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How to set user defined boundary condition

Posted Jan 16, 2012, 10:33 a.m. EST Chemical Reaction Engineering, Materials Version 4.2 3 Replies

ZL Huang
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I'm now trying to calculate heterojunction. As an example of model library， I use the "Transport of Diluted species" model to calculate. But I want to set a condition that " log(n1)+c1=log(n2)+c2" at the boundary. n1, n2 represent the concentration, c1,c2 are different const depending on material. There are no boundary condition same as this need，so how can I set that boundary condition？
3 Replies Last Post Jan 23, 2012, 8:41 a.m. EST
ZL Huang
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Posted: 1 decade ago Jan 17, 2012, 10:02 p.m. EST
I've got some idea about this question. I may use weak constrain, and use 'up' and 'down' function, but I still cannot realize it. How can I set the boundary condition: n1/n2=c, where 'c' is a const and 'n1', 'n2' are the concentration in the two side of the boundary respectively. (i.e. the concentration of the boundary is uncontinuous)

Who have any idea?
THANKS!
I've got some idea about this question. I may use weak constrain, and use 'up' and 'down' function, but I still cannot realize it. How can I set the boundary condition: n1/n2=c, where 'c' is a const and 'n1', 'n2' are the concentration in the two side of the boundary respectively. (i.e. the concentration of the boundary is uncontinuous) Who have any idea? THANKS!
Lechoslaw Krolikowski
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Posted: 1 decade ago Jan 18, 2012, 6:15 a.m. EST
Hi,
I think you can use the so called stiff-spring method.
You'll find it in the Separation Through Dialysis example (Model Library - see pdf file).
Regards,
Andrzej
Hi, I think you can use the so called stiff-spring method. You'll find it in the Separation Through Dialysis example (Model Library - see pdf file). Regards, Andrzej
ZL Huang
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Posted: 1 decade ago Jan 23, 2012, 8:41 a.m. EST
Thank you so much. That document helps me a lot.
Thank you so much. That document helps me a lot.

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