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how to define a parameter with multiple variables ?
Posted 1 apr 2011, 22:42 GMT-4 Materials, Parameters, Variables, & Functions Version 4.0a 1 Reply
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hi
I met a thorny problem.
I'm modeling a heat transfer model with 2D axisymmetric. Thermal conductivity is a function with temperature and spaces. In the R and Z directions, the thermal conductivity is a linear function. And so with temperature.
I'm looking forward to your response. Thank you.
I met a thorny problem.
I'm modeling a heat transfer model with 2D axisymmetric. Thermal conductivity is a function with temperature and spaces. In the R and Z directions, the thermal conductivity is a linear function. And so with temperature.
I'm looking forward to your response. Thank you.
1 Reply Last Post 2 apr 2011, 05:23 GMT-4
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Posted:
1 decade ago
Dear Mr. Wang,
You can certainly implement such a parameter. If you click on the arrow next to the material, there will be a subnode called "Basic". If you right-click "Basic", then you get the option to add a function. Since it is a linear function in your case, an analytic function will do. Using an interpolation is also possible of course.
In Arguments, enter names for the arguments, for instance r1 and z1. Likewise, enter the expression, for instance r1*z1. By default, the function is called an1, but I can recommend to give it a different name like 'k', for thermal conductivity.
Then, in the material properties, called your function by entering k(r,z).
Important note: it is only when you call the function in the material property that the arguments will be defined! For instance, if you entered k(T,p) in the material property, then temperature and pressure would be used as arguments. The fact that you named them "r1" and "z1" in the function definitions is just that: names, no meaning (yet).
Hope that helps,
Ruud Börger
COMSOL BV
You can certainly implement such a parameter. If you click on the arrow next to the material, there will be a subnode called "Basic". If you right-click "Basic", then you get the option to add a function. Since it is a linear function in your case, an analytic function will do. Using an interpolation is also possible of course.
In Arguments, enter names for the arguments, for instance r1 and z1. Likewise, enter the expression, for instance r1*z1. By default, the function is called an1, but I can recommend to give it a different name like 'k', for thermal conductivity.
Then, in the material properties, called your function by entering k(r,z).
Important note: it is only when you call the function in the material property that the arguments will be defined! For instance, if you entered k(T,p) in the material property, then temperature and pressure would be used as arguments. The fact that you named them "r1" and "z1" in the function definitions is just that: names, no meaning (yet).
Hope that helps,
Ruud Börger
COMSOL BV