The Application Gallery features COMSOL Multiphysics tutorial and demo app files pertinent to the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use tutorial models and demo apps with step-by-step instructions for how to create them yourself. The examples in the gallery serve as a great starting point for your own simulation work.

Use the Quick Search to find tutorials and apps relevant to your area of expertise. Log in or create a COMSOL Access account that is associated with a valid COMSOL license to download the MPH-files.

Transient Modeling of a Capacitor in a Circuit

A transient model of a capacitor is solved in combination with an external electrical circuit. The finite element model of the capacitor is combined with a circuit model of a voltage source and a resistor. A step change in voltage is applied, and the transient current through the capacitor is computed and compared to the analytic result.

Multi-Turn Coil Winding around a Ferromagnet

A demo model of a 50 Hz AC coil wound around a ferromagnetic (linear) core. The model is intended as a tutorial to show how to create a relatively complex geometry and set up the new Multi-Turn Coil features for the simulation. The model requires the Design module to fillet the edges of the block.

Voltage Induced in a Coil by a Moving Magnet

A magnet moving axially through the center of a coil will induce a voltage across the coil terminals. One practical application of this is in shaker flashlights, where the flashlight is vigorously shaken back and forth, causing a magnet to move through a multi-turn coil, which provides charge to the battery. In this model, the motion of a magnet through a coil is modeled, and the induced ...

Magnetic Brake

A magnetic brake consists of a permanent magnet, which induces currents in a rotating copper disk. The resulting eddy currents interact with the magnetic flux to produce Lorentz forces and subsequently a braking torque. This 3D problem is solved using a stationary formulation for the electromagnetic field coupled to an ordinary differential equation for the rotational rigid body dynamics. ...

Integrated Square-Shaped Spiral Inductor

This model considers a square inductor that is used for LC bandpass filters in MEMS systems. The simulation calculates the self-inductance. The first step in the modeling is to compute the currents in the inductor. These currents are the source for the magnetic flux computations, carried out in a second step.

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 ...

Generator Models in 2D and 3D

These models demonstrate how to setup a sector model of rotating machinery both in 2D and 3D using *Rotating Machinery, Magnetic* interface in COMSOL Multiphysics. The stator in these permanent magnet ac generator examples consists of stator winding backed by iron core. The rotor includes the permanent magnets and iron core. The 2D and 3D model of the generator are included here. In 2D, the ...

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 ...

Eddy Currents in a Cylinder

The eddy currents in a conductive cylinder, generated from currents passing through a surrounding coil, are studied. The skin effect in the coil is also studied.

Induction Currents from Circular Coils

A time-varying current induces a time-varying magnetic field. The magnetic field induces currents in neighboring conductors. The induced currents are called eddy currents. In this model, the phenomenon is illustrated by a time-harmonic field simulation as well as a transient analysis, where the eddy currents resulting from the source being switched on are studied. Two current-carrying coils ...