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Anisotropic thermal conductivity with falloff question.
Posted Dec 5, 2015, 10:49 p.m. EST Heat Transfer, Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions, Structural Mechanics Version 5.1 2 Replies
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Hi all,
I'm trying to define a base material with isotropic thermal conductivity, but with a penetration zone along one axis where the k value falls off from the outer surface toward the center. Essentially, my material is soaked with another material of a higher k value that penetrates to a certain shell depth, falling off logarithmically as it goes deeper.
The way I was thinking of modelling this is defining the k value as anisotropic, with identical x,z scalar values and a changing y value based off of some log function.
I'm moderately new to COMSOL's more advanced features, and I'm not sure how to properly define this in the material properties.
Do you have any pointers/ tutorials/ advice?
Thanks in advance,
Evan
I'm trying to define a base material with isotropic thermal conductivity, but with a penetration zone along one axis where the k value falls off from the outer surface toward the center. Essentially, my material is soaked with another material of a higher k value that penetrates to a certain shell depth, falling off logarithmically as it goes deeper.
The way I was thinking of modelling this is defining the k value as anisotropic, with identical x,z scalar values and a changing y value based off of some log function.
I'm moderately new to COMSOL's more advanced features, and I'm not sure how to properly define this in the material properties.
Do you have any pointers/ tutorials/ advice?
Thanks in advance,
Evan
2 Replies Last Post Dec 7, 2015, 1:19 p.m. EST
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Posted:
9 years ago
Hi all,
I have found part of the solution to my problem in the Material Library User's Guide, but I need some help for the last bit.
* I figured out how to define the anisotropy of a material property in Materials->mat1->Basic->Output Properties.
* I found how to define a piecewise function for a property value in Materials->mat1->Basic->Piecewise.
* The Material Library User's Guide shows how to define density as a function of pressure and temperature.
Here's my new question:
How do I link spatial dimensions to piecewise functions?
In common language I want to say, "from 0m to 0.02m fall off from this k value to this k value".
I think the piecewise function is a good choice for this, but I don't know how to link spatial dimensions as arguments the same way T and p were linked in the example. Can I just use "x" as an argument, and then define the anisotropy to take care to limit solely to the axis of interest?
I have found part of the solution to my problem in the Material Library User's Guide, but I need some help for the last bit.
* I figured out how to define the anisotropy of a material property in Materials->mat1->Basic->Output Properties.
* I found how to define a piecewise function for a property value in Materials->mat1->Basic->Piecewise.
* The Material Library User's Guide shows how to define density as a function of pressure and temperature.
Here's my new question:
How do I link spatial dimensions to piecewise functions?
In common language I want to say, "from 0m to 0.02m fall off from this k value to this k value".
I think the piecewise function is a good choice for this, but I don't know how to link spatial dimensions as arguments the same way T and p were linked in the example. Can I just use "x" as an argument, and then define the anisotropy to take care to limit solely to the axis of interest?
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Posted:
9 years ago
Hello Evan,
Yes, x can be an argument to a piecewise function.
Best,
Jeff
Yes, x can be an argument to a piecewise function.
Best,
Jeff