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.


Rat-Race Coupler

A 180° Ring Hybrid (Rat-Race Coupler) is a four-port network with 180° phase difference between two ports. It is cheaper to manufacture this type of microstrip line component compared to a wave guide 180° hybrid junction, so called magic-T. The objective of this model is to compute the S-parameters and to observe the matching, isolation, and coupling around the operating frequency.

Linear Buckling Analysis of a Truss Tower

Trusses are commonly used to create light structures that can support heavy loads. When designing such a structure, it is important to ensure its safety. For a tower made of bars, buckling can cause the structure to collapse. This model shows how to compute the critical buckling load using a linear buckling analysis. The solution is compared with an analytical expression for critical load ...

Relativistic Diverging Electron Beam

When modeling the propagation of charged particle beams at high currents and relativistic speeds, the space charge and beam current create significant electric and magnetic forces that tend to expand and focus the beam, respectively. The *Charged Particle Tracing* interface uses an iterative procedure, in this example, to efficiently compute the strongly coupled particle trajectories and ...

Disc Resonator Anchor Losses

This model shows how to compute the anchor loss limited quality factor of a diamond disc resonator. The resonator is anchored to the substrate by a polysilicon post and power is transmitted to the substrate through the post. A perfectly matched layer is used to represent the essentially infinite substrate. The model is based on a paper presented at the 2007 COMSOL conference in Grenoble: P. ...

Stress Relaxation of a Viscoelastic Tube

This model studies the temperature effects on the viscoelastic stress relaxation in a long thick-walled cylinder. In particular, decay of the stresses under the influence of the temperature field during a period of two hours is studied. A four-term generalized Maxwell model represents the material.

Isoelectric Separation

This example applies the *Electrophoretic Transport* and *Laminar Flow* interfaces to model isoelectric separation in a free-flow electrophoresis device. A stream containing six different ionic species is shown to be divided into pure component streams by means of migrative transport in an electric field. Free-flow electrophoresis can separate macromolecules such as proteins, based on their ...

Ion Energy Distribution Function

One of the most useful quantites of interest after solving a self-consistent plasma model is the ion energy distribution function (IEDF). The magnitude and shape of the IEDF depends on many of the discharge parameters; pressure, plasma potential, sheath width etc. At very low pressures the plasma sheath is said to be collisionless, meaning that the ion energy is not retarded by collisions with ...

Homopolar Generator 3D

A homopolar generator is composed of an electrically conductive rotating disc placed in a uniform magnetic field that is perpendicular to the plane of rotation. The motion of the conductor through the static magnetic field induces Lorentz currents in the disc. By connecting the outside rim of the disc to the center via a stationary conductor, significant current can be generated. The flow of ...

Glazing Influence on Thermal Performances of a Window

During the design of a building, environmental issues have gained considerable influence in the entire project. One of the first concerns is to improve thermal performances. In this process, simulation software are key tools to model thermal losses and performances in the building. The international standard ISO 10077-2:2012 deals with thermal performance of windows, doors and shutters. It ...

Optimization of a Catalytic Microreactor

In this application, a solution is pumped through a catalytic bed where a solute species reacts as it gets in contact with the catalyst. The purpose of this example is to maximize the total reaction rate for a given total pressure difference across the bed by finding an optimal catalyst distribution. The distribution of the porous catalyst determines the total reaction rate in the bed. A large ...