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magnetic BH Curve
Posted Aug 22, 2015, 4:56 a.m. EDT 1 Reply
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Hi, I need to add a B H curve I've measured, and I see when I add a non-linear material I can see it's interpolation points, but there are no units? I don't know how to import from a file so I thought it would be quicker to just re-type my data for my curve over an existing one.
See attached picture for is what it looks like. I assume the verticle f(t) is magnetic flux density in Tesla, but what is 't'? Is it H [A/m]? Or time?
Thanks a lot!
See attached picture for is what it looks like. I assume the verticle f(t) is magnetic flux density in Tesla, but what is 't'? Is it H [A/m]? Or time?
Thanks a lot!
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1 Reply Last Post Aug 23, 2015, 3:28 p.m. EDT
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Posted:
9 years ago
Hi
Indeed COMSOL has units (almost) everywhere so one can get somewhat confused with the functions.
Mostly these are defined in a generic way so here "t" is a dummy variable used to define f(t) but it could just as well be f(x) with x another "dummy" variable.
Most functions are dimensionless so its up to you to define the calling sequence to get the units correctly mapped, you may use calls like "f(my_H[1/(A/m)])*1[T]" to ensure the variable my_H is mapped to A/m then made unitless and that the results is defined in T for Tesla.
In the "analytical function" you have the option to change the argument name and its units, as well as the units of the expression, but not for tabular interpolations functions.
Check out some examples in the Model library or in the application docs
--
Good luck
Ivar
Indeed COMSOL has units (almost) everywhere so one can get somewhat confused with the functions.
Mostly these are defined in a generic way so here "t" is a dummy variable used to define f(t) but it could just as well be f(x) with x another "dummy" variable.
Most functions are dimensionless so its up to you to define the calling sequence to get the units correctly mapped, you may use calls like "f(my_H[1/(A/m)])*1[T]" to ensure the variable my_H is mapped to A/m then made unitless and that the results is defined in T for Tesla.
In the "analytical function" you have the option to change the argument name and its units, as well as the units of the expression, but not for tabular interpolations functions.
Check out some examples in the Model library or in the application docs
--
Good luck
Ivar