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how to run a time dependent state from the solution of a stationary state?
Posted 20.07.2012, 04:40 GMT-4 Heat Transfer & Phase Change, Studies & Solvers Version 5.1 2 Replies
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hi peeps
so instead of putting 'stationary' and 'time dependent' in a row, I run a 'stationary' state in the first place, when it finishes, I add a 'time dependent' (taking solution from 'stationary' as initial values) after that.
what is the proper step to do that?
Many thanks in advance!
regards
Liwah
so instead of putting 'stationary' and 'time dependent' in a row, I run a 'stationary' state in the first place, when it finishes, I add a 'time dependent' (taking solution from 'stationary' as initial values) after that.
what is the proper step to do that?
Many thanks in advance!
regards
Liwah
2 Replies Last Post 07.04.2017, 06:37 GMT-4
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Posted:
1 decade ago
Hi
you can 1) define one study, use 2 solvers in the same study a stationary and a time dependent, if you start this from scratch (brand new study node, then hit Show default solvers, you will see that COMSOl stores the results of the first (stationary) solver, then uses that as initial conditions for the time stepping one,
the other way you have 2 discinct studies one stationary you solve first, then manualyy you launch the second study a time dependent one. If this is the case YOU must edit the "dependent variables node of your second Time dependent solver sequence and get this one to refer to study 1 stationary results (to decide if it is ONLY for the dependent variables or also for the others too)
These are the "two ways" I know about
--
Good luck
Ivar
you can 1) define one study, use 2 solvers in the same study a stationary and a time dependent, if you start this from scratch (brand new study node, then hit Show default solvers, you will see that COMSOl stores the results of the first (stationary) solver, then uses that as initial conditions for the time stepping one,
the other way you have 2 discinct studies one stationary you solve first, then manualyy you launch the second study a time dependent one. If this is the case YOU must edit the "dependent variables node of your second Time dependent solver sequence and get this one to refer to study 1 stationary results (to decide if it is ONLY for the dependent variables or also for the others too)
These are the "two ways" I know about
--
Good luck
Ivar
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Posted:
8 years ago
Hello,
Sorry for reviving an old topic.
I have a similar issue in Comsol 5.1.
I use the heat transfer module and have a time dependent study with a heat source varying periodically with time. However, reaching the transient part takes too long to simulate so I want to use the solution of a stationary study (with constant heat source) as initial conditions of my time-dependent study.
I thus created two study steps, which work fine separately.
The problem is that since the heat source depends on time, I needed two physics. One in stationary, and one time dependent. Then, the stationary study use the variable T for temperature, while the time dependent physics uses T2. If I use T in the second study I get an error message so I would like to know how to use the output of the stationary solver of T as initial conditions for T2.
Thank you in advance for the help,
Best regards,
Jeremie
Sorry for reviving an old topic.
I have a similar issue in Comsol 5.1.
I use the heat transfer module and have a time dependent study with a heat source varying periodically with time. However, reaching the transient part takes too long to simulate so I want to use the solution of a stationary study (with constant heat source) as initial conditions of my time-dependent study.
I thus created two study steps, which work fine separately.
The problem is that since the heat source depends on time, I needed two physics. One in stationary, and one time dependent. Then, the stationary study use the variable T for temperature, while the time dependent physics uses T2. If I use T in the second study I get an error message so I would like to know how to use the output of the stationary solver of T as initial conditions for T2.
Thank you in advance for the help,
Best regards,
Jeremie