## Modeling Ferromagnetic Materials in COMSOL Multiphysics®

##### Cesare Tozzo January 23, 2018

Ferromagnetic materials are ubiquitous in electronic components and electrical machinery. In EM modeling, we may be interested in the broader application or focus on a certain material characteristic (e.g., the mechanical resistance of structural steel) that happens to be magnetic. In both cases, ferromagnetic parts influence the magnetic field in their surroundings, and identifying exactly how this happens could be crucial to the proper functioning of a device or system.

### Model Deforming Objects with the Arbitrary Lagrangian-Eulerian Method

##### Edmund Dickinson January 17, 2018

As two of the greatest mathematicians to have ever lived, Leonhard Euler and Joseph-Louis Lagrange made numerous contributions to continuum mechanics. Combining their individual descriptions of the subject inspired the arbitrary Lagrangian-Eulerian (ALE) method, a technique that can be used for a multitude of simulation applications. Find out how the work of Euler and Lagrange helped create the ALE method and how it aids your simulations in the COMSOL Multiphysics® software.

### Modeling Cables in COMSOL Multiphysics®: 6-Part Tutorial Series

##### Brianne Costa December 29, 2017

Want a roadmap to modeling cables? We have a six-part tutorial series for you. The Cable Tutorial Series shows how to model an industrial-scale cable in the COMSOL Multiphysics® software and add-on AC/DC Module, and also serves as an introduction to modeling electromagnetic phenomena in general. The numerical model is based on standard cable designs and validated by reported figures. Keep reading for a sneak peek of what you’ll learn when you roll up your sleeves and start the series.

### Analyzing an Electrodynamic Ion Funnel with COMSOL Multiphysics®

##### Caty Fairclough December 8, 2017

Within mass spectrometers, plasmas are often used to ionize a sample and an inert background gas. Before the ions produced in the plasma are sent into the mass filter, which determines the sample’s chemical composition, they must be focused into a beam with a suitably small radius. One way to focus ions is with an ion funnel. Focusing ions is a critical stage of the overall design, so it’s important to have a fundamental understanding of the funnel’s operating principles.

### Should I Fillet the Geometry in My Electromagnetic Heating Analysis?

##### Walter Frei November 30, 2017

To fillet or not to fillet, that is the question (that can bedevil the multiphysics analyst). When building finite element models, sharp edges can lead to local singularities and fields that are nonconvergent with mesh refinement. Rounding off these sharp edges by adding a fillet avoids this singularity. As it turns out, in many multiphysics models, these sharp edges and the resultant singularities do not necessarily negatively affect the results. Let’s find out more.

### Analyzing Magnetic Flow Meters for Blood Flow Measurement

##### Brianne Costa November 24, 2017

Magnetic flow meters are a noninvasive option for measuring blood flow. However, when patients move, displaced blood vessels can affect the sensitivity of the flow meter. Researchers from ABB Corporate Research used multiphysics modeling to study how the displacement of blood vessels in a moving patient impacts the performance of a magnetic flow meter.

### Analyze the Electrodynamics of a Magnetic Power Switch via Simulation

##### Caty Fairclough September 21, 2017

Have you ever plugged one too many devices into an electrical circuit? This can overload the circuit and damage its components. To avoid this issue, many homes have devices like electric switch circuit breakers to interrupt the current when a critical current is reached. Other types of circuit breakers are used to prevent issues in high-voltage situations, like citywide power lines. In this blog post, we discuss using simulation to study a class of heavy-duty circuit breakers: magnetic power switches.

### How to Create Electrostatics Models with Wires, Surfaces, and Solids

##### Bjorn Sjodin August 8, 2017

The latest version of the AC/DC Module enables you to create electrostatics models that combine wires, surfaces, and solids. The technology is known as the boundary element method and can be used on its own or in combination with finite-element-method-based modeling. In this blog post, let’s see how the new functionality can be used to conveniently set up a model that includes a number of very thin spiral wires.

### Simulating Helmholtz Coils in COMSOL Multiphysics®

##### Bridget Cunningham August 1, 2017

Helmholtz coils are used by scientists to generate uniform magnetic fields to study electromagnetism and its characteristics. These devices are used in MRI, spectroscopy, magnetoresistance measurements, and equipment calibrations. Here, we’ll look at what Helmholtz coils are, why they are important, and using a simulation-based approach to their design.

### How to Calculate a Capacitance Matrix in COMSOL Multiphysics®

##### Sven Friedel June 7, 2017

Capacitance calculations in the COMSOL Multiphysics® software seem easy. If you only have two conductors, the recipe is simple: Take one conductor and set it to grounded, set the other as a terminal, and compute the solution. Then, a built-in variable delivers the capacitance. But what if you have more than two conductors, like in touchscreens, transmission lines, and capacitive sensors? If standard textbook terminology has you lost, follow along with this working example of calculating a capacitance matrix.

### Analyzing the Structural Integrity of an Induction Motor with Simulation

##### Caty Fairclough May 11, 2017

In the 1800s, two scientists — Nikola Tesla and Galileo Ferraris — separately invented their own versions of AC induction motors. Such AC motors turned out to be reliable alternatives to the DC motors that were popular at the time. To accurately study induction motors, we must account for the multiple physics that occur. As today’s example illustrates, we can include the electromechanical effects using the COMSOL Multiphysics® software.