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.

Electric Impedance Sensor

Electric impedance measurements are used for imaging and detection. Applications range from nondestructive testing and geophysical imaging to medical imaging. Several alternative techniques are shown to model such a system. One of them shows how to use conditional expressions to define spatially dependent material properties. Another shows how to use multiple terminals for distributed sensing ...

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.

Axisymmetric approximation of 3D Inductor

Inductive devices experience capacitative coupling between conductors at high frequencies. Modeling this phenomenon requires that you describe electric fields that have components both parallel with and perpendicular to the wire. This consideration might lead to the conclusion that a 3D model is always necessary to model the phenomenon, even if the coil is a helix, which is actually not the ...

Comparison of Effective HB/BH Curve with Linear and Nonlinear Material Models

This example illustrates how to setup the Effective HB/BH Curve material model, introduced in COMSOL 5.2, for modeling the magnetic materials in frequency domain. The model also compares the results from Effective HB/BH Curve model with the linear and nonlinear HB/BH Curve material model in 2D.

Touchscreen Simulator

Intended as a tool for early proof of concept in capacitive touchscreen device development, the Touchscreen Simulator app evaluates a simulated capacitance matrix as well as the electric field norm. The app computes the capacitance matrix of a touchscreen in the presence of a human finger phantom, where the position and orientation of the finger are controlled via input parameters. This ...

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 ...

Axial Field Magnetic Gear in 3D

In this model, an axial field magnetic gear with a gear ratio of 5:2 is modeled. Both the high speed and low speed rotors consist of permanent magnet and back iron. The low speed rotor consists of five pole-pairs, while the high speed rotor consists of two pole pairs, and the stationary steel consists of seven pole-pairs. The *Rotating Machinery, Magnetic* interface is used to evaluate the ...

Simulation of RF Tissue Ablation

This example exemplifies how to model tissue ablation through applying RF radiation. A more detailed description of the phenomenon, and the modeling process, can be seen in the blog post "[Study Radiofrequency Tissue Ablation Using Simulation](https://www.comsol.com/blogs/study-radiofrequency-tissue-ablation-using-simulation/)".

Iron Sphere in a 60 Hz Magnetic Field

An iron sphere is exposed to a spatially uniform, sinusoidally time-varying, background magnetic field. The frequency of the field is low enough such that the skin depth is larger than the radius of the sphere. A reduced field formulation is used to impose the background field. Two approaches for solving this problem are shown. The induced currents in the sphere and the perturbation to the ...

External Material, AC/DC Module, General HB/BH relation

The AC/DC magnetic interfaces now support material models defined in external C code. A new way to specify user-defined material models is included in COMSOL Multiphysics version 5.2. You can now access external material functions, written in C code, which have been compiled into a shared library. By writing a wrapper function in C code, you can also use material functions written in another ...