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Building a domain within a Difference

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Hi

I am trying to model thermocouples within a geometry, I have used the "Difference" tool to create holes within my geometry, however, the heat diffusion in the solid has "kinks" in the line graph at these points. I feel these should not occur, and that the temperature curve should be continuous, I am assuming that these are here because I have not specified what these holes in the geometry are, as the heat flow is hindered.

Essentially, what I am stuck with, is how to "fit"thermocouples into these holes, and treat them as a domain made of a solid material?

Many thanks for the help!!

R

1 Reply Last Post 28 févr. 2012, 01:12 UTC−5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 28 févr. 2012, 01:12 UTC−5
Hi

you do not always need to take the differences. If you overlap objects in 2D (or 3D) geometry, then when you pass the Finish line of the geometry your differences will be made and the object transformed into numbered and unique entities (domains, boundaries edges points), then you can define the different materials per domains.

Often one forget that the heat flux (derivative of the temperature = dependent variable) requires a fine mesh, particularly in transient mode and where the section are restricted. I often use boundary mesh in HT and transient to improve the transition between mateerails with large differences in heat diffusivity (just as I do in classical diffusion for materials with large difference in Diffusivity)

--
Good luck
Ivar
Hi you do not always need to take the differences. If you overlap objects in 2D (or 3D) geometry, then when you pass the Finish line of the geometry your differences will be made and the object transformed into numbered and unique entities (domains, boundaries edges points), then you can define the different materials per domains. Often one forget that the heat flux (derivative of the temperature = dependent variable) requires a fine mesh, particularly in transient mode and where the section are restricted. I often use boundary mesh in HT and transient to improve the transition between mateerails with large differences in heat diffusivity (just as I do in classical diffusion for materials with large difference in Diffusivity) -- Good luck Ivar

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