scholarly journals A Novel Augmented Railgun Using Permanent Magnets

2019 ◽  
Vol 8 (1) ◽  
pp. 99-105
Author(s):  
M. B. Heydari ◽  
M. Asgari ◽  
L. Gharib ◽  
A. Keshtkar ◽  
N. Jafari ◽  
...  

A novel augmented railgun using a permanent magnet is proposed in this paper. The effects of the permanent magnet on the magnetic field and distribution of current density have been investigated. High current densities in the railguns can lead to high local temperature and erosion of the rails. Therefore, the current densities in the rails and armature should be decreased without the reduction of the Lorentz force which is required for acceleration. For this purpose, augmentation of the magnetic field can be used as an effective method. The Finite Element Method (FEM) simulations have been applied in this article to analyze the performance of the railgun in the presence of the magnets. Two augmented railgun structures have been introduced to produce a constant external magnetic field. For both structures, augmented railgun characteristics are studied in comparison to the railgun without the augmentation. The results show that augmentation with permanent magnet increases railgun efficiency, especially in low current railguns. For pulse current source I=30kA, Lorentz force of the augmented railgun with four magnets is 2.02 times greater than the conventional railgun.

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.


2011 ◽  
Vol 24 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Ivan Yatchev ◽  
Krastio Hinov ◽  
Iosko Balabozov ◽  
Kristina Krasteva

Several constructions of electromagnetic actuators with moving permanent magnet for Braille screen are studied. All they are formed from a basic one that consists of two coils, core and moving permanent magnet. The finite element method is used for modeling of the magnetic field and for obtaining the electromagnetic force acting on the mover. The static force-stroke characteristics are obtained for four different constructions of the actuator. The constructions with ferromagnetic disc between the coils ensure greater force than the ones without disc and can reach the required minimum force.


2020 ◽  
Vol 15 (1) ◽  
pp. 150-160
Author(s):  
Kishor Kaphle ◽  
Gyanendra Karki ◽  
Amrit Panthi

 The magnetic field of different geometry of the permanent magnet is analytically calculated by using basic principles of the magnetism in very easier approach. Concept of origin shifting and geometrical shape transformation are used to formulate the formula for cuboidal, cubical and cylindrical permanent magnets. This concept can be used for the analysis of magnetic field distribution in space around for permanent magnet as well as electromagnet in a very easier approach. Handy and simplified software is made to calculate the magnetic field due to permanent magnet and electromagnet at any desired position on space. Magnetic field visualization is also done in both magnitude and direction by using MATLAB.  


2012 ◽  
Vol 271-272 ◽  
pp. 1636-1640
Author(s):  
Xiao Yan Tang ◽  
Zhong Yun ◽  
Chuang Xiang

The calculation model of the single turn rectangle current carrying coil was established. The theoretic formula for calculating the magnetic field intensity of any point in space was derived. For a pair of radial magnetizing permanent magnets, the formula for calculating the magnetic force of permanent magnet in the magnetic field was deduced based on the equivalent current theory of permanent magnet. According to the formula, the influencing factors and the changing rules for the magnetic force of permanent magnet can be seen directly: the current, the coil turns are proportional to its magnetic force, while the coupling distance is inversely proportional to its magnetic force.


Author(s):  
Andrey Morev ◽  
Alexander Aliferov

Purpose The purpose of this paper is to investigate the effect of the rotating magnetic field of permanent magnets on the aluminium melt bath. Design/methodology/approach This model was developed in the ANSYS software package and is based on the application of the finite element method and finite volume. Findings The distribution of the velocity of the melt in a cylindrical vertical bath and the dependence of the maximum value of the melt displacement on the angular rotation velocity of the system of permanent magnets is obtained. Originality/value This work focusses on the interaction of the magnetic field of the moving magnets with the molten metal.


2011 ◽  
Vol 60 (4) ◽  
pp. 413-432
Author(s):  
Krystyn Pawluk ◽  
Renata Sulima

Boundary-integral model of permanent magnet of a tube segment as shape The magnetic field due to a permanent magnet of a tube-side segment as shape and of radial-oriented magnetization is considered. Such a sheet modelling a single pole of the magnet is used to express the suitable contribution to magnetic quantities. A boundary-integral approach is applied that is based on a virtual scalar quantity attributed to the magnet pole. Such an approach leads to express analytically the scalar magnetic potential and the magnetic flux density by means of the elliptic integrals. Numerical examples of the computed fields are given. The general idea of the presented approach is mainly directed towards designing the magnetic field within the air gap of electric machines with permanent magnets as an excitation source. Other technical structures with permanent magnets may be a subject of this approach as well.


2021 ◽  
Vol 4 (3) ◽  
pp. 4-10
Author(s):  
Kamoliddin Oqyolov ◽  
◽  
Nurzod Abduqodirov ◽  
Gulnoza Jalilova ◽  
Nuriddin Abduxakimov

The design of an electric vibrator created on the basis of a linear motor with permanent magnets is considered, and the calculation of the magnetic field and the electromagnetic force acting on the motor armature is performed by the finite element method. The results of experimental studies confirming the reliability of the obtained calculated data are presented]. The purpose of this work is to study the distribution of the magnetic field and the electro-magnetic forces in a coaxial-linear permanent magnet electric motor (PM), which is the basis for the creation of avibration installationKeywords: vibration, magnets, magnetic induction, stator winding, electric vibrator


2013 ◽  
Vol 416-417 ◽  
pp. 264-269
Author(s):  
Pei Long Wang ◽  
Xiao Zhuo Xu ◽  
Bao Yu Du ◽  
Hai Chao Feng ◽  
Xu Dong Wang ◽  
...  

In this paper, two novel topological structures of sliding transformer with ferromagnetic core applied in the Contactless Electrical Power Transmission (CEPT) system used for the ropeless elevator driven by moving-coil type Permanent Magnet Synchronous Linear Motor (PMLSM) have been proposed, and the magnetic field distribution is calculated and analyzed by the finite element method (FEM). According to the analysis results of the traditional E-E topology sliding transformer, much higher coupling coefficients of sliding transformers with proposed topologies have been obtained. Then, based on the magnetic distribution and the circuit model of system, the compensation capacitances have been calculated considering supply frequency and load conditions. Finally, the load characteristic of the system with compensation is also obtained by FEM.


2013 ◽  
Vol 765-767 ◽  
pp. 125-128 ◽  
Author(s):  
Ning Ding ◽  
Ding Tong Zhang ◽  
Yu Mei Song ◽  
Jian Shi ◽  
Li Gong Ding

Based on our proposed superposition principle of the magnetic field, the drive system of parallel moving type and rotation moving type lifting permanent magnet were designed. Industry prototypes were manufactured, respectively, and they verify that the designed lifting permanent magnets are feasible.


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