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what is the best way to enter this expression

Posted 18 ago 2011, 01:35 GMT-4 Fluid & Heat, Materials Version 4.2 3 Replies

Sirisha Govindaraju
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Please see the attached file.

I need to enter this expression for my inlet flow velocity. What is the best way to do this?

I have different values for a and b for each value of n. In other words, I have

n=1 to 10
then I have a1,a2,a3 ........a10, b1,b2,.....b10

I was initially planning on entering the expression using "parameters" as a1*exp(omega*t)+a2*exp(omega*t*2)+........+.......
I think there should be a better way to enter this expression than what I was planning on doing.

Should I be using analytic functions to define this?

Thanks for the help.

Sirisha

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3 Replies Last Post 19 ago 2011, 07:48 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 18 ago 2011, 01:59 GMT-4
Hi

I would propose to do it by defining a function for a(n) and b(n) (piecewise type), and call them in with the parameter "n"

--
Good luck
Ivar
Hi I would propose to do it by defining a function for a(n) and b(n) (piecewise type), and call them in with the parameter "n" -- Good luck Ivar
Sirisha Govindaraju
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Posted: 1 decade ago 18 ago 2011, 18:20 GMT-4
Thanks for the response Ivar.
Can I export the piecewise function to use it in some other file? I don't see an option to do it.

Sirisha
Thanks for the response Ivar. Can I export the piecewise function to use it in some other file? I don't see an option to do it. Sirisha
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 19 ago 2011, 07:48 GMT-4
Hi

strange, interpolated functions can be imported / exported, while for piecewise it seems no to be possible.

For me you should ask "support" and suggest is as an "improvement", if they do not have a "good" argument to say why its not that "easy"

--
Good luck
Ivar
Hi strange, interpolated functions can be imported / exported, while for piecewise it seems no to be possible. For me you should ask "support" and suggest is as an "improvement", if they do not have a "good" argument to say why its not that "easy" -- Good luck Ivar

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