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.

Axial Homopolar Induction Bearing in 3D

This model illustrates the working principle of an axial homopolar induction 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 axial ...

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 ...

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.

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.

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.

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.

Magnetic Signature of a Submarine

A vessel traveling on the surface or under water gives rise to detectable local disturbances in the Earth’s magnetic field. These disturbances can be used to trigger weapon systems. The magnetic signature of a ship can be reduced by generating a counteracting magnetic field of suitable strength and direction based on prior knowledge of the magnetic properties of the vessel. This model ...

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.

Tunable MEMS Capacitor

In an electrostatically tunable parallel plate capacitor, the distance between the two plates can be modified by a spring, as the applied voltage changes. For a given voltage difference between the plates, the distance of the two plates can be computed, if the characteristics of the spring are known. Knowledge of this means that the distance between the plates can be tuned via the spring. ...

Homopolar Generator 3D

A homopolar generator is composed of an electrically conductive rotating disc placed in a uniform magnetic field that is perpendicular to the plane of rotation. The motion of the conductor through the static magnetic field induces Lorentz currents in the disc. By connecting the outside rim of the disc to the center via a stationary conductor, significant current can be generated. The flow of ...