The Application Gallery features COMSOL Multiphysics^{®} tutorial and demo app files pertinent to the electrical, structural, acoustics, fluid, heat, and chemical disciplines. You can use these examples as a starting point for your own simulation work by downloading the tutorial model or demo app file and its accompanying instructions.

Search for tutorials and apps relevant to your area of expertise via the Quick Search feature. To download the MPH-files, log in or create a COMSOL Access account that is associated with a valid COMSOL license. Note that many of the examples featured here can also be accessed via the Application Libraries that are built into the COMSOL Multiphysics^{®} software and available from the *File* menu.

### Electromagnetic Plunger with Stopper

This is a transient model of an electromagnetic plunger with stopper restricting the linear motion. The model consists of a magnetic core, nonmagnetic guider, multi-turn coil, nonmagnetic stopper/blocker, and magnetic plunger attached to the spring and damper at the far end. The electromagnetic force on the plunger due to the transient current in the coil is calculated using the Maxwell stress ...

### Electromagnetic Force Verification Series

In this set of verification models and associated documentation, the accuracy of electromagnetic force calculations is investigated. Using various techniques, the total force and torque on a rigid body is determined and compared to analytical models. Using fillets, advanced meshing and exterior force-probe surfaces the accuracy is greatly increased. The boundary element method (BEM) and the ...

### 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 ...

### Electromagnetic Force Calculation Using Virtual Work and Maxwell Stress Tensor

The model compare the electromagnetic force calculated by *virtual work* and *maxwell stress tensor* methods on the axial magntic bearing. The forces is evaluated by studying the effect of a small displacement on the electromagnetic energy of the system. This is done by using the *Magnetic Fields*, *Deformed Geometry* and *Sensitivity* physics interfaces.

### Comparison of Effective H-B/B-H Curve with Linear and Nonlinear Material Models

This example illustrates how to set up the effective H-B/B-H curve material model, introduced in COMSOL Multiphysics® version 5.2, for modeling magnetic materials in the frequency domain. The model also compares the results from the effective H-B/B-H curve model with the linear and nonlinear H-B/B-H curve material model in 2D.

### 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 ...

### Busbar, AC Analysis

This is a busbar configuration with an AC analysis. The configuration is similar to the introductory tutorial in the book Introduction to COMSOL Multiphysics. However, two conductors are added to represent a more realistic case of magnetic fields surrounding the busbar. The results include Lorentz forces, induced currents, magnetic flux, and temperature.

### Modeling a Capacitive Position Sensor Using FEM

This tutorial model explains how to extract lumped matrices by means of the *Stationary Source Sweep* study. The capacitance matrix of a five-terminal system is used to infer the position of a metallic object similar to real-world capacitive position sensors. The example illustrates the use of FEM, which is supported by the *Electrostatics* interface. When FEM is used, a volumetric mesh of a ...

### Iron Sphere in a 13.56 MHz Magnetic Field

An iron sphere is exposed to a spatially uniform, sinusoidally time-varying, background magnetic field. The frequency of the field is so high that the skin depth in the sphere is much smaller than the radius. At such high frequencies it is possible to model only the fields and induced currents on the surface of the sphere, thus avoiding the need for solving for the fields within the volume of ...

### Computing Intercepted Flux

This example model demonstrates four different approaches for computing the integrals of fields over arbitrarily placed geometries that can be re-positioned without having to re-solve the model. This approach is also useful if you want to integrate the results of a model over different sub-regions that you do not want to include in your original computational model. The example of computing ...