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CTE Syntax error

Posted Jun 15, 2016, 12:59 p.m. EDT Heat Transfer & Phase Change, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.2 3 Replies

Nicholas Goldring Certified Consultant
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Hello everyone, I'm currently trying to define a function under the basic properties of the built-in silicon so that I can include a temperature-dependent coefficient of thermal expansion in my model. My expression for this CTE, which I gleaned from an old NIST paper is as follows:

-(0.687*10^(-6))+(5*10^(-6))*[(685/T)^2]*e^(685/T)/[exp^(685/T)-1]^2+(0.22*10^(-6))*[(T/395)-1]^2/[1+0.316*(T/395)]

I understand it's a little hairy with all of the coefficients but if anyone familiar with entering functions in to COMSOL might be able to point out something wrong with it, it would be greatly appreciated. I'm currently getting a syntax error. It is eqn (1) of this paper: www.nist.gov/data/PDFfiles/jpcrd220.pdf

Thanks as always.
3 Replies Last Post Jun 15, 2016, 1:31 p.m. EDT
Jeff Hiller COMSOL Employee

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Posted: 8 years ago Jun 15, 2016, 1:15 p.m. EDT
The problem is likely the square brackets: try replacing them with regular parentheses.
Square brackets are used in COMSOL to indicate units. That's just my .02[USD].
Best,
Jeff
The problem is likely the square brackets: try replacing them with regular parentheses. Square brackets are used in COMSOL to indicate units. That's just my .02[USD]. Best, Jeff
Jeff Hiller COMSOL Employee

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Posted: 8 years ago Jun 15, 2016, 1:16 p.m. EDT
...and exponential of x is exp(x).
Jeff
...and exponential of x is exp(x). Jeff
Nicholas Goldring Certified Consultant
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Posted: 8 years ago Jun 15, 2016, 1:31 p.m. EDT
Awesome, thanks Jeff!
Awesome, thanks Jeff!

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