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Pointwise constraint

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Hi all,

I have a model in which absorption of a certain mass takes place according to a chemical reaction which is pressure dependent. At a certain point when the pressure becomes equal to or less than the equilibrium pressure, the reaction should cease however, it is going on but when I put a pointwise constraint on mass absorbed, the reaction stops. I would just like to know why is this happening and how does a pointwise constraint work in comsol?

Mass absorbed= C*exp(-E/(R*T))*log(p/P1)*(rhop-rhom)
(so if P1=p the reaction should stop on the condition: P1=Peq+(p-Peq)*(Peq>=p))

But my reaction is going on and is stopping only when I apply a pointwise constraint. I just want to know why this is happening.

Thanks,
Mahvash

0 Replies Last Post 1 avr. 2016, 02:24 UTC−4
COMSOL Moderator

Hello Mahvash Afzal

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