Model Gallery

The Model Gallery features COMSOL Multiphysics model files from a wide variety of application areas including the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use models and step-by-step instructions for building the model, and use these as a starting point for your own modeling work. Use the Quick Search to find models relevant to your area of expertise, and login or create a COMSOL Access account that is associated with a valid COMSOL license to download the model files.

Static Field Modeling of a Halbach Rotor

This model presents the static field modeling of an outward flux focusing magnetic rotor using permanent magnets. This magnetic rotor is also often called a Halbach rotor. The use of permanent magnets in rotatory devices such as motors, generators and magnetic gears is increasing. The accurate modeling of a permanent magnets fields is important. This model illustrates how to calculate the ...

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.

Electron Beam Diverging Due to Self Potential

When modeling the propagation of charged particle beams at high currents, the space charge force generated by the beam significantly affects the trajectories of the charged particles. Perturbations to these trajectories, in turn, affect the space charge distribution. The Charged Particle Tracing interface can use an iterative procedure to efficiently compute the strongly coupled particle ...

Small-Signal Analysis of an Inductor

If an inductor's magnetic material is nonlinear, then the inductance depends on the current passing through it. This model consists of an inductor with a nonlinear magnetic core, where the small-signal inductance is simulated as a function of current. The model also investigates how the small-signal inductance depends on the DC current.

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.

Geoelectrics - Forward Problem and Sensitivity

The classical forward problem of geoelectrics (includes electrical resistivity tomography, ERT and earlier techniques as vertical electric sounding, VES) is the calculation of potentials at a given set of electrodes (M,N) while current is injected at other electrodes (A,B) into the ground. Typically the physical domain (earth) is unbounded to the sides and the bottom because of which one needs ...

Multipactor

Multipaction can occur when electrons are accelerated by a high frequency RF field into surfaces. Secondary electron emission can occur and under the right conditions there can be an exponential growth in the number of electrons. The multipaction effect is strongest at a specific RF frequency, which depends on the dimensions of the device and the applied voltage.\n\nThis model requires the ...

Capacitance in a Microstrip

To illustrate how to calculate lumped parameters of capacitance, this model calculates such in a microstrip. The example shows the two different ways of calculating this: with a static analysis and with a time-harmonic analysis.

Cold Crucible

A cold crucible is used for the manufacturing of alloys that require a high degree of purity, like titanium alloys for the aeronautic industry. The cold crucible in this model is made of several water-cooled copper sectors that form the container in which the alloy is manufactured. The harmonic current flowing in the coils will induce a current in the crucible flowing in the opposite ...

Focusing Ions with a Quadrupole Lens

Just like optical lenses focus light, electric and magnetic lenses can focus beams of charged particles. Systems of magnetic quadrupole lenses find a common use in focusing both ion and particle beams in accelerators at nuclear and particle physics centers. This model shows the path of ions going through three consecutive magnetic quadrupole lenses. The model also takes fringing fields ...

Quick Search