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.

Underground medium voltage cables are often used to deliver electrical power from a transmission system and into the home of consumers. In the United Kingdom, these cables carry hundreds of amps at voltages between 11 and 33 kV, a typical voltage of electrical transmission cables around the world. Analyzing the stresses that these cables are exposed to over their lifetime is important for ensuring both consumer safety and energy efficiency. Researchers from the Glasgow Caledonian University in Scotland used COMSOL […]

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.

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.

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.

A contact switch is used to regulate whether or not an electrical current is passing from a power source and into an electrical device. These switches are found in many types of equipment and they are used to control, for example, the power output from a wall socket into a device when it is plugged in; the currents passing across the circuit board of a computer; or the electricity powering a light bulb when the switch is flipped on. Because of their […]

Our day-to-day lives are dependent on the safety of technical systems and processes. We blindly trust that reactor vessels withstand the test of time, that the train or ship we’re on does not break down. These metal structures, in turn, rely on accurate welding processes. Here’s where BAM Federal Institute for Materials Research and Testing comes into the picture. BAM researchers have been working on improving upon the high-power laser beam welding process in order to promote safer and more […]

When given the choice, we’d all prefer our loudspeakers to project perfect sound; having a phone conversation with someone who sounds like a robot caught in a windstorm is less than ideal. The quality of the sound is, naturally, dependent on how well the speaker is designed, and COMSOL Multiphysics is the perfect tool to simulate and optimize loudspeaker designs because of its easy-to-use multiphysics nature. For a loudspeaker analysis to be accurate, you must be able to simulate from […]

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.

Last week you saw how you can simulate the heating of a car’s brake discs. This reminded me of another type of brake — the eddy current brake (also known as magnetic brake). Whereas the other model was a study in heat transfer, eddy current brakes deal with electromagnetics.