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.

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.

Computing the Resistance of a Wire

Every electrical device has some resistance. That is, when a voltage difference is applied across any two terminals of the device, there will be a directly proportional current flow. This model demonstrates how to compute the resistance of a short section of copper wire. The convergence of the solution with respect to the mesh size is also studied.

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.

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 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 ...

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 ...

Capacitive Micromotor

This tutorial shows how to model a 2D capacitive micromotor. The motor consists of a rotor and a stator made of polysilicon. The cogs of the stator are subjected to a time-varying pulsed voltage such that the voltage on adjacent cogs vary by a phase difference of 2p/3. As a result, a time-varying torque acts on the rotor thereby rotating it about its center. This model shows how to use an ...

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.

Simulation of a 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. ...

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.

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