diff --git a/Magnetostatics/electromagnet.pro b/Magnetostatics/electromagnet.pro index 05bed253e8f2b70e2138927403410f5e5d175f2f..57774df8709bee5359730b2a1ccbcdfab1645883 100644 --- a/Magnetostatics/electromagnet.pro +++ b/Magnetostatics/electromagnet.pro @@ -15,7 +15,20 @@ Run (button at the bottom of the left panel) ------------------------------------------------------------------- */ -/* Electromagnetic fields expand to infinity. The corresponding boundary +/* This model computes the static magnetic field produced by a DC current. This + corresponds to a "magnetostatic" physical model, obtained by combining the + time-invariant Maxwell-Ampere equation (curl h = js, with h the magnetic + field and js the source current density) with Gauss' law (Div b = 0, with b + the magnetic flux density) and the magnetic constitutive law (b = mu h, with + mu the magnetic permeability). + + Since Div b = 0, b can be derived from a vector magnetic potential a, such + that b = curl a. Plugging this potential in Maxwell-Ampere's law and using + the constitutive law leads to a vector Poisson equation in terms of the + magnetic vector potential: curl(nu curl a) = js, where nu = 1/mu is + the reluctivity. + + Electromagnetic fields expand to infinity. The corresponding boundary condition can be imposed rigorously by means of a gometrical transformation that maps a ring (or shell) of finite elements to the complementary of its interior. As this is a mere geometric transformation, it is enough in the @@ -38,20 +51,7 @@ editable in the GUI before running the model. Such variables are called ONELAB variables (because the sharing mechanism between the model and the GUI uses the ONELAB interface). ONELAB parameters are defined with a - "DefineNumber" statement, which can be invoked in the .geo and .pro files. - - This model computes the static magnetic field produced by a DC current. This - corresponds to a "magnetostatic" physical model, obtained by combining the - time-invariant Maxwell-Ampere equation (curl h = js, with h the magnetic - field and js the source current density) with Gauss' law (Div b = 0, with b - the magnetic flux density) and the magnetic constitutive law (b = mu h, with - mu the magnetic permeability). - - Since Div b = 0, b can be derived from a vector magnetic potential a, such - that b = curl a. Plugging this potential in Maxwell-Ampere's law and using - the constitutive law leads to a vector Poisson equation in terms of the - magnetic vector potential: curl(nu curl a) = js, where nu = 1/mu is - the reluctivity. */ + "DefineNumber" statement, which can be invoked in the .geo and .pro files. */ Group { // Physical regions: