International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Kumaran, Nithila | Arunachalam, Kavitha

Article Type: Research Article

Abstract: An electrically thin (0.024𝜆0 ) high-impedance surface (HIS) on a magneto-dielectric nanocomposite (NC) is presented as an external shield for wideband absorption of mobile phone radiation. Characterization of the NC and numerical design and analysis of the miniaturized HIS unit cell on NC (0.088𝜆0  × 0.088𝜆0 ) are presented over 0.85–6 GHz, where 𝜆0 is the free space wavelength at the absorber resonant frequency. The absorber performance is assessed using a mobile phone handset at 0.9 and 1.8 GHz Global System for Mobile Communications (GSM) frequencies and 2.4 GHz Wireless Fidelity (WiFi) frequency. Handset specific absorption rate (SAR) measurements with the absorber recorded …in head phantom indicated 83, 48 and 71% reduction in peak SAR at 0.9, 1.8 and 2.4 GHz, respectively without significantly affecting the handset radiation characteristics in free space. Simulation results of human head model with the hand showed SAR reduction of 69, 24 and 65% at 0.9, 1.8 and 2.4 GHz, respectively for 1 g SAR. It is concluded that the proposed absorber could be used to lower handset SAR levels and shield mobile communication signals over 0.85–6 GHz. Show more

Keywords: EM shielding, high impedance surface, mobile phone, nanocomposite, SAR

DOI: 10.3233/JAE-210092

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2021

Authors: Chen, Jun-Wei

Article Type: Research Article

Abstract: For precision engineering, a linear PM-moving actuator with trapezoidal PMs and trapezoidal coils considering the fringing effect is proposed. To take into account the effect of the finite-long trapezoidal PM array, an improved Fourier series expansion is developed to calculate the fringing-included magnetic field. Then the full-stroke thrust excited by the trapezoidal coils is accurately predicted and validated by the finite element method. Sensitivity of the trapezoidal parameters of PMs and coils is analyzed, and combined optimization is implemented by the genetic algorithm. Through the Pareto optimal solutions of thrust, the relation of the PM-coil parameter combination is described and …formulated by curve fitting. Compared with the traditional rectangular PM actuators or other trapezoidal-typed actuators, the proposed actuator with trapezoidal PMs and coils further decreases the thrust ripple and largely increases the thrust magnitude simultaneously, and reaches an utmost-close effective stroke as well. Show more

Keywords: Trapezoidal PMs, trapezoidal coils, linear PM actuator, fringing effect, Fourier series expansion, combined optimization

DOI: 10.3233/JAE-210050

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2021

Authors: El-Dabe, Nabil T.M. | Abou-Zeid, Mohamed Y. | Oauf, Mahmoud E. | Mostapha, Doaa R. | Mohamed, Yasmeen M.

Article Type: Research Article

Abstract: The present investigation analyzes the influence of Cattaneo–Christov heat and mass fluxes on peristaltic transport of an incompressible flow. The fluid is obeying Bingham alumina nanofluid. The fluid flows between two co-axial vertical tubes. The system is expressed by a varying radially magnetic field with respect to the space. Soret effect and non-Darcy porous medium are taken into account. The governing system of equations is tackled by utilizing the approximations of long wavelength with low Reynolds number and with the help of homotopy perturbation method (HPM). It is noticed that the axial velocity magnifies with an increase in the value …of Bingham parameter. Meanwhile, the value of the axial velocity reduces with the elevation in the value of the magnetic field parameter. On the other hand, the elevation in the value of thermal relaxation time leads to a reduction in the value of fluid temperature. Furthermore, increasing in the value of mass relaxation time parameter makes an enhancement in the value of nanoparticles concentration. It is noticed also that the size of the trapped bolus enhances with the increment in the value of Bingham parameter. The current study has many accomplishments in several scientific areas like medical industry, medicine, and others. Therefore, it represents the depiction of the gastric juice motion in the small intestine when an endoscope is inserted through it. Show more

Keywords: MHD, peristaltic flow, Bingham model, alumina nanofluid, Cattaneo–Christov heat flux, non-Darcy porous medium

DOI: 10.3233/JAE-210057

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-26, 2021

Authors: Guesmi, Mohamed | Harzallah, Salaheddine | Kouzou, Abdellah

Article Type: Research Article

Abstract: Crack orientation is a vital factor in the behavioral study of fractures, especially the study of crack propagation in structures that are under dynamic or fatigue loading. Indeed, many non-destructive testing (NDT) techniques have been developed recently for the detection of cracks such as the eddy current testing (ECT). However, the crack orientation has not been undertaken into consideration. In this paper, a NDT based on eddy current using 3D finite element modeling, is proposed for the determination of the crack orientation. The idea of this proposed technique benefits from the influences of crack orientation, which can be observed on …the components of eddy current and the related magnetic flux density following the x , y axes, for the estimation of the crack angle orientation based on an interpolation criteria. The obtained results through the presented simulation prove the validity of the proposed technique for the detection of crack angle orientation. Show more

Keywords: Crack orientation, eddy current, non-destructive testing, finite element modeling, stress intensity factor, J-integral

DOI: 10.3233/JAE-210049

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2021

Authors: Qing, Li | Miao, Tian | Peng, Gao | Jie, Teng | Bing, Wang | Qing, Tang Bruce | Hong, Wu

Article Type: Research Article

Abstract: Many kinds of physical field are able to affect the biological activity, such as electromagnetic field, magnetic field, scalar wave, magnetic vector potential and so on. Some works investigated a high-penetrating emission (HPE) generated by a LED generator that can affect the conductivity of water and the growth of dry yeast. In this research, the biological effect of the HPE of LED generator on S. cerevisiae was studied. The results showed that this kind of HPE could promote the growth of S. cerevisiae . With the decrease of initial concentration and the extension of exposure time, the growth promoting …effect of HPE increased significantly. When the initial cell concentration was 2 × 102  cell/ml and exposed for 24 h, the number of yeast cells increased by 19.5% compared with the control group. Further studies showed that adenosine triphosphate (ATP) content and the ratio of ATP and adenosine diphosphate (ADP, ATP/ADP ratio) of exposed cells were higher than those of unexposed cells, indicating that exposed cells had higher cell viability and energy status. In addition, the intracellular superoxide (O2 − ) content decreased significantly after the HPE exposed. In this study, the stainless steel box acts as a Faraday cage to shield the electromagnetic field, so the biological effect of the HPE is not produced by the electromagnetic field. Nevertheless, the mechanism of the HPE is still unknown and needs further research. This is the first report on the effect of HPE on mitochondrial parameters, contributing to further study on HPE and revealing potential for future medical applications. Show more

Keywords: HPE, Saccharomyces cerevisiae , growth, superoxide, ATP/ADP ratio

DOI: 10.3233/JAE-210054

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-8, 2021

Authors: Akdoğan, Hilmi | Tabatadze, Vasil | Karaçuha, Kamil | Yaldiz, Ercan

Article Type: Research Article

Abstract: The study investigates basically, the electric field distribution in a semi-closed region. Specifically, the present work focuses on the electromagnetic wave diffraction at 3.5 GHz in the vicinity of a car where two humans are located inside. The car is modeled as the perfect electric conducting object whereas the human bodies are assumed to be homogeneous lossy dielectrics. To obtain field distributions for different sceneries, the Method of Auxiliary Sources (MAS) is employed. To achieve this goal, the auxiliary sources due to each obstacle are distributed over the corresponding surface element. In the present study, two main different scenarios are considered. …One or two cellphones as the source of electromagnetic waves are considered. These cellphones are operating at the proposed 5G frequency band in the European Zone. In this frequency range, the resonances are observed at 3.5 GHz which is in the range of a planned 5G communication frequency band. The present study aims to obtain quantitative and qualitative results for a better understanding of 5G healthy issues. Therefore, as a frontier study, the specific absorption rate (SAR) values are examined for the first time to answer some important questions related to 5G. For such a scenario, MAS is a very efficient, fast, and trustworthy approach to obtain field distribution at semi-closed regions. Show more

Keywords: Car, computation electromagnetics, electromagnetic diffraction, human body, MAS

DOI: 10.3233/JAE-210035

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021

Authors: Hu, Yongpan | Long, Zhiqiang | Xu, Yunsong | Wang, Zhiqiang

Article Type: Research Article

Abstract: Poor stability of the permanent magnet electrodynamic levitation hinders its application in the maglev field. Therefore, building a control-oriented model to improve its stability is most challenging. However, intractable electromagnetic models leading to an implicit relationship between levitation force and gap, yields a barrier for model-based controller design. To solve the above-mentioned problem, this paper develops a control-oriented model by two stages. Specifically, the first stage is to show an explicit formula of the levitation force with regard to the levitation gap by neglecting end effect; meanwhile the “maximum–minimum rectification” method is put forward to evaluating an accurate levitation force. …The second stage is to bring forth the control-oriented model on basis of the estimated levitation force. Although the paper focus mainly on the development of the control-oriented model, an example of PD controller is provided to verify its validation. Experiment results demonstrate the estimated levitation force is highly consistent with the real one. Simulation results show that the control-oriented model is sufficiently reliable. The research bridges the gap between the physical model and the model-based controller for the electrodynamic levitation with permanent magnet Halbach array. Show more

Keywords: Electrodynamic levitation, Halbach array, control-oriented, levitation force

DOI: 10.3233/JAE-210007

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-19, 2021

Authors: Xia, Yunyan | Du, Hao | Shao, Yuanliang

Article Type: Research Article

Abstract: This paper aims to propose a method to determine the temperature rise and rated capacity of induction motors under different working systems. A dynamic mathematical model, a 3D temperature field model, and finite element method are used to analyze the electromagnetic loss and transient temperature rise, respectively. The influence of the motor starting process on the temperature rise is taken into account, which resolves the complex loading of transient heat source. The maximum allowable running times for the motor operating with different overloads are determined. The relationship between the motor output power and the allowable running time is obtained, and …it provides a basis to determine the rated capacity of motor under S2 working system. The relationship between the motor output power and the temperature rise under different load duration rates is also obtained and provides reasonable evidence to determine the rated capacity of the motor under S3-working system. Show more

Keywords: Induction motor, finite element method, transient temperature, rated capacity

DOI: 10.3233/JAE-210004

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2021

Authors: Lakshmi, C.R. | Kannadassan, Dhanaraj

Article Type: Research Article

Abstract: This paper reports the demonstration of design and implementation of narrow band band-stop filters using slotted ground resonators. Using coupled-mode resonator theory, the systematic implementation of BSFs are performed to achieve narrow stopband (<25% FBW) with desired stopband isolation. By exchanging the band-pass transfer function polynomials, the BSF design has become straight-forward with these band-stop resonators. Designed and optimized BSFs are fabricated, characterized and analysed as a detailed report. Slotted ground resonators yield compact and scalable BSFs which are potential alternatives for the development of future microwave systems.

Keywords: Slotted ground resonators (SGR), band stop filters (BSF), fractional bandwidth (FBW), coupled resonators

DOI: 10.3233/JAE-210019

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021

Authors: Park, Sohyun | Lee, Jaejoon | Lee, Jaewook

Article Type: Research Article

Abstract: This paper presents a multi-material topology optimization for the design of permanent magnet synchronous motors (PMSMs). Specifically, structural shapes of permanent magnet (PM) and iron core in a PMSM rotor are simultaneously designed together with the orientation of PM magnetization. For a co-design of PM and iron core, relative permeability and residual magnetic flux density are interpolated by the three-field density approach based on the Helmholtz filtering and regularized Heaviside step function. Here, the Helmholtz filtering aims to attain smooth border in design results, and the Heaviside function enables us to acquire a clear border (i.e. zero-one design) without intermediate …densities. The optimization goal is set as maximizing the average torque of PMSMs. The average torque is calculated by Maxwell stress tensor (MST) method considering a maximum torque per ampere (MTPA) control. To validate the effectiveness of the proposed multi-material topology optimization approach, a PMSM rotor with 4 poles and 12 slots is designed. In addition, design results at various settings of input current amplitude and PM strength are compared and discussed. When the input current is stronger than the PM strength, rotor PM and iron core are designed for utilizing both PM and reluctance torque components like V-shape interior PMSMs. On the other hand, in the case of stronger PM strength, PM is designed near the air-gap, which utilizes only PM torque component like surface PMSMs. Show more

Keywords: Topology optimization, permanent magnet synchronous motors (PMSMs), permanent magnets (PMs), iron, finite element methods

DOI: 10.3233/JAE-210062

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2021

Authors: Hu, Guoliang | Qi, Haonan | Chen, Miao | Yu, Lifan | Li, Gang | Zheng, Han

Article Type: Research Article

Abstract: In this paper, a magnetorheological (MR) damper with multiple axial fluid flow channels is developed to solve the conflicts between limitation of size dimension and improvement of damping performance. By setting symmetrical excitation coils at both ends of the MR damper, the effective fluid flow channels of the proposed MR damper are significantly lengthened. In order to investigate the distributions of magnetic flux lines and magnetic flux density of the MR damper, the finite element model of the MR damper is established by using ANSYS software. Moreover, an optimization method combining BP neural network and particle swarm optimization (PSO) is …proposed to improve the magnetic field utilization of the designed damper, and the damping performances of initial and optimal MR dampers are also experimentally tested. The test results show that the output damping force of initial and optimal MR dampers is 3.13 kN and 5.98 kN respectively under the applied current of 1.8 A, increasing by 91.1%, and the dynamic adjustable range is 11.5 and 16.1 respectively, increasing by 40.0%. It is found that the damping performance of the proposed MR damper is significantly improved. Show more

Keywords: MR damper, multiple axial fluid flow channels, optimal design, BP neural network, particle swarm optimization

DOI: 10.3233/JAE-210089

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-22, 2021

Authors: Huangfu, Youpeng | Wang, Shuhong | Yin, Shuli

Article Type: Research Article

Abstract: This paper presents a quantitative prediction model of conducted electromagnetic emissions (EME) for a variable frequency drive (VFD) motor system based on the macro-modeling approach. This model relies on the effective representations of the frequency dependent characteristics of the parasitic behaviors between converter arms and heatsink, of shielded power cable, and of motor windings. The frequency dependent performances between converter arms and heatsink, and of the motor windings are obtained by processing measurement data. Then the vector fitting method (VFM) with passivity enforcement and circuit synthesis method are adopted to obtain the corresponding equivalent circuits. The equivalent circuit implementation of …shielded power cable is achieved by applying a node-to-node admittance functions (NAFs) model, which considers the propagation phenomenon and frequency dependent losses accurately. The conducted EME model is compatible with commonly used transient circuit solvers since it only includes constant circuit elements. The conducted emissions of the VFD system are then evaluated by analyzing the common mode (CM) and differential mode (DM) voltages and currents. Show more

Keywords: Conducted emissions, frequency dependent, macro-modeling, variable frequency drive

DOI: 10.3233/JAE-210036

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2021

Authors: Li, Changyun | Yu, Yongjin | Kong, Xu

Article Type: Research Article

Abstract: In this paper, the mechanical properties of nano-silica modified insulating paper under the combined action of mechanical vibration and temperature conditions are studied. Unmodified and nano-silica modified cellulose insulating paper with 2 wt% and 4 wt% were prepared, respectively, and a series of mechanical-thermal synergy experiments were carried out. With the same mechanical stress and temperature, and with the same aging duration of 144 h (6d), the tensile strength of modified insulating paper with 4 wt% nano-silica, increased 9.9 N and 5.5 N, respectively, compared with those of the unmodified and the 2 wt% nano-silica modified insulating paper. The experiments indicate that the nano-silica modification can effectively …improve the mechanical properties of insulating paper. In this work, the modified mechanism of nano-silica is analyzed from the interface effect of modified polymer and the quantum effect of the modified polymer interface two aspects. It is shown that the interface formed in the modified insulating paper can transfer the mechanical stress acted on the insulating paper and prevent the cracks formed in the aging process of the test sample from further expansion, while the quantum effect discretizes the electron energy level, which can restrict the motion of the molecular chain segment to some extent. The conclusion can be used for reference to improve the performance of insulating paper. Show more

Keywords: Degree of polymerization (DP), mechanical-thermal synergy, nano-silica particle, tensile strength (TS)

DOI: 10.3233/JAE-210027

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021

Authors: Wang, Tingting | Xu, Lizhong | Xing, Jichun

Article Type: Research Article

Abstract: In this paper, the structural design and driving mechanism of a non-contact piezoelectric motor modulated by electromagnetic force are introduced. The equations of the electromagnetic force and torque of the electromagnetic modulation mechanism for the motor are deduced. Based on the piezoelectric constitutive equation and torque balance equations of the driving system, the equation of the piezoelectric driving torque is also obtained. Using these equations, the influences of the related parameters on the relationship between electromagnetic torque and angle difference between pole and rotor are studied. The influences of the main parameters and signal frequency on piezoelectric driving torques are …analyzed. Based on them, the torque optimization of the motor is completed and the load-carrying ability of the motor is increased by about 50 times. A prototype of the motor is developed. Its output torque is tested and compared with calculated one which illustrates the theoretical model here. Show more

Keywords: Torque, piezoelectric motor, non-contact, modulated by electromagnetic force

DOI: 10.3233/JAE-210043

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2021

Authors: Xiong, Qi | Song, Xianqi | Yang, Meng | Zhou, Lijun | Li, Zhe | Zhu, Xinhui | Zhi, Li

Article Type: Research Article

Abstract: Magnetic targeted drug delivery systems can improve drug utilization and reduce drug side effects. There are still many difficulties to be overcome in clinical practice. The main problems include providing large enough magnetic capture particles to concentrate drug-loaded magnetic micro-nanoparticles (MNPs) to the lesion site. The existing research focuses on the development of targeted carriers, and the magnet device has not formed a mature research system. Based on the recent development of magnet devices in recent years, this paper proposes the research direction of potential magnet devices. From the dynamic behavior of the particles under the magnetic field, the magnetic …system and the mathematical model design direction of the optimized magnet are developed. This article describes the obstacles encountered in drug targeting in the study of magnet devices and summarizes the potential development of future magnet devices. Show more

Keywords: Magnetic targeted drug delivery system, magnet device, targeted behavior

DOI: 10.3233/JAE-210021

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-17, 2021

Authors: Ye, Kuan | Zhou, Kai | Zhigang, Ren | Zhang, Ruizhe | Li, Chunsheng | Sun, Hongyu | Huang, Songling

Article Type: Research Article

Abstract: The power transmission tower’s ground electrode defect will affect its normal current dispersion function and threaten the power system’s safe and stable operation and even personal safety. Aiming at the problem that the buried grounding grid is difficult to be detected, this paper proposes a method for identifying the ground electrode defects of transmission towers based on single-side multi-point excited ultrasonic guided waves. The geometric model, ultrasonic excitation model, and physical model are established, and the feasibility of ultrasonic guided wave detection is verified through the simulation and experiment. In actual inspection, it is equally important to determine the specific …location of the defect. Therefore, a multi-point excitation method is proposed to determine the defect’s actual position by combining the ultrasonic guided wave signals at different excitation positions. Besides, the precise quantification of flat steel grounding electrode defects is achieved through the feature extraction-neural network method. Field test results show that, compared with the commercial double-sided excitation transducer, the single-sided excitation transducer proposed in this paper has a lower defect quantization error in defect quantification. The average quantization error is reduced by approximately 76%. Show more

Keywords: Transmission tower, ground electrode, Lamb wave, defect detection, feature extraction-neural network

DOI: 10.3233/JAE-210039

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2021