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Passing post processing result to another study

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Hi,

I was wondering if its possible to do some calculations to results from a study then pass those to another study and run that? More specifically, I want to calculate the inductance of a finite element model that acts like an inductor, then pass that inductance value to an circuit model containing just a normal inductor, and measure the current through that circuit. I can't integrate the model with the circuit physics because of the AC/DC physics I'm using doesn't lend itself nicely to that formulation.

Instead, I'd like to calculate the inductance by integrating the magnetic energy density in the inductor and the total current going through the inductor, finding the inductance that way (think W=1/2LI^2). Then send those calculated values for the inductance (and also voltage) of the finite element model to a normal circuit study. Conceivably I could do this in two separate COMSOL applications, but I'd like to do it in the same application.

Best, Henry


2 Replies Last Post 2018/07/19 21:34 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 6 years ago 2018/07/19 11:41 GMT-4

Hi

I believe its possible, but you must distinguish correctly what kind of variable: * global scalar, or global time dependent, or * a field depending on (x,y,z) or even (x,y,z,t).

For the first one if you define it under the Global or Component Local "Definition" node based on a study case it can be called up from a different Component by using the full name "root.var1.MyVar" or "comp1.var2.MyVar" provided the first solution exist and is solved.

If it's a field depending on (x,y,z) you have the issue that you must also map the comp1.(x,y,z) to the appropriate comp2.(x.y.z) to get a match for the spatial variables, this might be done with the component "Couplings and Coupling Operators" (note also the issue with the potential use of the nojac() operator).

And for a time series you must ensure that your "t" time variable is defined correctly between the two studies, or use some of the operators such as the "at()" , "with()" , "witsol()" .

Some of these operators might only be used for postprocessing. Check the doc, there are many ways but also some issues here.

Be careful though, if you have only ONE component "comp1." and different studies therein "std1 , std2 ..." , your local defined variables "comp1.var2.MyVar" will be recalculated "per study" and you are not linking the studies.

God luck Ivar

-------------------
Have fun COMSOLing,
Sincerely,
Ivar
Hi I believe its possible, but you must distinguish correctly what kind of variable: * global scalar, or global time dependent, or * a field depending on (x,y,z) or even (x,y,z,t). For the first one if you define it under the Global or Component Local "Definition" node based on a study case it can be called up from a different Component by using the full name "root.var1.MyVar" or "comp1.var2.MyVar" provided the first solution exist and is solved. If it's a field depending on (x,y,z) you have the issue that you must also map the comp1.(x,y,z) to the appropriate comp2.(x.y.z) to get a match for the spatial variables, this might be done with the component "Couplings and Coupling Operators" (note also the issue with the potential use of the nojac() operator). And for a time series you must ensure that your "t" time variable is defined correctly between the two studies, or use some of the operators such as the "at()" , "with()" , "witsol()" . Some of these operators might only be used for postprocessing. Check the doc, there are many ways but also some issues here. Be careful though, if you have only ONE component "comp1." and different studies therein "std1 , std2 ..." , your local defined variables "comp1.var2.MyVar" will be recalculated "per study" and you are not linking the studies. God luck Ivar

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Posted: 6 years ago 2018/07/19 21:34 GMT-4

Hi Ivar,

Thank you, this helped a lot.

Best, Henry

Hi Ivar, Thank you, this helped a lot. Best, Henry

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