## How to Model Electrodynamic Magnetic Levitation Devices

##### Nirmal Paudel November 28, 2016

Electrodynamic magnetic levitation can occur when there are time-varying magnetic fields in the vicinity of a conductive material. In this blog post, we will demonstrate how to model this principle with two examples: a TEAM benchmark problem of an electrodynamic levitation device and an electrodynamic wheel.

### How to Analyze an Induction Motor: A TEAM Benchmark Model

##### Nirmal Paudel July 18, 2016

In this blog post, we work through the three-phase induction motor described in Testing Electromagnetic Analysis Methods (TEAM) workshop problem 30a. We analyze the induction motor in 2D using the transient solver in the Rotating Machinery, Magnetic interface. We investigate the motor’s start-up dynamics by coupling the electromagnetic analysis with the rotor dynamics, including the inertial effects. At the end, we compare the benchmark model’s results with those from the COMSOL Multiphysics simulation.

### Part 2: Model a Linear Electromagnetic Plunger with a Blocker

##### Nirmal Paudel June 14, 2016

In the previous part of our Electromagnetic Device series, we showed you how to model a linear electromagnetic plunger attached to a spring and damper and compute the position, velocity, and electromagnetic forces. Here, we will demonstrate an actuator that includes a blocker/stopper to restrict linear motion. We will also discuss how to model the contact and release of this actuator using the Events, Magnetic Fields, Moving Mesh, and Global ODEs and DAEs interfaces.

### Part 1: How to Model a Linear Electromagnetic Plunger

##### Nirmal Paudel June 7, 2016

An electromagnetic plunger is an electromechanical device that converts electrical energy into a linear mechanical motion. This motion can be used to move an external load such as closing electromagnetic valves and closing or opening electromagnetic relays. In this blog post, we introduce a procedure to model the behavior and dynamics of an electromagnetic plunger that consists of a multi-turn coil, magnetic core, nonmagnetic guider, and magnetic plunger.

### Modeling Magnetic Gears in COMSOL Multiphysics

##### Nirmal Paudel April 26, 2016

Magnetic gears are the contactless mechanisms for torque-speed conversion using permanent magnets or electromagnets. They are utilized in several renewable energy applications, increasing the speed of wind energy, ocean energy, and flywheel energy storage in order to match the specification of the electromagnetic generator. Unlike their mechanical counterparts, magnetic gears offer inherent overload protection, have high reliability due to frictionless operation, and require no lubrication. Today, we’ll discuss how to simulate magnetic gears in 2D and 3D with COMSOL Multiphysics.

### Guidelines for Modeling Rotating Machines in 3D

##### Nirmal Paudel February 18, 2016

In a previous blog entry, we showed you how to model rotating machines, like motors and generators, using the Rotating Machinery, Magnetic interface in COMSOL Multiphysics. Today, we will demonstrate the steps we outlined with a 3D generator model example, comparing our results with an analogous 2D model. The concepts of sector symmetry and periodic boundary conditions, including examples illustrating their use, are also highlighted.

### Model Magnetic Materials in the Frequency Domain with an App

##### Nirmal Paudel January 7, 2016

The nonlinear magnetic saturation curves in the AC/DC Module’s Nonlinear Magnetic Materials Database can now be used in frequency-domain simulations using COMSOL Multiphysics version 5.2. You can now convert the associated B-H or H-B curve, which was previously supported only for stationary and time-dependent studies, into an effective B-H or H-B curve using the newly added Effective Nonlinear Magnetic Curves Calculator app. In this blog post, we will discuss how this app is used in frequency-domain simulations.

### Modeling Linear Motors or Generators in COMSOL Multiphysics

##### Nirmal Paudel October 6, 2015

The Rotating Machinery, Magnetic physics interface available in the AC/DC Module is used to model rotating machines such as motors or generators. When modeling the linear or tubular device with the Magnetic Fields and the Moving Mesh physics interfaces, it is appropriate to use a customized linear periodic boundary condition. In this blog post, we will explore how to customize the linear periodic boundary condition and model the tubular generator that is used for wave energy.