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Solving coupled PDES in comsol
Posted 14.06.2016, 12:22 GMT-4 Version 5.1, Version 5.2 2 Replies
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I have a system where I am solving two different PDEs in COMSOL. The solution to the first PDE is called u and the second is u2. To solve the second one I need to use the solution that COMSOL found for the first PDE, i.e. u enters in the second PDE. How do I do solve this problem such that COMSOL knows to call the solution found from solving the first PDE? I tried to blindly just plug in u in the second PDE but that gives me an error.
The way the problem is set up currently I have two PDEs and two separate studies, one for each PDE.
The way the problem is set up currently I have two PDEs and two separate studies, one for each PDE.
2 Replies Last Post 14.06.2016, 14:03 GMT-4
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Posted:
8 years ago
Hello August,
In principle, what you are doing will work if you implement it correctly (assuming that your equations are only one-way coupled; if they are two-way coupled you need to use a single study). Consider posting a more detailed description of what you want your model to do (equations, BCs, geometry, etc) as well as your mph file if you'd like Discussion Forum users to look at how you tried to set it up.
Best,
Jeff
In principle, what you are doing will work if you implement it correctly (assuming that your equations are only one-way coupled; if they are two-way coupled you need to use a single study). Consider posting a more detailed description of what you want your model to do (equations, BCs, geometry, etc) as well as your mph file if you'd like Discussion Forum users to look at how you tried to set it up.
Best,
Jeff
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Posted:
8 years ago
okay thanks for the answer. The equations are two way coupled and what I do is perform a parametric sweep over the first equation, where I sweep over K*u2, where K=0 at first and then I sweep up to K=1. Here u2 is the solution to the second equation, in which the solution u also enters. So to summarize.
I solve the first PDE for K=0, plug this solution into the second PDE. I then solve this for u2 and put in K*u2, where K is now non-zero (defined by the sweep).
Then I reiterate this process.
I have attached my .mph file. It is written in COMSOL 5.1. I hope that will work for you.
I solve the first PDE for K=0, plug this solution into the second PDE. I then solve this for u2 and put in K*u2, where K is now non-zero (defined by the sweep).
Then I reiterate this process.
I have attached my .mph file. It is written in COMSOL 5.1. I hope that will work for you.
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