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Showing papers on "Magneto published in 2017"




Journal ArticleDOI
TL;DR: In this paper, the elastic and damping properties of MSE containing magnetically soft particles under the influence of a uniform magnetic field were investigated and the first eigenfrequency of free bending vibrations of a fixed beam was evaluated theoretically and numerically using Finite Element Method.

49 citations


Journal ArticleDOI
01 Jan 2017
TL;DR: In this article, the original formulation of the quasi-3D sinusoidal shear deformation plate theory was extended to the wave propagation analysis of viscoelastic sandwich nanoplates considering surface properties.
Abstract: The original formulation of the quasi-3D sinusoidal shear deformation plate theory (SSDPT) is here extended to the wave propagation analysis of viscoelastic sandwich nanoplates considering surface ...

40 citations


Journal ArticleDOI
TL;DR: In this paper, an analytical design methodology of three-phase permanent magnet machines (FRPMMs) is presented, where the sizing equations are derived based on a magneto motive force permeance model and the influences of several key parameters in the sizing equation, including slot-pole combination, airgap radius, electric loading, and equivalent magnetic loading on the torque density, are analyzed.
Abstract: Flux reversal permanent magnet machines (FRPMMs) exhibit many advantages such as simple rotor configuration, high torque density, fast transient response, etc. However, the general analytical design procedure of FRPMMs has not been established. Thus, this paper mainly focuses on developing an analytical design methodology of three-phase FRPMMs. First, the sizing equations are derived based on a magneto motive force-permeance model. Then, the influences of several key parameters in the sizing equation, including slot-pole combination, airgap radius, electric loading, and equivalent magnetic loading on the torque density, are analyzed. Moreover, the feasible slot-pole combinations are summarized and the corresponding winding type of each combination is recommended in order to maximize the output torque. Additionaly, the detailed geometric design of stator and rotor is presented. Finally, the proposed analytical design procedure is verified by finite element analysis and experiments on a 12-stator-slot/17-rotor-slot FRPMM prototype.

39 citations


Journal ArticleDOI
TL;DR: In this paper, the authors present results from a global MHD simulation of solar convection in which the heat transported by convective flows varies in-phase with the total magnetic energy, and carry out an analysis of the entropy and momentum equations to uncover the physical mechanism responsible for the enhanced heat transport.
Abstract: We present results from a global MHD simulation of solar convection in which the heat transported by convective flows varies in-phase with the total magnetic energy. The purely random initial magnetic field specified in this experiment develops into a well organized large-scale antisymmetric component undergoing hemispherically synchronized polarity reversals on a 40yr period. A key feature of the simulation is the use of a Newtonian cooling term in the entropy equation to maintain a convectively unstable stratification and drive convection, as opposed to the specification of heating and cooling terms at the bottom and top boundaries. When taken together, the solar-like magnetic cycle and the convective heat flux signature suggest that a cyclic modulation of the large-scale heat-carrying convective flows could be operating inside the real Sun. We carry out an analysis of the entropy and momentum equations to uncover the physical mechanism responsible for the enhanced heat transport. The analysis suggests that the modulation is caused by a magnetic tension imbalance inside upflows and downflows, which perturbs their respective contributions to heat transport in such a way as to enhance the total convective heat flux at cycle maximum. Potential consequences of the heat transport modulation for solar irradiance variability are briefly discussed. Subject headings: Solar convection, magnetohydrodynamics, solar irradiance

34 citations


Journal ArticleDOI
TL;DR: In this article, a coupled magneto-electro-mechanical (MEM) lumped parameter model for the response of the proposed MEE energy harvesting systems under base excitation is presented.
Abstract: The objective of this paper is to present a coupled magneto-electro-mechanical (MEM) lumped parameter model for the response of the proposed magneto-electro-elastic (MEE) energy harvesting systems under base excitation. The proposed model can be used to create self-powering systems, which are not limited to a finite battery energy. As a novel approach, the MEE composites are used instead of the conventional piezoelectric materials in order to enhance the harvested electrical power. The considered structure consists of a MEE layer deposited on a layer of non-MEE material, in the framework of unimorph cantilever bars (longitudinal displacement) and beams (transverse displacement). To use the generated electrical potential, two electrodes are connected to the top and bottom surfaces of the MEE layer. Additionally, a stationary external coil is wrapped around the vibrating structure to induce a voltage in the coil by the magnetic field generated in the MEE layer. In order to simplify the design procedure of the proposed energy harvester and obtain closed form solutions, a lumped parameter model is prepared. As a first step in modeling process, the governing constitutive equations, Gauss's and Faraday's laws, are used to derive the coupled MEM differential equations. The derived equations are then solved analytically to obtain the dynamic behavior and the harvested voltages and powers of the proposed energy harvesting systems. Finally, the influences of the parameters that affect the performance of the MEE energy harvesters such as excitation frequency, external resistive loads and number of coil turns are discussed in detail. The results clearly show the benefit of the coil circuit implementation, whereby significant increases in the total useful harvested power as much as 38% and 36% are obtained for the beam and bar systems, respectively.

34 citations


Journal ArticleDOI
TL;DR: In this article, a simplified multiscale approach and a Helmholtz free energy based approach for modeling the magneto-mechanical behavior of electrical steel sheets are compared.

31 citations



Journal ArticleDOI
TL;DR: In this paper, the effects of nanoparticles on the entropy generation of steady magnetohydrodynamic incompressible flow with viscous dissipation and Joule heating through convergent-divergent channel are analyzed.
Abstract: The effects of Cu-nanoparticles on the entropy generation of steady magnetohydrodynamic incompressible flow with viscous dissipation and Joule heating through convergent-divergent channel are analysed in this paper. The basic nonlinear partial differential equations are transformed into a system of coupled ordinary differential equations using suitable transformations which are then solved using power series with Hermite- Padé approximation technique. The velocity profiles, temperature distributions, entropy generation rates, Bejan number as well as the rate of heat transfer at the wall are presented in convergent-divergent channels for various values of nanoparticles solid volume fraction, Eckert number, Reynolds number and channel angle. A stability analysis has been performed for the shear stress which signifies that the lower solution branch is stable and physically realizable, whereas the upper solution branch is unstable. It is interesting to remark that the entropy generation of the system increases at the two walls as well as the heat transfer irreversibility is dominant there whereas the fluid friction irreversibility is dominant along the centreline of the channel.

18 citations



Journal ArticleDOI
TL;DR: In this article, a 1D magneto-granular phononic crystal composed of a chain of steel spherical beads on top of permanent magnets was designed and operated for the first time.


Journal ArticleDOI
04 Aug 2017-Energies
TL;DR: In this paper, a hybrid magnetic coupler based on soft start was proposed to solve the problem of large vibro-impact from the cutting unit of the hard rock tunnel boring machine (TBM).
Abstract: Specific to a problem of large vibro-impact aris ing from the cutting unit of the hard rock tunnel boring machine (TBM), a hybrid magnetic coupler based on soft start was proposed in this paper. The mathematical model for total eddy current losses of such a coupler was established by field-circuit method. Then, magnetic-thermal coupling simulation was performed by virtue of three-dimensional finite element software. In addition, an experimental prototype was independently designed; by comparing the model with experimental data, validity of the above mathematical model was verified. The relevant research results indicated that calculated values were consistent with experimental values, and the magneto thermal coupling method could be applied to accurately analyze temperature distribution of the hybrid magnetic coupler. By contrast to the existing magnetic coupling of the same dimension, output efficiency of the hybrid magnetic coupler was improved by 1.2%. Therefore, this research technique can provide references for designing the cutting unit of hard rock TBM with a high start impact.

Journal ArticleDOI
TL;DR: In this article, a finite volume based three dimensional numerical analysis is performed on the effect of angle of inclination of the external magnetic force on entropy generation due to natural convection inside the cubical cavity filled with CNT water nanofluid.
Abstract: A finite volume based three dimensional numerical analysis is performed on the effect of angle of inclination of the external magnetic force on entropy generation due to natural convection inside the cubical cavity filled with CNT water nanofluid. The governing equations are numerically solved by vorticity vector potential formalism. The vertical walls of enclosure are differentially heated and the horizontal walls are adiabatic. The effect due to Rayleigh number (103 ≤ Ra ≤ 105), Hartmann number (0 ≤ Ha ≤ 100), angle of inclination of external magnetic field (0° ≤ α ≤ 90°) and volumetric fraction (0 ≤ φ ≤ 0.05) of CNT particles are investigated. The results of irreversibility process with single phase model are illustrated with entropy generation and Bejan number. The effect of angle of inclination is more pronounced when Rayleigh number is 105.

Journal ArticleDOI
TL;DR: In this article, a magneto-mechanical device was designed, manufactured and thoroughly characterized in terms of field parameters and magnetic nanoparticle properties, in which different magnetic field configurations were established by orderly arrangements of commercial Nd-Fe-B permanent magnets.



Journal ArticleDOI
TL;DR: In this paper, a smart sandwich structure with controllable dynamic properties is presented, without compromising the main characteristics of conventional thin visco-coated sandwich structures, and it is shown how to obtain a smart-sandwich structure with dynamic properties.
Abstract: This study’s relevance lies in the possibility of obtaining a smart sandwich structure with controllable dynamic properties, without compromising the main characteristics of conventional thin visco...

Journal ArticleDOI
TL;DR: A new kinetically consistent method for the modelling of magneto gas dynamic processes is proposed that is consistent with viscous, thermally conducting, resistive flows and robust in resolving the physical behaviour of shock structures and instabilities.




Journal ArticleDOI
01 Aug 2017
TL;DR: In this paper, the effects of Hall current on natural convective flow of radiative, incompressible, viscous and electrically conducting magneto-nanofluid over a uniformly accelerated moving vertical ramped temperature plate in a rotating medium have been analyzed.
Abstract: Present research work has been undertaken to analyze the effects of Hall current on natural convective flow of radiative, incompressible, viscous and electrically conducting magneto-nanofluid over a uniformly accelerated moving vertical ramped temperature plate in a rotating medium. Three types of water based nanofluids containing the nanoparticles of alumina, copper and titanium oxide have been accounted. The mathematical model of the problem has been presented using the nanoparticle volume fraction model. The Laplace transform technique has been employed to solve the mathematical model. The closed-form expressions of nanofluid velocity, temperature, shear stress and rate of heat transfer at the plate have been obtained for both the conditions of ramped temperature and isothermal plates. The effects of various physical parameters on the nanofluid velocity due to primary and secondary flows and temperature have been exemplified using various graphs whereas, the numerical values of shear stress and rate of heat transfer at the plate have been reported in tabular form for different values of physical parameters of interest. Moreover, the numerical results have been compared for the natural convective flow near ramped temperature plate with the corresponding flow near isothermal plate. It has been noted that both the nanofluid velocity and temperature are higher in magnitude in the case of isothermal plate than that of ramped temperature plate. The results of present research work have been validated with the earlier published work.

Journal ArticleDOI
TL;DR: In this paper, a double pulse current generator (Qin-1) was used to suppress the core-corona structures and its ablation using a novel Z-pinch generator.
Abstract: Suppressing of the core-corona structures shows a strong potential as a new breakthrough in the X-ray power production of the wire array Z-pinches. In this letter, the demonstration of suppressing the core-corona structures and its ablation using a novel double pulse current generator "Qin-1" facility is presented. The "Qin-1" facility coupled a ~10 kA 20 ns prepulse generator to a ~ 1 MA 170 ns main current generator. Driven by the prepulse current, the two aluminum wire array were mostly heated to gaseous state rather than the core-corona structures, and the implosion of the aluminum vapors driven by the main current showed no ablation, and no trailing mass. The seeds for the MRT instability formed from the inhomogeneous ablation were suppressed, however, the magneto Rayleigh-Taylor instability during the implosion was still significant and further researches on the generation and development of the magneto Rayleigh-Taylor instabilities of this gasified wire array are needed.





Journal ArticleDOI
TL;DR: A magneto-optic sensing system based on the "off-axis" optical probing technique to control the measurement sensitivity of magnets with various field strengths and a wide dynamic range with good responsivity and low probe invasiveness against the magnetic field being measured.
Abstract: We present a magneto-optic sensing system based on the "off-axis" optical probing technique to control the measurement sensitivity of magnets with various field strengths. The magnetic field is experimentally investigated in the absolute scale through a photonic calibration method with a standard electromagnet. Our all-dielectric magnetic field probe has a wide dynamic range (20 mT-3 T) with good responsivity and low probe invasiveness against the magnetic field being measured. Utilizing this magnetic-field-calibrated probing system, we obtain the magnetic field distribution of permanent magnets. Subsequently, we compare our results with numerical analyses to confirm the effectiveness of the probing system. Finally, we measure the intense magnetic field inside the bore of a 3.0-T clinical magnetic resonance imaging system with our probe.