AC/DC

Alexandra Foley | April 23, 2014

Magnetic fields are fundamental forces in the universe. Without them, planetary orbits, electricity, and elementary particles could not exist. Helmholtz coils are used by scientists to generate uniform magnetic fields to study electromagnetism and its characteristics. They are used in MRI, spectroscopy, magnetoresistance measurements, and equipment calibrations. Here, we’ll look at what Helmholtz coils are, why they are important, and how can they be modeled.

Read more ⇢

Article Categories

Mark Fowler | March 21, 2014

When designing magnets, you want to save resources by using as little material as possible, while generating as large of a force as possible on the object in question. To calculate the force of a one-sided magnet, you can use COMSOL Multiphysics and the AC/DC Module.

Read more ⇢

Article Categories

Marc Fernandez Silva | March 5, 2014

Being able to compute the spatial gradients of the magnetic field or magnetic flux density is needed in areas such as radiology, magnetophoresis, and geophysics. One of the most important applications is in the design of magnetic resonance imaging machines, where it’s important to analyze not only the field strength, but also the spatial variation of the field. Today’s blog will demonstrate how to compute and plot the gradients of the magnetic field in 3D electromagnetic simulations in COMSOL Multiphysics.

Read more ⇢

Article Categories

Mark Fowler | February 24, 2014

Submarines can be detected by enemy weapon systems due to their magnetic signatures. By designing vessels with reduced magnetic signatures, detection can be avoided, but the composition and size of most submarines often make simulation difficult. COMSOL software helps you overcome this problem.

Read more ⇢

Article Categories

Fanny Littmarck | January 3, 2014

Before conducting certain blood sample analyses, researchers need to separate the red blood cell particles from the blood plasma. Using lab-on-a-chip (LOC) technology, red blood cell separation can be achieved via magnetophoresis, i.e. motion induced by magnetic fields. Since the magnetic permeability of the particles is different from the blood plasma, their trajectory can be controlled within the flow channel of the LOC device and thereby separated out from the fluid.

Read more ⇢
Magnus Olsson | December 2, 2013

When designing inductive devices, both challenges and possibilities are associated with the nonlinear behavior of ferromagnetic materials. COMSOL Multiphysics is well-adapted to the solution of highly nonlinear numerical models but high-fidelity modeling of nonlinear inductive devices also requires accurate material data. To meet this challenge, a library of 165 nonlinear magnetic materials is provided in COMSOL 4.4, bringing new powers to the design and modeling of electric motors, transformers, relays, etc. Here, we will discuss how the modeling process is […]

Read more ⇢

Article Categories

Supratik Datta | August 26, 2013

If you have ever stood next to a transformer, you have probably heard a humming sound coming from it and wondered if there were bees close by. When you hear that sound the next time, you can rest assured that it’s not bees but the magnetostriction of the transformer core that is making that humming sound.

Read more ⇢
Fanny Littmarck | June 21, 2013

I’ve written several blog entries involving permanent magnets, in one way or another. Reading those may have raised the question “what about a more simple introduction to permanent magnet simulations?” Fair enough, here’s how to model a permanent magnet and its surrounding magnetic field.

Read more ⇢

Article Categories

Walter Frei | April 2, 2013

A question that comes up occasionally is whether or not you can compute the inductance of a single straight wire. This seemingly simple question actually does not really have an answer, and gives us the opportunity to talk about a very interesting point when solving Maxwell’s equations. Anybody working in the field of computational electromagnetics should have an understanding of this key concept, as it will help you properly set up and interpret models involving magnetic fields.

Read more ⇢

Article Categories

Fanny Littmarck | April 1, 2013

In the world of bearings, there are many different types to choose from. For certain applications, magnetic bearings trump their mechanical counterparts in several regards. In order to understand how the bearing will perform, using a simulation tool to calculate design parameters is a good idea.

Read more ⇢

Article Categories

Daniel Smith | March 27, 2013

In a previous blog entry I discussed some of the exotic properties of graphene. The fact that graphene consists of a single layer of atoms means the aspect ratio of any graphene-based structure may be very high. High aspect geometries present their own array of modeling challenges.

Read more ⇢