bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimentally validated residual stresses and distortion prediction for dual frequency induction hardening
Authors: Schwenk M. , Hoffmeister J. , Schulze V.
Published: December 2018

Dual frequency induction hardening can be a low distortion alternative to case hardening for gearings. However, profound process understanding is still lacking, which is reflected by the absence of appropriate models allowing the prediction of final component properties in terms of residual stresses and distortion. In order to close this gap, a 2-D numerical model has been developed, considering short time austenitization kinetics of quenched and tempered AISI 4140. The induction heating model considering the nonlinear magnetic material behaviour is realized with MSC.Marc®, whereas the mechanical response is implemented in Abaqus/Standard®. The comparison of residual stresses and distortion with experimental results shows that the developed model is in good agreement. Numerical investigations have shown that the core temperature and the TRIP strain during the martensitic transformation will determine the quantitative distribution of the residual stresses.
Modeling of fully coupled mhd flows in annular linear induction pumps
Authors: Roman C. , Dumont M. , Letout S. , Courtessole C. , Vitry S. , Rey F. , Fautrelle Y.
Published: December 2018

The paper studies specific pumping characteristics of the Annular Linear Induction Pumps (ALIP) with travelling field for liquid sodium. The present work is focused on the analysis of very large electromagnetic pumps able to provide high flow rates. The magnetic Reynolds number is quite large, therefore, it is necessary to take into account the full magnetohydrodynamic interaction between the electromagnetic field and the liquid metal flow inside pump channel. We couple the electromagnetic aspects with the hydrodynamic ones by means of two commercial softwares. The geometry considered here is 2D axisymmetric. It is found that in such induction pumps the effect of convection is very important. Two main effects have been put forth. Firstly, due to the magnetic entrainment significant end effects are observed for large velocities. This leads to the existence of regions where the axial force is negative. Secondly, a Hartmann effect occurs near the walls. The electric current and the corresponding forces are confined near the wall in Hartmann layers. Global stability of e.m. pump is also analysed.
Sizing optimization of piezoelectric smart structures with meta-modeling techniques for dynamic applications
Authors: Pommier-Budinger Valerie , Budinger Marc
Published: December 2018

This article shows an efficient method with a high industrial applicability to design piezoelectric smart structures for dynamic applications. This method allows sizing structures with requirements of dynamic displacements. The first step of this method consists in extracting dynamic reduced models from Finite Element simulations which will enable us to obtain a model for any structure, whatever its complexity, as opposed to analytical modeling methods. These models are computed for a set of design parameters. Then a meta-model, which is a simplified descriptive model of other models, is computed as a surface response model that expresses the design objectives and constraints as a function of the design variables. The combination of the results stemming from the meta-model allows working out the optimal values of the design parameters. The main advantage of the proposed method is to enable the quick design exploration of structures. As an example, the method is applied to a flexible structure whose dynamic displacements need to be controlled in bending and twisting. The theoretical results are validated in the end by experiments.
Optimization design of low-speed surface-mounted PMSM for pumping unit
Authors: Cui Junguo , Xiao Wensheng , Wang Longhua , Feng Hao , Zhao Jianbo , Wang Hongyan
Published: December 2018

Efficiency and torque ripple are usually especially concerned during the working process of permanent magnet synchronous motor (PMSM). The loss and cogging torque generated during the working process of PMSM are analyzed. A low-speed surface-mounted PMSM used for direct-drive pumping unit is optimized. For increasing efficiency and reducing cogging torque, Taguchi's method is employed and height of stator yoke, width of stator tooth, thickness of permanent magnet, and air-gap length are selected as the variables. The orthogonal experiment is conducted with FEM. The mean of the results and the two-order interaction effects between the selected variables are analyzed, then the best optimization combination is determined by the analysis of variance. The results show that Taguchi's method is an efficient and effective approach, which is finally proved by the prototype test.
Analysis of the magnetic field created by permanent magnet rings in permanent magnet bearings
Authors: Bekinal Siddappa Iranna , rao Anil Tumkur Ramakrishna , Jana Soumendu
Published: December 2018

This paper presents a simple mathematical model to determine the three dimensional (3D) magnetic field components in Permanent Magnet (PM) bearings made of ring magnets with axial, radial and perpendicular polarizations. MATLAB codes are written to evaluate the magnetic field components using Coulombian model and simple vector approach. In addition, the effect of axial, radial and angular displacements (five degrees of freedom) of the rotor magnet ring on the magnetic field created by the ring magnets in PM bearings is presented. Finally, the effect of movement of the outer ring magnet on the magnetic field created by two rings in the air gap is discussed.
Experimental and theoretical analysis of metal magnetic memory signals in the stress concentration area of 45# steel under tensile testing
Authors: Su Hao , Chen Ming
Published: December 2018

Tension tests were conducted on 45# steel to investigate metal magnetic memory in stress concentration areas. The normal and tangential components of metal magnetic memory signals at seven test points in each specimen were simultaneously measured with probe lift-off values of 1 mm, 3 mm, and 5 mm. Axial tensile load was applied until visible necking occurred, and magnetic flux density was compared with the fracture location predicted according to Doubov's theory. Experimental results showed that the final fracture locations were inconsistent with the locations predicted by metal magnetic memory testing theory. A theoretical analysis of the determination criterion in Doubov's theory also revealed that no perfect correlation between the two areas existed.
Mutual inductance calculation between arbitrarily positioned rectangular filaments
Authors: Cheng Yuhua , Shu Yaming
Published: December 2018

The mutual inductance between the transmitted and received coils is an important parameter in the inductively coupled wireless power transmission system. The relative position between the linked coils may be arbitrary according to the applications. In this paper the analytical calculation of the mutual inductance between two arbitrarily positioned rectangular filaments is proposed based on a more general expression of mutual inductance calculation of two arbitrarily positioned straight filaments than Grover's. The calculation results are validated by using the finite element simulation tools. The previous published approximation methods for square coils in the coaxial, lateral misalignment or angular misalignment situations are verified that they are accurate when the two coils' relative distances are large.
Analysis of the eddy force disturbance on foil-wound coils in magnetic levitated planar motion
Authors: Zhou Rougang , Zhou Yunfei , Liu Guangdou , Lu Jianyin , Cheng Xin
Published: December 2018

Magnetically levitated planar actuators can simplify the planar motion mechanism and thus realize high-speed and high-accuracy motion. The accuracy in the shape of coil, a core part of magnetically levitated planar actuator, is crucial to the performance of actuator. Although the foil-wound coil has high forming precision, the strong eddy current generated in the motion of actuator may pose great interference to magnetic levitation and deteriorate system stability. Based on a thorough analysis of the eddy current and eddy-current force of foil-wound coils in the magnetically levitated planar motion, the paper proposes the calculation model for disturbing eddy force. Results from the simulation show that the model has a relatively high accuracy. It is also indicated that further predictive compensation for the eddy force in the control of precise magnetically levitated actuators can increase the kinematic accuracy and stability of magnetically levitated planar motion system.
The drying efficiency of electrohydrodynamic (EHD) systems based on the drying characteristics of cooked beef and mathematical modeling
Authors: Ding Changjiang , Lu Jun , Song Zhiqing , Bao Siqingaowa
Published: December 2018

The aim of this work is to select the most suitable mathematical model to describe the thin layer electrohydrodynamic (EHD) drying of cooked beef based on voltage and such geometrical characteristics as thickness and cross-sectional area of the material. To accomplish this, the EHD drying technique was employed at 0 kV, 6 kV, 14 kV, 21 kV and 32 kV for alternating current (AC). The drying temperature was 21 ± 2°C, and the drying relative humidity was 30± 5%, while the ambient wind speed was 0 m/s. Samples of cooked beef of different thickness and cross-sectional area were put into a high voltage electric field at 24 kV for AC. Six different mathematical drying models were then compared to simulate drying curves based on root mean square error, reduced mean square of deviation and modeling efficiency. The results showed that the drying rate of cooked beef was notably greater in the EHD system when compared to control. Both thickness and cross-sectional area of cooked beef had more impact on drying rate during the first half hour, and the Demir et al. model was the best mathematical model. Therefore, this work provides guidance for optimizing and improving the drying efficiency of EHD.
Magnetostrictive deformation of a transformer: A comparison between calculation and measurement
Authors: Ghalamestani Setareh Gorji , Vandevelde Lieven , Dirckx Joris J.J. , Guillaume Patrick , Melkebeek Jan A.A.
Published: December 2018

Magnetostriction, which refers to the deformation of the core material of transformers and electrical machines, is a main contributor to the total noise. In this work, a technique is proposed to calculate the magnetostrictive deformations of the core of the aforementioned devices. This technique is based on finite element approach with an artificial neural network model of the magnetostrictive behaviour of the core material. The strain measurements are carried out by using a dual heterodyne laser interferometer setup. The proposed technique is then applied to a single-phase test transformer core.

As a validation, the vibration of the magnetised core of the same setup is measured by using a laser scanning vibrometer.
Stress evaluation in non-oriented electrical steel samples by observation of vector magnetic flux under static and rotating field conditions
Authors: Psuj Grzegorz , Chady Tomasz , Enokizono Masato , Todaka Takashi
Published: December 2018

In this paper influence of uniaxial stress loading on local changes of magnetic properties in a non-oriented silicon steel was examined. The measurements were carried out for different direction of loading force in respect to the rolling direction of the steel. Impact of the relationship between the rolling and the loading direction on evaluation of magnetic properties changes caused by stress was investigated using samples cut out at three different angles from the steel sheet. During the experiments two types of transducers with two and three sensitivity axes operating under rotating AC and static DC field were utilized. First, the observation of local changes of parameters related to a vector magnetic flux was carried out. Then algorithms of measured signals parameterization were utilized and evaluation of the stress distribution in tested samples was proceeded. Finally, the statistical analysis of computed signals parameters was applied and the correlation with stress-strain curve was assessed.
2D nonlinear electrical model of a ferrite inductor which reproduces saturation and power losses in its core
Authors: Salas Rosa Ana , Pleite Jorge
Published: December 2018

We propose a model of an equivalent electrical circuit specifically designed for a ferrite inductor excited by a nonsinusoidal waveform valid for use in an electronic circuit simulator. We estimate the model parameters by means of Finite Elements in 2D which leads to significant computational advantages over the 3D model. We carry out the validation of the procedure for an RM14/I core by comparing the experimental and simulated output waveforms obtained at different frequencies and levels of excitation from the linear to the saturation regions. In addition, we consider the effect of power losses in the core.
Domain reconstructions of g.o. SiFe during rotational magnetization considering also 3-D flux components
Authors: Galabov Viktor , Pfützner Helmut , Shilyashki Georgi , Yamaguchi Hiroi , Okazaki Yasuo , Arai Satoshi
Published: December 2018

Domain analyses of modern types of grain-oriented (GO) transformer steel are rare, and they are focussed on single grains under academic magnetization patterns. The present Kerr effect study reveals that grains of industrial, polycrystalline materials react in specific ways according to individual crystallographic orientations. The amount of parameters is very large, especially if additional flux components are given as a further impact. The paper reports a procedure for statistical evaluations of quasi-dynamic Kerr effect images. The instantaneous area ratios of bar domain portion BD, oblique domain portion OD and saturation S are determined with consideration of peak induction B_{RD} in the rolling direction (RD), axis ratio a of rotational magnetization, the angle ψ between B and RD, additional flux B_x in RD or B_z in normal direction. Focus is put on OD(t) which is assumed to be a key function for λ (t), i.e. the course of time of magnetostriction. As the most distinct tendencies, OD increases strongly with increases of a and ψ. OD(t) shows non-sinusoidal course of time with differences of the two halves of cycle. Rotation out of the RD yields sharp onsets of ODs, especially after half-cycle saturation. Additional off-plane flux enhances ODs in a general way.
Static magnetic fields to liquid bridges: A numerical study
Authors: Liang Ruquan , Yang Shuo , Yan Fusheng
Published: December 2018

A mathematical model is developed with an interest to examine the effects of the transverse magnetic field on the thermocapillary convection in a liquid bridge of silicon-oil-based ferrofluid under zero gravity. The mass conservation level set method is used to capture the motion of the free surface. The obvious effects of the transverse magnetic field on the flow and temperature distributions as well as surface deformation are detected. The transverse magnetic field affects not only the velocity level inside the liquid bridge but also the velocity level on the free surface. Moreover, the present results prove that it is necessary to take the surface deformation into account in the study on the thermocapillary convection.
Experimental study on dynamic nonlinear electromechanical behaviour of the macro fiber composite
Authors: Chen Luqi , Zhang Ping , Yu Kui , Sun Qing
Published: December 2018

The primary objectives of this work are about the experimental study on the nonlinear electromechanical behaviour of the macro fiber composite(MFC), and to analyse the affecting factors of the inconstant parameters d33 and d31 which can arouse nonlinearities of MFC. Both longitudinal and transverse output strains are measured by actuating the MFC specimen under different DC voltages and a range of peak-to-peak sinusoidal voltages (VPP) at various frequencies, which can investigate how the voltage amplitude and frequency affect nonlinear hysteretic behavior. The experimental results of both DC voltages and AC voltages indicate that the relationship of the applied voltage and output strain displays nonlinear hysteretic behavior. The responses of the AC voltages also indicate that hysteresis nonlinearity behaviour of the MFC actuator is sensitive to the varying voltage amplitude and frequency. The higher the voltage and frequency are, the more obvious the hysteresis phenomenon are.
Investigation on the performance of a small sized PM type stepping motor with a newly structured claw-poles
Authors: Rhyu Se-Hyun
Published: December 2018

This paper presents the dynamic characteristic analysis of a small sized permanentmagnet (PM) type stepping motor with newly structured claw-poles. First, the motor parameter is derived by PM analyzing torque and back-EMF using the 3-D finite element analysis (FEA) taking account magnetization of PM. Next, the dynamic characteristic of a small sized motor is calculated by magnetic circuit equation coupled with 3-D FEA. Specially, we propose a test method of step response for a small sized PM type stepping motor using a position sensitive detection (PSD) sensor. From the simulation and test results, it is shown that the proposed dynamic characteristic analysis method has usability for a very small sized motors.
Study on flexible piezoelectric device for compressive loads
Authors: Shinagawa Kazuki , Tanaka Yoshikazu , Mutsuda Hidemi
Published: December 2018

A flexible piezoelectric device is proposed that can generate power from vibrations produced by vehicles or plants. The results of an experiment on a small and flexible piezoelectric power generator are presented herein. Forced vibration experiments were performed, and the results for the relationship between output power and vibration characteristics are discussed.
Comparison of slot and slotless type stator cores of a super high speed motor-generator for microturbine generators
Authors: Hong Do-Kwan , Joo Daesuk , Woo Byung-Chul , Koo Dae-Hyun
Published: December 2018

The aim of the present study is to develop a motor-generator that fits into a microturbine generator (MTG) system with a power density of 500 W class considering the DC load. The performance evaluation of the motor-generator is performed by back-to-back tests according to AC and DC load to evaluate the power generating characteristics. The power generating characteristics simulation is compared with the experimental results. The analysis results are in accord with the experiment results considering AC and DC loads. The slot model is determined by several characteristics, such as size constraint and the mechanical and electrical performance results between slot and slotless models.
Inductive and solid-state sensing of pulsed eddy current: A comparative study
Authors: Mandache Catalin
Published: December 2018

In recent years, solid-state devices made their way in the development of electromagnetic non-destructive evaluation (NDE) probes. This fact was evidenced especially for pulsed eddy current, where magneto-resistive and Hall effect devices are used as sensing elements. Their low frequency range and small surface area are suitable to improve the detection of buried and small discontinuities. Although their properties are expected to enhance detectability over simple induction coils, this was still to be proven or demonstrated in a comparative study. This work compares the sensing capabilities of an induction coil to those of two solid-state devices: giant-magneto-resistive (GMR) and Hall effect sensors. All of them are used as detectors in pulsed eddy current probes that have the same excitation mechanism, a ring-type copper coil driven by a constant amplitude square waveform. While the excitation part of the probe is fixed, the sensing components are inter-changeable. Although both induction coils and solid-state sensors output a voltage value as an indication of the magnetic field they are detecting, the voltage for pick-up coils is directly proportional to the rate of change of the magnetic flux. For solid-state sensors the output is in direct relation to the detected magnetic field. Under this study, all three sensing elements are used to detect the driving coil's magnetic output (magnetic field or flux) in air, on planes perpendicular and parallel to the face of the driver coil. The results obtained by all three sensors are quantitatively compared. Then the sensing devices are inserted in the inner space of the driving coil and, subsequently, used for detection of artificially made defects. Finally, the results are compared in terms of magnetic field sensitivity and inspection performance.
Analysis of IPMSM characteristics considering the temperature change
Authors: Kim Bo-Mi , Choi Myoung-Hyun , Park Kwan-Tae , Kim Byung-Taek
Published: December 2018

In this paper, the analysis method is proposed to analyse the performance of the interior permanent magnet synchronous motor (IPMSM) considering the thermal characteristic. An accurate motor characteristic analysis is conducted by presenting the changes in circuit parameter due to the temperature rise and connecting them to thermal equivalent circuits. The arbitrary motor is selected to compare the test results and analysis results to validate the proposed characteristic analysis method.
Design of an on-line observer of LIM servo systems using transient FEM and experimentation for sensorless vector control
Authors: Lee Jung Ho , Kim Young Hyun
Published: December 2018

This study deals with the dynamic characteristic analysis of a Linear Induction Motor (LIM), using a finite element method in which a moving mesh technique is considered. The focus of this paper is to show the suitability of an on-line observer system for position sensorless control of a LIM under phase asymmetry, saturation and iron loss.

Comparisons are given both from the angle of the observer and that of the proposed FEA method of a linear induction motor. The position control system is realized, and the effectiveness of the observer system for the flux angle is verified by experimental results.
Numerical simulation of magnetic incremental permeability for ferromagnetic material
Authors: Chen Hong-En , Xie Shejuan , Zhou Haiqiang , Chen Zhenmao , Uchimoto Tetsuya , Takagi Toshiyuki , Kensuke Yoshihara
Published: December 2018

Magnetic Incremental Permeability (MIP) method practiced as a NDT technique to evaluate the material degradation is based on the eddy current testing in addition to a low frequency bias magnetic field generated by an electromagnetic magnet. To clarify the mechanism of MIP and to find optimal probe design, a numerical method to simulate MIP profile is important. In this paper, a simulation scheme and a numerical code are developed for MIP of ferromagnetic material based on the simulated polarization strategy and the reduced vector potential formulae. Experiments are also conducted for test-pieces of carbon steel to demonstrate the validity of the proposed scheme.
Viscous and damping properties of magnetic compound fluids containing alpha-cellulose
Authors: Ido Yasushi , Hayashi Koichi , Ueno Satoshi , Todaka Takashi
Published: December 2018

Viscous, magnetization and damping properties of magnetic compound fluids containing fibrous material such as alpha-cellulose were investigated experimentally. It is shown that adding fibrous material to magnetic functional fluids is effective on increasing viscosity on the fluid while the amplification ratio of damping force in the presence of magnetic field against damping force in the absence of magnetic field decrease with increase of volume fraction of the fibrous material.
Numerical research on electro-elastic properties of the macro fiber composite (MFC) actuators
Authors: Zhao Jianhua , Man Xingbo , Xue Xiaomin , Sun Qing , Zhang Ling
Published: December 2018

The recently developed macro fiber composite (MFC) actuators are widely used in a variety application due to their high performance, flexibility and durability when compared with the prior actuators. This paper aims to model and compute the effective electromechanical properties of MFC actuators using the finite element method (FEM) and verify the accuracy the model through the experimental test. The results indicate that the FEM results are in good agreement with the experimental data. It demonstrates that the finite element(FE) model is effective to predict the electro-elastic properties of MFC when the electric field is applied.
Fault detection and diagnosis in a set "inverter-switched reluctance motor" based on pattern recognition using Kalman filter prediction
Authors: Bouchareb Ilhem , Bentounsi Amar , Lebaroud Abdesselam
Published: December 2018

In the case of one phase failure, the switched reluctance motor(SRM) will behave nearly the same, both in open circuit and in short circuit failure. This means, that the machine will understand the two faults in the same way which makes the SRM faults detection and diagnosis a more challenging task. This paper presents a diagnosis method based on pattern recognition analysis to detect and to classify automatically the electrical faults, short- and open-circuit under any level of load of the studied system: redundant three-phase power converter fed 6/4 SRM. The phases making a pattern recognition diagnosis of SRM, the training and the decision. The training phase consists in determining the pattern vector and the optimal kernels design (the separating classes) by Time-Frequency Representation (TFR). The training data is carried out using a set of fault scenarios, between healthy, single and combined faults, in terms of torque measurement at different load level, in order to deduce the fault severity. The second phase, consists in associating an unknown pattern with one of the defined classes, according to the "k-nearest neighbors" (knn) decision rule, associated with Kalman estimator to tracking of various operating modes and to predict the evolution of the call out of the knowledge database for a given operating mode in order to realize a preventive maintenance. The experimental results prove the efficiency of pattern recognition methods in condition monitoring of reluctance machine.
Terahertz examination of fatigue loaded composite materials
Authors: Lopato Przemyslaw , Chady Tomasz
Published: December 2018

The aim of this study was to investigate the possibility of using electromagnetic radiation in the terahertz frequency range for testing of polymer composites. Glass, natural and basalt fiber reinforced polyester composites as well as sandwich structures after fatigue tests were evaluated. We examined detection abilities of detects and inhomogeneities occurred during bending process at various amounts of load cycles. Extraction and monitoring of proposed parameter enables accurate evaluation of composite structures condition.
Evaluation of plastic deformation and characterization of electromagnetic properties using pulsed eddy current testing method
Authors: Xie Shejuan , Chen Zhenmao , Chen Hong-En , Sato Seiya , Uchimoto Tetsuya , Takagi Toshiyuki , Yoshida Yasuhiko
Published: December 2018

Plastic deformation, as a type of micro-damage caused by external loads such as earthquake, is necessary to be evaluated by using an efficient non-destructive evaluation technique in order to guarantee the structural safety. In this paper, the feasibility of the pulsed eddy current testing method for evaluating the plastic deformation in an austenitic stainless steel has been studied through experiments and simulations. Moreover, the electromagnetic property variations due to plastic deformation have also been investigated.
Development of a pulsed power system using MOSFETs and underwater pulsed electric discharge
Authors: Sato Morihiko , Oya Ryusuke , Ishikawa Takeo
Published: December 2018

We have developed a high-frequency pulsed power generation system using either ten or twenty MOSFETs in series. The operation principle of the circuit was elucidated, and the experimental results confirmed the operation of the developed circuit. When twenty MOSFETs were used, repetitive operation was achieved at an output voltage of 10 kV and a frequency of 1 kHz. A preliminary experiment on underwater pulsed electrical discharge is performed, and the occurrence of underwater pulsed electric discharge was confirmed.
Numerical representation of two-dimensional magnetostriction in electrical machines
Authors: Wakabayashi Daisuke , Enokizono Masato
Published: December 2018

In order to reduce acoustic noises and vibrations of electrical machines caused by magnetostriction, it is necessary to make clear the distribution of magnetostriction on magnetic core. The distribution of magnetostriction has been visualized by measured two-dimensional magnetostriction of electrical steel sheet and vector magnetic characteristics analysis technique. The distributions of vector magnetic characteristics and magnetostriction and the relationship between the magnetic flux density vector and two-dimensional magnetostriction have been made clear in the method.
A hybrid finite element model for spiral coil electromagnetic acoustic transducer (EMAT)
Authors: Dhayalan R. , Kumar Anish , Rao B. Purna Chandra , Jayakumar T.
Published: December 2018

This paper discusses finite element modeling of spiral coil electromagnetic acoustic transducer (EMAT) to generate bulk waves. First, a 2D electromagnetic model is developed for calculating the Lorentz force density, which is the driving force for sound wave generation within the material. Second, the calculated force at each point in the material is used as the driving force for generating sound wave modes. This model is used to predict the ultrasonic A-scan signals of bulk (longitudinal and shear) waves in isotropic homogeneous material. Spiral coil EMATs of two different coil spacings are developed for experimental studies. The model predicted results are validated by experimental results and for this, the ratio of amplitude of shear wave to longitudinal wave is used.
Unusual microwave effective properties of two-component metaferrites
Authors: Rybin Oleg
Published: December 2018

The paper discusses microwave properties of the effective refractive index of two-component metamaterials with ferromagnetic metal inclusions. Here we study metamaterial media, which are presented as an infinite host dielectric material with periodically embedded ferrite-like metal cylindrical and spherical inclusions saturated with an external biasing magnetic dc field. The case when electromagnetic wave propagates transversely or parallel to the direction of biasing magnetic dc field is studied. Frequency ranges where the real parts of effective refractive index of the metamaterials achieve unusual values (very small, much greater than unity etc.) were found.
A numerical study on the performances of the flexible BiCGStab to solve the discretized E-field integral equation
Authors: Angiulli G. , Cacciola M. , Calcagno S. , De Carlo D. , Morabito C.F. , Sgró A. , Versaci M.
Published: December 2018

To efficiently solve the large, dense and non-Hermitian matrix system provided by the E-field Integral Equation (EFIE) modelization of the electromagnetic scattering by arbitrarily shaped perfect conducting bodies, the Generalized Minimal Residual method (GMRES) with preconditioning is usually employed. Nonetheless, even if optimal in a broad sense, the GMRES suffers of the drawback that its memory space demand grows linearly with the number of iterations. To avoid possible out-of-memory errors, a Krylov subspace method involving a fixed amount of memory per iteration has to be used. This is the case of the Bi-Conjugate Stabilized (BiCGStab) method. Although this method has been exploited with success to handle dense matrix system arising from EFIE discretization, its flexible version, the Flexible-BiCGstab, at the best of the authors knowledge, has not received any attention within this context. In this work, a study on the performances of the Flexible BiCGStab to solve the discretized EFIE is presented. Numerical results demonstrate that the Flexible BiCGStab is, at least in the examined cases, a workable alternative to the the standard BiCGStab with ILUT preconditioning.
Textile vee antena made with PVD process
Authors: Januszkiewicz Łukasz , Hausman Sławomir , Nowak Iwona , Krucińska Izabella
Published: December 2018

In the paper a textile Vee antenna made through physical vapor deposition of metal on textile material is presented. It can accomplish a wider frequency bandwidth than that of the original Vee antenna made with the embroidering technique. Dependence of both impedance and radiation patterns of the antenna on various values of the technology parameters is investigated. The radiation pattern is examined both for free space and on-body locations.
Studying flow and heat transfer characteristics of magnetic nanofluid under the effect of magnetic field using Euler- Lagrange approach
Authors: Bahiraei Mehdi , Hangi Morteza
Published: December 2018

This study has used the two-phase Euler-Lagrange method to evaluate the hydrothermal characteristics for a laminar flow of water-Mn _{0.6} Zn _{0.4}Fe_{2} O _{4} magnetic nanofluid in a circular pipe under the effect of magnetic field with both positive and negative gradients. Brownian and thermophoretic forces were considered in the simulation. Concentration distribution was found to be non-uniform at the cross section of the pipe, the value of which is greater in center of the pipe than near wall. Non-uniformity in the concentration distribution will change the velocity profile under the application of magnetic field. Applying magnetic field with negative gradient increases the convective heat transfer coefficient, while decreases it in the case of positive gradient. Increasing the magnitude of magnetic field gradient causes a more considerable change in the convective heat transfer coefficient. In the presence of the magnetic field, the convective heat transfer coefficient also increases with increasing Reynolds number, concentration and particle size which the effects of magnetic field on heat transfer is less significant at higher Reynolds numbers. Moreover, the pressure drop increases in the case of applying magnetic field with negative gradient while applying the positive one would act as a pump and sucks the fluid from upstream.
Two-stage method of Barkhausen noise measurement
Authors: Pal'a Jozef , Bydžovský Jan
Published: December 2018

A simple method of measuring the Barkhausen noise in two stages was developed. The purpose of the proposed method was to remove the magnetizing frequency component from the induced electromotive force signal without using complex analog or digital filters, which also suppress the Barkhausen noise. In the first stage, an instance of the electromotive force signal was temporarily recorded, and in the second stage another instance of the electromotive force signal subtracted from the previously recorded instance of the electromotive force signal was measured. Using this method we will obtain only the stochastic component of the electromotive force signal – the Barkhausen noise. The method is illustrated on measuring the Barkhausen noise in an electrical steel sample. The experiments proved that with this method we are able to remove the dominant continuous component from the induced electromotive force signal and we can simplify the measurement. The general problems associated with the method are discussed.
Reviews on simulation methods for the microstructure of magnetic fluid with and without applied magnetic field
Authors: Zhao Yong , Li Hao , Lv Ri-Qing , Hu Hai-Feng
Published: December 2018

Magnetic fluid was a novel functional material with many unique properties, especially in the case that the magnetic field was applied. It was found that the special properties of magnetic fluid were determined by its unique microstructure. Then, the special properties could be understood fundamentally by researching the extraordinary nature of the microstructure of the magnetic fluid. At the same time, it was a good theoretic guidance for the experimental research on the properties of magnetic fluid to make clear about the microstructure model theoretically. Therefore, it was particularly important to study the simulation methods to obtain the microstructure of magnetic fluid. The development of the microstructure simulation methods of magnetic fluid were introduced in this article, and the basic principles of various simulation methods were expounded in detail. The features of each microstructure simulation methods of magnetic fluid were summarized and compared with each other. Finally, the key problems and research direction of the numerical simulation method in the future were described.
Intern-turn short-circuit fault detection in switched reluctance motor utilizing MCPT test
Authors: Torkaman Hossein
Published: December 2018

The performance of the Switched Reluctance Motors (SRMs) in different applications has widely been investigated by various studies. The research areas are oriented toward fault effects on electromagnetics behavior and its diagnosis for operation improvement. One of the most observed faults is the stator winding short circuit which may lead to produce the unbalanced distribution of magnetic field. In this paper, it is attempted to firstly introduce the conventional SRM and new structure of double stator SRM (DSSRM). Secondly, by means of three dimensional finite element method (3D FEM) the effects of short-circuit faults (SCF) on motor profiles are investigated, in which static and dynamic behaviors of the motor in healthy and several SCF conditions are evaluated. A new method namely as maximum current point tracking(MCPT) is introduced to evaluate the SCF in SRM, so an index is proposed to detect the numbers of shorted turns in faulty phase. The overall outcomes highlight the advantages of using this method and index which is general enough to be applied to any type of SRM.
Uncoupled thermomagnetoelastostatics for long cylinders carrying a steady axial electric current by a boundary integral method. A numerical approach
Authors: El Dhaba A.R. , Ghaleb A.F. , El-Seadawy J. , Abou-Dina M.S.
Published: December 2018

The static, uncoupled problem of thermomagnetoelasticity for long cylinders carrying a steady, axial current is investigated in stresses within a numerical approach by a boundary integral method in terms of real harmonic functions.This is the numerical realization of the field equations, boundary conditions and other relations presented in [1]. The method is complemented by the use of boundary collocation method to evaluate some path-independent line integrals needed in the representation of the mechanical displacement field. The material of the cylinder is assumed homogeneous and isotropic, and linear dependence of the magnetic permeability on strain is taken in consideration through two material constants. Formulae are obtained for the boundary values of functions of practical interest like stress and mechanical displacement. Evaluation in the bulk may then be carried out by quadrature on the basis of well-known formulae of the theory of potential. The special case of an elliptic boundary is treated and the results are compared to the analytical solution established in [11]. It is concluded that the proposed numerical scheme performs efficiently in this case, and may thus be used for other forms of the boundary, subject only to smoothness condition.
Automated sampling point refinement procedure for 2-D high saturated magnetic field analysis by surface current method
Authors: Arehpanahi Mehdi , Jamal Naser Saberi
Published: December 2018

In this paper, a new sampling point refinement for saturation modeling in Surface Current Method (SCM) is proposed. In this method the variable permeability inside the magnetic materials due to the saturation is defined by optimization of sampling point number and their positions. In other words, the sampling points inside the material are refined for any current value and air gap variation. These results depend on magnetic energy of sampling points inside the material and the value of them is strongly depend on sampling point positions. Simulation results verification have been done with the FEM.
Modified BNMR algorithm applied to Loney's solenoid benchmark problem
Authors: Taherdangkoo Mohammad , Taherdangkoo Reza
Published: December 2018

We propose a new method for solving the Loney's solenoid benchmark problem based on Blind, Naked Mole-Rats (BNMR) algorithm. The key idea of the algorithm is using a \beta -distribution that can efficiently achieve the best solution for the position and size of two correcting coils in the famous Loney's solenoid problem. The results show the superiority of the proposed method on other previously methods for electromagnetic optimization.
Dynamics for an electromechanical integrated harmonic piezodrive system
Authors: Xu Lizhong , Li Huaiyong
Published: December 2018

The Authors propose an electromechanical integrated harmonic piezodrive system. The dynamics behavior of the movable tooth drive has important effects on its operating performance. Here, the dynamic equations of the movable tooth drive for the drive system are presented. Using the equations, the natural frequencies and vibrating modes of the movable tooth drive are investigated. Results show that five vibrating modes occur for the movable tooth drive which include system modes, static crown gear modes, movable tooth modes, translating rotor modes and translating crown gear modes. Eccentric center, thickness and length of the flexible ring, diameter of the movable tooth and speed ratio have significant effects on the natural frequencies of the movable tooth drive and should be selected properly.
PM2.5 removal performance of a wire-pipe ESP under multi-field coupling and applied magnetic field
Authors: Zhang Jian-Ping , Fang Fang , Pan Wei-Guo , Wu Helen , Ren Jian-Xing
Published: December 2018

In order to study PM2.5 removal performance under multi-field coupling and applied magnetic field, a mathematical model was proposed to analyze the interaction between fluid flow field, electro- magnetic field and particle dynamic field. The computational fluid dynamics method and FLUENT were employed to numerically simulate the PM2.5 removal performance in a Wire-pipe ESP. The effects of magnetic field on PM2.5 collection efficiency at different working voltages and gas velocities were discussed. The results indicate that the influence of applied magnetic field on PM2.5 collection in the wire-pipe ESP becomes more obvious with the increase of the particle diameter, and the increment of PM2.5 grade efficiency decreases with the increasing magnetic flux density in a certain range of particle diameters. Furthermore, the effect of magnetic field on PM2.5 collection increases with a decrease of working voltage or an increase of gas velocity, and PM2.5 collection efficiency declines at the same time. At a lower flue gas velocity, the impact of flue gas velocity on PM2.5 overall efficiency is more significant than that of applied magnetic field.
Hybrid controller design of a free-piston energy converter
Authors: Pang Yan , Xia Hao
Published: December 2018

A Free Piston Energy Converter (FPEC) is a combination of a linear combustion engine and a linear electrical machine. It is a potential technology for series hybrid vehicles, as well as stationary power generation applications. In a free piston energy converter, the piston is not connected to a crank-shaft. Instead, the piston movement is "free" and controlled by a linear hydraulic or electric machine. The major advantages of such a design over the conventional ones are the simpler engine layout and much improved conversion efficiency. Unlike other traditional modeling method, in this paper, the free piston converter is modeled as a hybrid automaton. A hierarchical hybrid controller is designed based on this model. The hybrid controller includes a discrete controller which is in charge of switching actions and a continuous controller which compute the electro-magnetic force. High-fidelity simulation results are provided to illustrate the applicability and performance of developed control law.
Stroke and natural frequency estimation for linear compressor using phasor algorithm
Authors: Tang Mingsheng , Zou Huiming , Xu Hongbo , Shao Shuangquan , Tian Changqing
Published: December 2018

The stroke and natural frequency are key controlling quantities for linear compressor controller. This paper proposes a phasor algorithm for the linear compress stroke and natural frequency calculation. The phasor algorithm employs vectors to express the voltage, current and velocity respectively for the calculation in frequency domain. A test bench has been installed, and the feasibility of phasor algorithm is verified with the linear compressor load changing. The relative deviation of the calculated stroke can be achieved within ± 3% experimental results at 0.4 MPa, 0.5 MPa and 0.6 MPa discharge pressure respectively. The calculated results shows that the computation time of phasor algorithm is one-third shorter than that of time domain algorithm, which means it is possible to employ relatively low energy consumption and low cost hard ware. The calculation natural frequency decreases with the stroke increases at 0.4 MPa, 0.5 MPa and 0.6 MPa discharge pressure respectively, and the tested motor efficiency reaches a maximum when the calculated natural frequency equals to the operating frequency.
Parallel principal components algorithm for OMA following Sanger neural network
Authors: Wang Cheng , Huang Haiyang , Zhang Tianshu , Chen Yewang , Zhang Yiwen , Cheng Jianwei
Published: December 2018

To address the problems of singularities, sensitivity to measurement noise, and low efficiency in traditional principal component analysis (PCA)-based operational modal analysis (OMA), we present a Sanger neural network principal component analysis (SNNPCA) algorithm to identify the operational modal parameters. SNNPCA is a two-layer neural network that is trained using a generalized Hebbian algorithm to ensure that its output converges to the principal components. After SNNPCA has converged, the link weights of SNNPCA correspond to the separation matrix of PCA. In SNNPCA-based OMA, the measurement response points are set as the input neurons, modal coordinate response signals are set as the output neurons, and the link weights of the neural network represent the modal shapes. Therefore, the operational modal identification process in SNNPCA is physically meaningful and convergent. Furthermore, SNNPCA inherits the parallel nature of neural network algorithms, so it is also insensitive to measurement noise. Simulation results show that SNNPCA can identify the principal modal parameters accurately using only measurement response signals. This method can be applied in embedded devices to realize online monitoring and real-time fault diagnosis.
Electromagnetic inspection method of carburization depth inside and outside of heating furnace steel tube
Authors: Yoshioka Saijiro , Marumoto Tatsuya , Gotoh Yuji
Published: December 2018

The crude oil which flows inside the steel tube of a heating furnace of an oil-refining plant is gasified by being heated with the burner from the surface outside the steel tube. Since this steel tube is used in Japan for 30 years or more, both the inner side and outer side of the steel tube is carburized. If the carburization depth is increased, the steel tube will be exploded suddenly and a big accident may occur. In this paper, the electromagnetic inspection method for measuring the carburized depth of both the inner side and the outer side of the steel tube is proposed. The both depth is obtained by evaluating the flux density in layers with and without carburization in the steel tube using the 3-D nonlinear FEM. It is shown that the inspection for the both depth is possible by using the differential electromagnetic characteristics of the layers with and without carburization in the steel tube.