the only real "sphere". The remaining spheres I created begin at the same place but have different diameters. What I was hoping for was the additional spheres to act as shells around one another. Is this the case?
I assumed when I selected materials from the property library that each sphere on the outside was acting as a shell, but you can't exactly tell while selecting the material. As COMSOL highlights each, it hides the shells inside of itself by shading red or blue.
3 Replies Last Post Jun 18, 2010, 1:37 a.m. EDT
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Posted:
1 decade ago
Hi
if I understand you well you have several spheres around the same centre, or a layer of thick "onions" shells. At least that is also what I expect you will obtain, once "analysed" (after the "Finish" in V4).
To be able to select them easier, try the transparency option, or select them via their ID, then you can also "hide items" to select further "inside".
One thing to take care of: is the relative sizes (order of magnitudes of their respective radii) and to define how many elements you have/will get, just to be sure you stay within you RAM limits
Have fun Comsoling
Ivar
if I understand you well you have several spheres around the same centre, or a layer of thick "onions" shells. At least that is also what I expect you will obtain, once "analysed" (after the "Finish" in V4).
To be able to select them easier, try the transparency option, or select them via their ID, then you can also "hide items" to select further "inside".
One thing to take care of: is the relative sizes (order of magnitudes of their respective radii) and to define how many elements you have/will get, just to be sure you stay within you RAM limits
Have fun Comsoling
Ivar
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Posted:
1 decade ago
Thanks Ivar,
Yes I'm trying to make an onion type of problem. I am able to select the proper spheres to give them their respective properties (I used wireframe and/or ID).
The sizes of the layers are small, and relative to one another. I have around 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm radii layers.
So if I'm reading this correctly, ID1 (smallest sphere) will by the only "sphere" with properties, and the others will actually be shells of spheres. This is what I am hoping to make. This configuration is a type of nuclear fuel which has uranium dioxide in the center, and layers built up around this initial kernel. So hopefully I'll be able to model this fuel properly. Now I just need to create a material library entry for uranium oxide.
Thanks again.
Yes I'm trying to make an onion type of problem. I am able to select the proper spheres to give them their respective properties (I used wireframe and/or ID).
The sizes of the layers are small, and relative to one another. I have around 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm radii layers.
So if I'm reading this correctly, ID1 (smallest sphere) will by the only "sphere" with properties, and the others will actually be shells of spheres. This is what I am hoping to make. This configuration is a type of nuclear fuel which has uranium dioxide in the center, and layers built up around this initial kernel. So hopefully I'll be able to model this fuel properly. Now I just need to create a material library entry for uranium oxide.
Thanks again.
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Posted:
1 decade ago
Hi
when you say shell, you mean a 3D volume ? then the answer is yes,
not to confuse with the sphere surface (= surface shell). Both are possible but in 3D you have the volume = subdomains you must define too, in addition you can add surface properties (2D)
have fun Comsoling
Ivar
when you say shell, you mean a 3D volume ? then the answer is yes,
not to confuse with the sphere surface (= surface shell). Both are possible but in 3D you have the volume = subdomains you must define too, in addition you can add surface properties (2D)
have fun Comsoling
Ivar