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.

COMSOL-News-Magazine-2017
COMSOL-News-Magazine-2017-Special-edition-acoustics
COMSOL-News-Magazine-2016

Inertial Focusing Between Two Parallel Walls

For more than 50 years, it has been known that neutrally buoyant particles in a flow channel tend to converge to specific locations in the channel cross section. For a cylindrical pipe, or two parallel planes carrying a Poiseuille flow, the equilibrium position is about 0.6 times the pipe radius, or a distance from parallel walls of about 0.2 times the channel width, respectively. This is called ...

Thermophoresis

When a temperature gradient in a gas exists, suspended particles will tend to move from regions of high temperature to low. The force which produces this effect is called the thermophoretic force. Gas molecules colliding with a particle from the hot side have a higher velocity than the cold side, which results in a net force towards cold areas. This effect can be exploited to create thermal ...

Einzel Lens

An Einzel lens is an electrostatic device used for focusing charged particle beams. It may be found in cathode ray tubes, ion beam and electron beam experiments, and ion propulsion systems. This particular model consists of three axially aligned cylinders. The outer cylinders are grounded, while the cylinder in the middle is held at a fixed voltage. The 3D electrostatic field is computed with ...

Ion Cyclotron Motion

This model computes the trajectory of an ion in a uniform magnetic field using the Newtonian, Lagrangian and Hamiltonian formulations available in the Mathematical Particle Tracing interface.

Laminar Static Particle Mixer Designer

In static mixers, a fluid is pumped through a pipe containing stationary mixing blades. This mixing technique is well suited for laminar flow mixing, because it generates only small pressure losses in this flow regime. When a fluid is pumped through the channel, the alternating directions of the cross-sectional blades mix the fluid as it passes along the length of the channel. The static mixing ...

Thermionic Emission in a Planar Diode

When electrons are emitted from a heated cathode in a plane parallel vacuum diode, they contribute to the space charge density in the diode, which in turn affects the electric potential distribution. If the potential difference between the cathode and the anode is not sufficiently large, a potential minimum forms between them, repelling electrons of insufficient energy back toward the cathode. ...

Ideal Cloak

This model demonstrates the use of optical tracing for studying optically large gradient-index structures with anisotropic optical properties. Additionally, the model introduces a smoothing technique for handling discontinuities of refractive index on curved surfaces, which are typical in conventional optical devices such as lenses.

Quadrupole Mass Filter

A quadrupole mass filter (QMF) is a key component of a modern mass spectrometer. A QMF uses direct current (DC) and alternating current (AC) electric fields to analyze positive or negative ions by mass to charge ratio. A QMF consists of 4 parallel rods spaced equidistantly, the ratio of the rod radius to the radius of the inscribed circle is 1.148. Opposite pairs of rods are electrically ...

Ion Drift Velocity Benchmark

The drift velocity of Ar+ is calculated using a Monte Carlo simulation in which the elastic collisions of Argon ions with ambient neutrals are explicitly modeled. The model uses energy-dependent collision cross-section data from experiment. The average ion velocity values are consistent with experimental data over a wide range of reduced electric field magnitudes. This agreement suggests that ...

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 ...