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[solved] Call functions in 4.3a
Posted Nov 17, 2012, 8:42 a.m. EST 2 Replies
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Hi
I created an interpolation fonction in the global definitions node. I need to use that function as an excitation in a bondary condition and simulate according to that interpolation. So, I put "Int1" (without brackets) in the according space in the BC node. But, it appears with the orange color and I've got an error message telling me that Comsol doesn't understand the included function. I searched in the forum to no avail and the docs related to that point are quite vague concerning the calling of the functions.
How should I do to correctly call this type of functions in the simulation ?
Thanks a lot
I created an interpolation fonction in the global definitions node. I need to use that function as an excitation in a bondary condition and simulate according to that interpolation. So, I put "Int1" (without brackets) in the according space in the BC node. But, it appears with the orange color and I've got an error message telling me that Comsol doesn't understand the included function. I searched in the forum to no avail and the docs related to that point are quite vague concerning the calling of the functions.
How should I do to correctly call this type of functions in the simulation ?
Thanks a lot
2 Replies Last Post Nov 19, 2012, 5:32 a.m. EST
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Posted:
1 decade ago
Hi
first of all orange means normally unit incoherence, it's a Warning, not formally an Error, as COMSOL will calculate een if you have unit errors.
so first thing functions, if you have not defined explicitely in their definition that thy have units, do not transport with them the unts COMSOL expect to find, so often one need to add thse by a 1[W/m^2]*int1(...).
The second point is that normally a function has arguments and expression (or interpolation values), so you need to define the arguments in your funcion call, you need to set something in the brakets.
There are some cases when you can define imported multi argument functions as depending on the spatial variables, but then you should also take care to adapt accordingly offset and signs (directions). As your geoemtry might move around in space
--
Good luck
Ivar
first of all orange means normally unit incoherence, it's a Warning, not formally an Error, as COMSOL will calculate een if you have unit errors.
so first thing functions, if you have not defined explicitely in their definition that thy have units, do not transport with them the unts COMSOL expect to find, so often one need to add thse by a 1[W/m^2]*int1(...).
The second point is that normally a function has arguments and expression (or interpolation values), so you need to define the arguments in your funcion call, you need to set something in the brakets.
There are some cases when you can define imported multi argument functions as depending on the spatial variables, but then you should also take care to adapt accordingly offset and signs (directions). As your geoemtry might move around in space
--
Good luck
Ivar
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Posted:
1 decade ago
Thanks for the reply.
According to what you have said, this is what I did :
In the global definitions, I declared "t" as a variable and I've put "t" as its expression. COMSOL seems to have understood that since it automatically put "s" as a unit.
In the boundary condition excitation space, I've put : "1[A/m^2]*int1(t[1/s])". This seems to be right since it's no more orange but finally black.
But when I run the simulation the result is wrong since I've got no excitation and all the values are null.
What have I missed, please ?
EDIT : Problem solved. Thanks for your help
According to what you have said, this is what I did :
In the global definitions, I declared "t" as a variable and I've put "t" as its expression. COMSOL seems to have understood that since it automatically put "s" as a unit.
In the boundary condition excitation space, I've put : "1[A/m^2]*int1(t[1/s])". This seems to be right since it's no more orange but finally black.
But when I run the simulation the result is wrong since I've got no excitation and all the values are null.
What have I missed, please ?
EDIT : Problem solved. Thanks for your help