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Boolean Difference of Solids
Posted Sep 2, 2011, 4:34 p.m. EDT Heat Transfer & Phase Change, Geometry 4 Replies
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I'm attempting to model Joule heating in a metallic object immersed in a saline slurry. I've created the slurry object and assigned material properties to it. I've also imported a CAD model of the metallic object (an hip prosthesis).
I'm assuming that I must do some kind of Boolean difference of the object and the liquid slurry before proceeding. Is this correct, or does COMSOL somewhow figure this out on its own?
I'm assuming that I must do some kind of Boolean difference of the object and the liquid slurry before proceeding. Is this correct, or does COMSOL somewhow figure this out on its own?
4 Replies Last Post Sep 7, 2011, 10:54 a.m. EDT
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Posted:
1 decade ago
Hi
when you leave the geoemtry node, COMSOL does "ana analyse" of the geoemtry and transform the "objects" (what I call volumes faces, lines and points" and into "entities" (Dmains, boundaries, edges, points)
If you work in "union mode" (finish node) then COMSOl will make two domains, your metallic part and the surrounding volume (difference of overlapping volumes)
In "assembly" mode (nothing to do with a CAD assembly be aware ;) the volumes will overlap, then you must do the union, difference etc yourself before leaving the Geomtry node
This is very important concept and methodology steps of COMSOL to understand, as COMSOl differs from other "older" FEM tools here.
The "physics" is inked to the denumered "Entities" and NOT to the "objects, NOR directly to the mesh (of the entities)
--
Good luck
Ivar
when you leave the geoemtry node, COMSOL does "ana analyse" of the geoemtry and transform the "objects" (what I call volumes faces, lines and points" and into "entities" (Dmains, boundaries, edges, points)
If you work in "union mode" (finish node) then COMSOl will make two domains, your metallic part and the surrounding volume (difference of overlapping volumes)
In "assembly" mode (nothing to do with a CAD assembly be aware ;) the volumes will overlap, then you must do the union, difference etc yourself before leaving the Geomtry node
This is very important concept and methodology steps of COMSOL to understand, as COMSOl differs from other "older" FEM tools here.
The "physics" is inked to the denumered "Entities" and NOT to the "objects, NOR directly to the mesh (of the entities)
--
Good luck
Ivar
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Posted:
1 decade ago
Thank you for the prompts response! To be clear, when you speak of working in "Union mode", what exactly does that mean? Do I performa boolean union of the part and the slurry?
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Posted:
1 decade ago
Hi
check the doc aboit the "geoemtry". when you leave the geometry node you have two distinct options in the "Finish" node (V4): its "union" or "assembly"
check the forum too (search) there are several discussions around this important feature of COMSOL
--
Good luck
Ivar
check the doc aboit the "geoemtry". when you leave the geometry node you have two distinct options in the "Finish" node (V4): its "union" or "assembly"
check the forum too (search) there are several discussions around this important feature of COMSOL
--
Good luck
Ivar
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Posted:
1 decade ago
Thank you again.
I discovered this after posting my question to you yesterday and was able to make more progress in the modeling. I'm now dealing with meshing issues in the hip implant model imported from another CAD program, but this is another problem altogether!
Cheers,
David
I discovered this after posting my question to you yesterday and was able to make more progress in the modeling. I'm now dealing with meshing issues in the hip implant model imported from another CAD program, but this is another problem altogether!
Cheers,
David