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Global constraint

Posted 18 mars 2013, 15:12 UTC−4 Version 4.3a 2 Replies

Morten Hygum
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Hi,

I am modelling thermodiffusion of moisture with the mathematical module. Is it possible impose a constraint to the concentration, c, in order to ensure it stays positive.
2 Replies Last Post 19 mars 2013, 02:49 UTC−4
Nagi Elabbasi Facebook Reality Labs
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Posted: 1 decade ago 18 mars 2013, 16:37 UTC−4
A negative concentration is frequently a sign of an incorrectly defined physics, coarse mesh or large time steps in a transient analysis. In general you don’t need a constraint to enforce the concentration to stay non-negative.

Nagi Elabbasi
Veryst Engineering
A negative concentration is frequently a sign of an incorrectly defined physics, coarse mesh or large time steps in a transient analysis. In general you don’t need a constraint to enforce the concentration to stay non-negative. Nagi Elabbasi Veryst Engineering
Morten Hygum
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Posted: 1 decade ago 19 mars 2013, 02:49 UTC−4
Thank you for your response.

I am not using using the bulit-in modules. I needed to use the math module.
Thank you for your response. I am not using using the bulit-in modules. I needed to use the math module.

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