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how to set output of an stationary model as initial value for a time dependent model?

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hi every body,

I have a model consisting of two equations(one stationary and one time dependent). answer of first equation is initial condition for the second. solution of each equation is OK. but i do not know how to couple two equations?

Normally I add an stationary study, then I add a time dependent study to this study, then i use "show default solver" and after that i try to run the study but it does not work.

can anyone help me?

10 Replies Last Post 28 mars 2015, 18:01 UTC−4

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Posted: 1 decade ago 6 juil. 2011, 18:40 UTC−4
Please send ur model so we Can help u ...
Please send ur model so we Can help u ...

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Posted: 1 decade ago 8 juil. 2011, 10:07 UTC−4
Hi sam,

please find the attachment. stationary and time dependent studies are working properly.
but coupling two solution is not successful.

kind regards,
Mohammad
Hi sam, please find the attachment. stationary and time dependent studies are working properly. but coupling two solution is not successful. kind regards, Mohammad


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Posted: 1 decade ago 20 juil. 2011, 15:01 UTC−4
In fact U have to treat ur own Equations ... I don't know what is the physics but i am sure u can change to have only one Equation and one study as stationary study is a specific case of time dependent (in my opinion).
In fact U have to treat ur own Equations ... I don't know what is the physics but i am sure u can change to have only one Equation and one study as stationary study is a specific case of time dependent (in my opinion).

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Posted: 1 decade ago 20 juil. 2011, 17:02 UTC−4
Solve transient problem, store solution. Then in solver manager, solve stationary problem with initial value setting, initial value evaluated using stored solution
Solve transient problem, store solution. Then in solver manager, solve stationary problem with initial value setting, initial value evaluated using stored solution

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Posted: 1 decade ago 19 sept. 2011, 13:55 UTC−4
Hello Mohamad,

could you please let me know if you had solved the problem? I am working on similar problem. Also are you using COMSOL 3.5a?
Hello Mohamad, could you please let me know if you had solved the problem? I am working on similar problem. Also are you using COMSOL 3.5a?

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Posted: 1 decade ago 25 sept. 2011, 15:36 UTC−4
hi Subhra,

yes i've found the soluiton. I'm working with 4.2
hi Subhra, yes i've found the soluiton. I'm working with 4.2

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Posted: 1 decade ago 4 oct. 2011, 06:12 UTC−4
Hey Mohamad,

and how did you solve the problem? I have a similar problem, so it might help to know what you did.

Regards
Hannah
Hey Mohamad, and how did you solve the problem? I have a similar problem, so it might help to know what you did. Regards Hannah

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Posted: 1 decade ago 4 oct. 2011, 06:34 UTC−4
hi Hannah,

you can set two studies, first stationary and then time dependent. choose solver at the time dependent solver, afterwards select dependent variables, u can set the input parameters from another solver.

goo luck,
Mohammad
hi Hannah, you can set two studies, first stationary and then time dependent. choose solver at the time dependent solver, afterwards select dependent variables, u can set the input parameters from another solver. goo luck, Mohammad

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Posted: 1 decade ago 4 oct. 2011, 07:36 UTC−4
Thanks Mohamad!!
Thanks Mohamad!!

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Posted: 10 years ago 28 mars 2015, 18:01 UTC−4
Hello, Mohammad
Would you please send your successful coupling file to me? I have the same problem. Many thanks.
Lanju
Hello, Mohammad Would you please send your successful coupling file to me? I have the same problem. Many thanks. Lanju

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