Search results for "Magnetic levitation"

Coupled Electromechanical Analysis of a Permanent-Magnet Bearing

2017

In this paper we present a new Permanent Magnets (PMs) bearing, which is composed of a rotor capable to levitate at a short distance from a dedicated stator. Proper configurations of PMs arranged on both the stator and the rotor allows having the magnetic suspension. Intrinsic mechanical instability characterizes the device; a passive stabilization is attempted exploiting eddy currents on a conducting sheet that surrounds the magnets on the stator. The system has been simulated by means of a dedicated numerical code that takes into account the effects of magneto-mechanical coupling. The coupled problem has been integrated by means of a prediction-correction nested scheme. Some interesting r…

UAQ4 Levitating Train: Italian Maglev Transportation System

2014

This article illustrates the University of L'Aquila model 4 (UAQ4) Italian maglev train, a transportation system with zero motion resistance (except aerodynamic drag) and greatly reduced energy consumption, approaching zero at a low constant speed. The project is the result of more than 40 years of research in the field of nonconventional highspeed transportation systems. Its technological feasibility has been tested in the laboratory at the University of L'Aquila, Italy.

Three-dimensional linear stability analysis of the flow in a liquid spherical droplet driven by an alternating magnetic field

2003

The paper presents a numerical stability analysis of the flow driven by an alternating (AC) magnetic field in an electromagnetically levitated liquid metal droplet. The basic axisymmetric flow is found to become unstable at Reynolds numbers in the order of 100. The critical Reynolds number Rec and the corresponding most unstable azimuthal wave number m are found for several configurations of the magnetic field depending on the skin-depth d. For a uniform external AC magnetic field the azimuthal wave number of the most unstable mode is m=3. An additional steady (DC) magnetic field imposed along the axis of symmetry increases the stability of the flow.

Magnetic Levitation – Modelling, Identification and Open Loop Verification

2020

<p>The paper describes a procedure using the first principle modelling and experimental identification of the Magnetic Levitation Model CE 152. It is a modified version of the paper [1]. The difference is that the identification and verification is done in open loop and constraints logic is added in the current paper. The author optimized and simplified dynamic model to a minimum to what is needed to characterize given system for the simulation and control design purposes. Only few open-loop experiments are needed to estimate the unknown parameters. Model quality is verified in open loop where the real and simulated data are compared. The model can serve as a simulation model for some…

Analysis and Design of Induction Liquid Metal Processes Using Advanced Numerical Modelling

2019

Comprehensive knowledge of the turbulent flows, heat and mass transfer processes in the melt of induction applications is required to realize efficient metallurgical processes. Therefore, the process oriented development, design and optimization of induction furnaces for melting and casting of metals require praxis oriented simulation and analysis of the complex in-stationary turbulent melt flows and temperature distributions as well as the heat and mass transfer processes in the liquid metal. The studies, presented in this paper, demonstrate the possibilities of using advanced three-dimensional transient numerical modelling for successful simulation of the melt flow as well as heat and mas…

Large scale electromagnetic levitation melting of metals

2017

'School adopts an experiment': the magnetic levitation of superconductors

2010

The event 'School adopts an experiment' is an event targeted at high schools and secondary schools. It is based on a tight and direct collaboration between researchers and school students and teachers. Several schools were involved in the event by 'adopting' an experiment in physics research laboratories. Groups of selected students were first trained by university researchers, then they demonstrated the experiments to other students and teachers during the event. Students who adopted an experiment acquired knowledge of the subjects connected with the experiment in a most impressive way compared with the usual didactics at school. Further positive points were: (i) to establish a close and d…

Spin-up instability of electromagnetically levitated spherical bodies

2000

Stability of a solid sphere in both uniform and linear alternating magnetic fields is considered with respect to virtual rotations. When the frequency of the alternating magnetic field exceeds a certain critical threshold depending on the configuration of the field, the sphere is found to spin up around a horizontal axis. The physical mechanism of this instability is the same as that of operation of a single-phase induction motor. Sufficiently small rotational disturbances can be completely suppressed by imposing an axial steady magnetic field of strength comparable to that of the alternating field. Nonlinear stability analysis shows that for sufficiently high frequencies, spin-up can be ca…

Application of modulated calorimetry to the Liquid metals using electromagnetic levitation and static magnetic field

2018

Measurement of the thermophysical properties of liquid metals is challenging because of their high chemical activity and high temperatures. The electromagnetic levitation allows one to hold the electrically conductive liquid sample containerless in an inert atmosphere in thermal equilibrium while measurements on the sample can be taken in a non-contact way followed by extraction of some thermophysical properties. Yet, the electromagnetic forces within the skin layer inside the sample cause convective flow of the liquid thus disabling the data extraction. A static magnetic field imposed over a sample is known to damp the convective flow. With these ideas, an experimental set-up with a DC mag…