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Limit a variable

Posted May 26, 2016, 10:43 a.m. EDT Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.2 0 Replies

Simon Reisz
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Hi,

I have a relatively simple question that I couldn't find an answer for in the forums. I am using the General Form PDE mode to solve for a dependent variable, u. From the physics of the problem, I know that the value is between 0 and 1.
However, due to numerics, I obtain values higher and lower than the limits values.
I tried at least to put a lower limit, near 0 like 10^-6. Even with that i can see, in some cases that the variable u can be negative. Even with good BC set-up, i still got the same problem of unstability, or of
inconsistent value.
I also tried to put an other General Forme PDE to limit the variable, and as well a global constraint, without success.


Thanks for your help !

Regards,

Simon
0 Replies Last Post May 26, 2016, 10:43 a.m. EDT
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