Magnetic Signature of a Submarine
A vessel traveling on the surface or under water gives rise to detectable local disturbances in the Earth’s magnetic field. These disturbances can be used to trigger weapon systems. The magnetic signature of a ship can be reduced by generating a counteracting magnetic field of suitable strength and direction based on prior knowledge of the magnetic properties of the vessel. This model ...
Magnetic Prospecting of Iron Ore Deposits
Magnetic prospecting is a geological exploration method that is applicable to certain types of iron ore deposits, in particular those made up of magnetite and hematite. The method consists of measuring the magnetic anomalies (changes in the earth's magnetic field) due to the presence of magnetic ores. The Magnetic Prospecting app simulates the effect of a deposit of magnetic ore on the earth's ...
Linear Magnetic Gear
In this model, a linear magnetic gear system with a gear ratio of 11:4 is modeled. The liner magnetic gear is assumed to be infinitely long with the modular structure that is repeating on either side. Only a single modular section is modeled by using the customized linear periodic boundary condition. Both the low speed and the high speed armatures (rotors) consist of permanent magnets and back ...
An RFID System
RFIDs are used in a multitude of applications such as tracking or identifying consumer products and their packaging. An RFID system consists of two main parts: A tag or transponder with a printed circuit-board (PCB) antenna A reader unit with a larger RF antennaThe reader antenna generates an electromagnetic field that energizes a chip (IC-circuit) inside the tag. The electromagnetic field ...
Contact Impedance Comparison
The contact impedance boundary condition is meant to approximate a thin layer of material that impedes the flow of current normal to the boundary, but does not introduce any additional conduction path tangential to the boundary. This example compares the contact impedance boundary condition to a full-fidelity model and discusses the range of applicability of this boundary condition.
Magnetic Stiffness of an Axial Magnetic Bearing in 3D
The model illustrate the technique to calculate the magnetic stiffness in a 3D geometry of a permanent magnet axial magnetic bearing. The *Magnetic Fields* physics is used to model the bearing and compute the magnetic forces. The *Deformed Geometry* and *Sensitivity* physics are used to compute the magnetic stiffness. This model is featured and explained in much greater detail in the following ...
Iron Sphere in a 20 kHz Magnetic Field
An iron sphere is exposed to a spatially uniform, sinusoidally time-varying, background magnetic field. The frequency of the field is such that there skin depth is smaller than the sphere radius. The induced currents in the sphere and the perturbation to the background field are computed. Proper meshing of domains with significant skin effect is addressed.
Axial Homopolar Induction Bearing in 3D
This model illustrates the working principle of an axial homopolar induction bearing. An electrically conducting rotor rotating in a magnetic field produced by a permanent magnets induces eddy currents on the conducting rotor. The eddy currents, in turn, produce a magnetic field that opposes the magnetic fields by the magnets and induces a force that opposes the motion of the rotor. The axial ...
Magnetically Permeable Sphere in a Static Magnetic Field
A sphere of relative permeability greater than unity is exposed to a spatially uniform static background magnetic field. Two formulations are used to solve this problem, and the differences between these are discussed. The field strength inside the sphere is computed and compared against the analytic solution.
Electric Shielding Comparison
The electric shielding boundary condition is meant to approximate a thin layer of highly conductive material that provides an additional current path tangential to a boundary. This example compares the electric shielding boundary condition to a full-fidelity model and discusses the range of applicability of this boundary condition.
