La Bibliothèque de Modèles présente des modèles construits avec COMSOL Multiphysics pour la simulation d'une très grande variété d'applications, dans les domaines électrique, mécanique, fluidique et chimique. Vous pouvez télécharger ces modèles résolus avec leur documentation détaillée, notamment les instructions de construction pas à pas, et vous en servir comme point de départ de votre travail de simulation. Utilisez l'outil de recherche rapide pour trouver les modèles correspondant à votre domaine d'intérêt, et connectez vous avec votre compte COMSOL Access, associé à une licence COMSOL, afin de télécharger les fichiers modèles.

Iron Sphere in a 20 kHz Magnetic Field

An iron sphere is exposed to a spatially uniform, sinusoidally time-varying, background magnetic field. The frequency of the field is such that there skin depth is smaller than the sphere radius. The induced currents in the sphere and the perturbation to the background field are computed. Proper meshing of domains with significant skin effect is addressed.

Effective Nonlinear Magnetic Curves Calculator

The Effective Nonlinear Magnetic Curves Calculator application is a companion to the *Effective Nonlinear Constitutive Relations* functionality. Magnetic-based interfaces in the AC/DC Module support the Effective HB/BH Curve material model that can be used to approximate the behavior of a nonlinear magnetic material in a frequency domain simulation without the additional computational cost of a ...

An RFID System

RFIDs are used in a multitude of applications such as tracking or identifying consumer products and their packaging. An RFID system consists of two main parts: A tag or transponder with a printed circuit-board (PCB) antenna A reader unit with a larger RF antennaThe reader antenna generates an electromagnetic field that energizes a chip (IC-circuit) inside the tag. The electromagnetic field ...

Magnetotellurics

Magnetotellurics is a method for estimating the resistivity profile of the Earth's subsurface using the natural electromagnetic source provided by the ionosphere. This model was defined by Zhdanov et al. in a study published in 1997. In this article, various scientific groups compared software performance on the same models. This is the model called COMMEMI-3D-2, which has become one of the ...

Linear Magnetic Gear

In this model, a linear magnetic gear system with a gear ratio of 11:4 is modeled. The liner magnetic gear is assumed to be infinitely long with the modular structure that is repeating on either side. Only a single modular section is modeled by using the customized linear periodic boundary condition. Both the low speed and the high speed armatures (rotors) consist of permanent magnets and back ...

Electrodynamic Bearing

This model illustrates the working principle of a passive electrodynamic bearing. An electrically conducting rotor rotating in a magnetic field produced by a permanent magnets induces eddy currents on the conducting rotor. The eddy currents, in turn, produce a magnetic field that opposes the magnetic fields by the magnets and induces a force that opposes the motion of the rotor. The radial ...

Magnetic Stiffness of an Axial Magnetic Bearing in 3D

The model illustrate the technique to calculate the magnetic stiffness in a 3D geometry of a permanent magnet axial magnetic bearing. The *Magnetic Fields* physics is used to model the bearing and compute the magnetic forces. The *Deformed Geometry* and *Sensitivity* physics are used to compute the magnetic stiffness. This model is featured and explained in much greater detail in the following ...

Magnetically Permeable Sphere in a Static Magnetic Field

A sphere of relative permeability greater than unity is exposed to a spatially uniform static background magnetic field. Two formulations are used to solve this problem, and the differences between these are discussed. The field strength inside the sphere is computed and compared against the analytic solution.

Electric Shielding Comparison

The electric shielding boundary condition is meant to approximate a thin layer of highly conductive material that provides an additional current path tangential to a boundary. This example compares the electric shielding boundary condition to a full-fidelity model and discusses the range of applicability of this boundary condition.

Contact Impedance Comparison

The contact impedance boundary condition is meant to approximate a thin layer of material that impedes the flow of current normal to the boundary, but does not introduce any additional conduction path tangential to the boundary. This example compares the contact impedance boundary condition to a full-fidelity model and discusses the range of applicability of this boundary condition.