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problem with time dependent phase transition model

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Hi all,
I've built a model which involves a phase transition.
I want to see how long does it take for the phase transition to occur.
when I run the model with range(0,2,800) it gives logical results
with the typical graph of temperature vs. time where the temperature stays the same
as long as the phase transition occurs. But, when I run with (0,2,900), the phase
transition disappears and I get a graph with a continues temperature rise.
Is there anyone who encountered the same problem or has a solution?

thank you,
Zvika

2 Replies Last Post Sep 10, 2013, 1:19 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Oct 24, 2011, 1:21 a.m. EDT
Hi

I can make a guess, it might be something else, but when you give a series to the solver, and leave the solver settings to default "Automatic" the solver will not solve strictly at each point you give, but might skip several, depending on the Jacobian of your system (derivative of the variables), so if you reach a regular intercase, the solver might skip over the non-linear transition. Try to use an "intermediate" or "strict" stepping method. See the solver node settings

--
Good luck
Ivar
Hi I can make a guess, it might be something else, but when you give a series to the solver, and leave the solver settings to default "Automatic" the solver will not solve strictly at each point you give, but might skip several, depending on the Jacobian of your system (derivative of the variables), so if you reach a regular intercase, the solver might skip over the non-linear transition. Try to use an "intermediate" or "strict" stepping method. See the solver node settings -- Good luck Ivar

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Posted: 1 decade ago Sep 10, 2013, 1:19 p.m. EDT
hi


can the phase transition be stimulated in microchannel?
which module will give the best result??

thanks
ajith
hi can the phase transition be stimulated in microchannel? which module will give the best result?? thanks ajith

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