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BH-Curve in comsol 4.0
Posted 17.01.2011, 06:08 GMT-5 2 Replies
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Hello,
im trying to set up an quasistationary analysis of a coil with an iron core and would like to use the BH-curve of the build in material "soft iron without losses". For the part that will be of soft iron i use a seperate "amperes law" feature as for the rest of the model. Under "magnetic field" i use HB curve as the constitutive relation and for |H| i chose "from material". But the results look like the µr is constant?! Where's the mistake?
Any help would be greatly appreciated.
im trying to set up an quasistationary analysis of a coil with an iron core and would like to use the BH-curve of the build in material "soft iron without losses". For the part that will be of soft iron i use a seperate "amperes law" feature as for the rest of the model. Under "magnetic field" i use HB curve as the constitutive relation and for |H| i chose "from material". But the results look like the µr is constant?! Where's the mistake?
Any help would be greatly appreciated.
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2 Replies Last Post 21.01.2011, 02:14 GMT-5
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Posted:
1 decade ago
I have attached the model file, maybe this could be useful
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Posted:
1 decade ago
Hi
a few comments first:
I see you have nicely rounded off most corners (there is 1 missing) that is good it improves the precision as a straight corner in ACDC represents a singularity, But then why not push it to so you use a half a circle for the "air/vacuum" volume, as then the field lines loops around more regularly, and you can use simpler spherical infinite elements
Then you have chosen "MEF", do you really need to solve for "V" ? anyhow then you should also give some low conductivity to the air, otherwise your solver will have problems something like 1 to 1000 S/m will do, anyhow negligible w.r.t copper. And be sure you have a GND or corresponding somewhere for the V BC
Then for variable names, I always use "long names" as most single letters are already used by COMSOL and reusing an internal variable (without knowing it) gives often errors that are difficult to track. In your case with "f" I believe its OK anyhow.
You have a very dense mesh there, that's OK for a final run, but to debug, you can often use the default values of COMSOL
I still need some time to analyse the model better
--
Good luck
Ivar
a few comments first:
I see you have nicely rounded off most corners (there is 1 missing) that is good it improves the precision as a straight corner in ACDC represents a singularity, But then why not push it to so you use a half a circle for the "air/vacuum" volume, as then the field lines loops around more regularly, and you can use simpler spherical infinite elements
Then you have chosen "MEF", do you really need to solve for "V" ? anyhow then you should also give some low conductivity to the air, otherwise your solver will have problems something like 1 to 1000 S/m will do, anyhow negligible w.r.t copper. And be sure you have a GND or corresponding somewhere for the V BC
Then for variable names, I always use "long names" as most single letters are already used by COMSOL and reusing an internal variable (without knowing it) gives often errors that are difficult to track. In your case with "f" I believe its OK anyhow.
You have a very dense mesh there, that's OK for a final run, but to debug, you can often use the default values of COMSOL
I still need some time to analyse the model better
--
Good luck
Ivar