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Using Continuation to optimize a value

Posted 7 nov 2012, 12:57 GMT-5 Fluid & Heat, Computational Fluid Dynamics (CFD), Results & Visualization, Studies & Solvers Version 4.3a 3 Replies

Rui Silva
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Hello folks,

I am wondering if it is possible to use the Continuation feature in the solver to optimize a value.

For instance, have a flow in a pipe and using some data like pressure drop, velocity, etc as a reference, and then optimize 2 or 3 empiral constants so they match the data.

Is this possible?

Hope it is clear.

Best Regards,

Rui
3 Replies Last Post 7 nov 2012, 13:32 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 7 nov 2012, 13:07 GMT-5
Hi

the Solver continuation tab is good to scan some values and to derive some other variables and see how these change (and occasionally identfy a optimum max or min).

Another way is to define a global variable to be minimised such that it represents an error function from some parameter deviation and hence optimise directly onto your desired max-min value. But if you have several variables its better to have the optimiation module, its made specifically for that process

--
Good luck
Ivar
Hi the Solver continuation tab is good to scan some values and to derive some other variables and see how these change (and occasionally identfy a optimum max or min). Another way is to define a global variable to be minimised such that it represents an error function from some parameter deviation and hence optimise directly onto your desired max-min value. But if you have several variables its better to have the optimiation module, its made specifically for that process -- Good luck Ivar
Rui Silva
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Posted: 1 decade ago 7 nov 2012, 13:11 GMT-5
Thank you for your reply Ivar!

But the continuation can use combination of parameters, correct?

Would that work if i defined 5 global variables, for instance?

And how would I define the max and min values? I am bit confused on that part.

Could you provide some more info, please. Or an example in the comsol literature.

Best Regards,

Rui
Thank you for your reply Ivar! But the continuation can use combination of parameters, correct? Would that work if i defined 5 global variables, for instance? And how would I define the max and min values? I am bit confused on that part. Could you provide some more info, please. Or an example in the comsol literature. Best Regards, Rui
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 7 nov 2012, 13:32 GMT-5
Hi
You can add several parameters, but you must decide if these are read as column combination, one colun at the time, or as full combinatory selelction.

Chekc ht emodel library and the Forum, the search of a global value such that the model matches a given desired set point is an optimisation often used and described. For 2 its the same, but you need also to give some initial or derivative points to help theslver to find the corect value

--
Good luck
Ivar
Hi You can add several parameters, but you must decide if these are read as column combination, one colun at the time, or as full combinatory selelction. Chekc ht emodel library and the Forum, the search of a global value such that the model matches a given desired set point is an optimisation often used and described. For 2 its the same, but you need also to give some initial or derivative points to help theslver to find the corect value -- Good luck Ivar

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