Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

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

Please login with a confirmed email address before reporting spam

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 Mar 28, 2015, 6:01 p.m. EDT

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jul 6, 2011, 6:40 p.m. EDT
Please send ur model so we Can help u ...
Please send ur model so we Can help u ...

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jul 8, 2011, 10:07 a.m. EDT
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


Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jul 20, 2011, 3:01 p.m. EDT
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).

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jul 20, 2011, 5:02 p.m. EDT
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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 19, 2011, 1:55 p.m. EDT
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?

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 25, 2011, 3:36 p.m. EDT
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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Oct 4, 2011, 6:12 a.m. EDT
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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Oct 4, 2011, 6:34 a.m. EDT
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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Oct 4, 2011, 7:36 a.m. EDT
Thanks Mohamad!!
Thanks Mohamad!!

Please login with a confirmed email address before reporting spam

Posted: 9 years ago Mar 28, 2015, 6:01 p.m. EDT
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

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.