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. 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.
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 ... Read More
Transport which is purely diffusive in nature can be modeled using a Brownian force. This model shows how to add such a force in the Particle Tracing for Fluid Flow physics interface. Particle diffusion in a fluid is modeled with the diffusion equation and the Particle Tracing for Fluid ... Read More
This example simulates the separation of particles based on the size in a microchannel using the method of pinched flow fractionation. The microdevice has two inlets and multiple outlets where the velocity field of liquid flow is calculated using the Laminar Flow interface. Then the ... Read More
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 ... Read More
In this benchmark model, solid particles are released in a fully developed turbulent channel flow. The particles are subjected to a drag force that includes contributions from the fluid turbulence, implemented using a Continuous Random Walk (CRW) model. Because the turbulence in the ... Read More
This model computes the transmission probability through an s-bend geometry using both the angular coefficient method available in the Free Molecular Flow interface and a Monte Carlo method using the Mathematical Particle Tracing interface. The computed transmission probability by the ... Read More
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 ... Read More
An electron gun must be able to draw a sufficient current and accelerate the electrons to the desired speed. The first part of an electron gun geometry presents unique design challenges because the emitted electron speeds are usually lowest there, and therefore the space charge density ... Read More
The Free Molecular Flow interface, available in the Molecular Flow Module, is an efficient tool for modeling extremely rarefied gases when the gas molecules move much faster than any geometric entities in the domain. For turbomolecular pumps, in which the blades move at speeds comparable ... Read More
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, ... Read More