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

Authors: Wang, Jing | Song, Haicheng | Tomizawa, Takuma | Yusa, Noritaka | Ling, Yuanjin

Article Type: Research Article

Abstract: It is still a big challenge to calculate the probability of defect detection for inspecting pits on austenitic stainless steel welding using traditional POD models. Because we determine the decision threshold, the POD curve has a lot of changes as the decision threshold changes, there is no clear reason to insist which threshold is reasonable. This study proposes a new probability of detection (POD) model to quantitatively assess the detection capability of eddy current probes for inspecting pits on austenitic stainless steel welding. The experimental results show that the proposed model is more reasonable than traditional ones. The novel POD …model was employed to analyze three eddy current probes, uniform, TR, plus-point probes on austenitic stainless steel welding. The results reveal that the uniform eddy current probe has the best detection capability for inspecting pits on among the three probes. Show more

Keywords: Eddy current testing, probability of detection, stochastic decision threshold, austenitic stainless steel welding

DOI: 10.3233/JAE-201602

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

Authors: Eldabe, Nabil Tawfik | Moatimid, Galal M. | Abouzeid, Mohamed | El-Shekhipy, Abdelhafeez A. | Abdallah, Naglaa Fawzy

Article Type: Research Article

Abstract: In the current paper, a semi-analytical solution is obtained for the problem of the peristaltic motion of Jeffrey nanofluid with heat transfer inside an asymmetric channel. The influences of variable viscosity, thermal conductivity, Hall currents, Joule heat and viscous dissipation are taken into consideration. The problem is modulated mathematically by a system of non-linear partial deferential equations which describe the fluid velocity, temperature and nanoparticles concentration distributions. This system is simplified by considering long wavelength of the peristaltic wave and low Reynolds number. It is solved by using the multi-step deferential transform method to obtain the velocity, temperature and nanoparticles …concentration distributions, pressure rise and pressure gradient. These solutions are obtained as functions of the physical parameters of the problem. Tables and figures are discussed to see the effects of these parameters. It is found that the thermal conductivity parameter causes an increase in the pressure gradient, meanwhile it reduces the pressure rise. Furthermore, it is noticed that the behavior of Brownian and thermophoresis parameters on nanoparticles concentration field are quite reverse. Show more

Keywords: Peristaltic flow, Jeffrey nanofluid, Hall currents, Joule heating, Mathematica 11

DOI: 10.3233/JAE-201626

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

Authors: Swiatkowski, Michal | Witczak, Pawel

Article Type: Research Article

Abstract: The aim of this paper is to present the impact of the leakage flux on magnetic shunts and tank walls of power transformers from vibrational point of view. The experimental studies of the large power transformers show that tank vibrations and the resulting acoustic emission at load condition are significantly higher than at no-load condition. The paper presents 3D finite elements model in electromagnetic domain used for the analysis of magnetic forces applied to shunts at rated short circuit state which are the origin of tank vibration. The main finding of the work is that forces equivalent to the magnetostriction …deformation of the shunt interior are comparable with magnetic forces resulting from the stray field and applied to the shunts’ surface. Show more

Keywords: Power transformer, magnetic shielding, magnetic flux leakage, magnetic and magnetostriction analysis

DOI: 10.3233/JAE-201622

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2021

Authors: Wang, Geng | Gao, Renjing | Wang, Qi | Liu, Shutian

Article Type: Research Article

Abstract: Electromagnetic linear actuators (ELAs) may be confronted with unsatisfactory performance when subjected to overheating. Therefore, it is significant to clarify its thermal characteristics and design the thermal performance requirements. A thermal analysis method based on multiphysics coupling model was presented, which uses the non-simplified loss distribution as the heat source to calculate the temperature field, adjusts the material properties by temperature, and considers the interaction between motion (including impact) and loss. More importantly, an improved universal equivalent winding to satisfy the condition of real compact concentrated winding was developed. Finally, the validity of this approach was verified through the experiment, …and the regularity of temperature was summarized. The results show that the error of simulation and experiment is less than 6% and the permissible continuous operation frequency is no more than 30 Hz. The approach proposed in this paper can be employed not only to the ELA, but also to the design and analysis a wide range of electromagnetic machines. Show more

Keywords: Electromagnetic linear actuator, equivalent winding, multiphysics coupling model, thermal analysis method

DOI: 10.3233/JAE-201586

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

Authors: Ouaf, Mahmoud E. | Abou-zeid, Mohamed Y.

Article Type: Review Article

Abstract: The purpose of this paper is to investogate the ectromagnetic and micropolar properties on biviscosity fluid flow with heat and mass transfer through a non-Darcy porous medium. Morever, The heat source, viscous dissipation, thermal diffusion and chemical reaction are taken into consideration. The system of non linear equations which govern the motion is transformed into ordinary differential equations by using a suitable similarity transformations. These equations are solved by making use of Rung–Kutta–Merson method in a shooting and matching technique. The numerical solutions of the velocity, microtation velocity, temperature and concentration are obtained as a functions of the physical parameters …of the problem. Moreover the effects of these parameters on these solutions are discussed numerically and depicted graphically. It is found that the microtation velocity increases or deceases as the electric parameter, Hartman parameter and the microrotation parameter increase. Morever, the temperature increases as Forschheimer number, Eckert number increase. Show more

Keywords: Micro-polar fluid, heat and mass transfer, electromagnetic flow, non-Darcy porous medium

DOI: 10.3233/JAE-201623

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2021

Authors: Yu-dong, Xu | Cong, Li | Qiong-ying, Lv | Xin-ming, Zhang | Guo-zhen, Mu

Article Type: Research Article

Abstract: In order to study the effect of the trailing edge sweep angle of the centrifugal impeller on the aerodynamic performance of the centrifugal compressor, 6 groups of centrifugal impellers with different bending angles and 5 groups of different inclination angles were designed to achieve different impeller blade trailing edge angle. The computational fluid dynamics (CFD) method was used to simulate and analyze the flow field of centrifugal compressors with different blade shapes under design conditions. The research results show that for transonic micro centrifugal compressors, changing the blade trailing edge sweep angle can improve the compressor’s isentropic efficiency and pressure …ratio. The pressure ratio of the compressor shows a trend of increasing first and then decreasing with the increase of the blade bending angle. When the blade bending angle is 45°, the pressure ratio of the centrifugal compressor reaches a maximum of 1.69, and the isentropic efficiency is 67.3%. But changing the inclination angle of the blade trailing edge has little effect on the isentropic efficiency and pressure ratio. The sweep angle of blade trailing edge is an effective method to improve its isentropic efficiency and pressure ratio. This analysis method provides a reference for the rational selection of the blade trailing edge angle, and provides a reference for the design of micro centrifugal compressors under high Reynolds numbers. Show more

Keywords: Centrifugal compressor, bending angle, inclination angle, pressure ratio, isentropic efficiency

DOI: 10.3233/JAE-201590

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

Authors: El-dabe, Nabil T. | Abou-zeid, Mohamed Y. | Mohamed, Mona A. | Maged, Mohamed

Article Type: Research Article

Abstract: In this work, we focused on the peristaltic unsteady flow of non-Newtonian nanofluid with heat transfer through a non-uniform vertical duct. The flow obeys Herschel Bulkley model through a non-Darcy porous medium under the effects of mixed convection and thermal diffusion. Moreover, the effects of thermal radiation, heat generation, Ohmic dissipation, chemical reaction and uniform external magnetic field are investigated. The derived equations that describe the velocity, temperature and nanoparticles concentration are simplified under the assumptions of long wave length and low Reynolds number. These equations have been solved by using a numerical technique with the help of shooting method. …The obtained solutions are functions of the physical parameters entering the problem. The effects of these parameters and the obtained solutions are explained and discussed through a set of graphs. It is found that the increment in Prandtl number or Thermophoresis parameter reduces the spread of the nanoparticles (concentration increased) within the fluid along with the thermal diffusivity through the fluid layers. Also the non-Darcy effect supports the inertial forces, and in order to maintain Reynolds number, the viscous forces are motivated and the axial velocity is damped. Moreover, for the validation of the current methodology, this model is reduced to power law model (no yield stress) and compared with the work of Eldabe et al. [16 ]. Show more

Keywords: Peristaltic flow, Herschel Bulkley model, nanofluid, thermal diffusion, mixed convection, chemical reaction

DOI: 10.3233/JAE-201600

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

Authors: Maharani, Elliza Tri | Ubaidillah, U. | Imaduddin, Fitrian | Wibowo, K.M. | Utami, Dewi | Mazlan, Saiful Amri

Article Type: Research Article

Abstract: An experimental study was undertaken to evaluate the mathematical modelling of the magnetorheological (MR) damper featuring annular radial gap on its valve. The experiment was conducted using a fatigue dynamic test machine under particular excitation frequency and amplitude to get force-velocity and force-displament characteristics. Meanwhile, the mathematical modelling was done using quasi-steady modelling approach. Simulation using adaptive neuro fuzzy inference (ANFIS) Algorithm (Gaussian and Generalized Bell) were also carried out to portray the damping force-displacement modelling that is used to compare with the experimental results. The experimental characteristics show that amplitudes excitation and current input affect the result damping force …value. The comparison of the experimental and mathematical results presented in this paper shows a significant difference in damping force value and that the quasi-steady modelling could not significantly approach the damping force-velocity results. Moreover, the semi-active damper is compared to the passive damper. The results show that a semi-active damper performs better than a passive damper because it only requires a little power. Based on the damping force-displacement modelling, it can be seen that Gaussian has a higher accuracy rather than Generalized Bell. Discussion on the energy dissipation and equivalent damping coefficient were also accomodated in this paper. Having completed in mathematical modelling and simulation, the damper would be ready for further work in-vehicle application that is development of control system. Show more

Keywords: MR damper, annular-radial MR valve, quasi-steady modelling, MR damper characteristics, energy dissipated, ANFIS Algorithm

DOI: 10.3233/JAE-201560

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2021

Authors: Fan, Chen | Chongfeng, Zhang | Xiaolong, Yang

Article Type: Research Article

Abstract: In order to solve the problem of short service life (2 months) and zero leakage of air cylinder in aerospace engineering, this paper innovatively designs a magnetic fluid sealing device of air cylinder in aerospace engineering through magnetic circuit analysis and magnetic fluid sealing theory. The magnetic field finite element method is used to calculate the magnetic field distribution in the sealing gap under different key parameters such as the number of pole teeth, the height of the radial sealing gap, the thickness of the permanent magnet, the slot width, the ratio of pole piece height to shaft. And numerical …analysis of the number of pole teeth, the radial sealing gap height, permanent magnet thickness, slot width, the ratio of pole piece height to shaft and other key parameters on the magnetic fluid sealing performance. Finally, the reliability of the reciprocating magnetic fluid sealing withstand voltage is verified by experimental methods. Research indicates. The pressure capabilities of magnetic fluid sealing is increasing with the increase of the number of pole teeth. The pressure capabilities of magnetic fluid sealing is decreasing with the increase of the radial sealing gap. The sealing withstand voltage increases first and then decreases with the increase of the thickness of the permanent magnet, and finally increases, and the value of the withstand voltage is the largest when the thickness of the permanent magnet is 7.8 mm. The sealing pressure capabilities increases as the slot width increases. The sealing withstand voltage increases first and then decreases as the ratio of pole piece height to shaft increases, and when the ratio of pole piece height to shaft is 0.8, the sealing withstand voltage reaches a maximum value. The pressure test finally reaches the pressure value of 6 MPa, which can meet the pressure value demand of medium pressure cylinder, indicating that the magnetic fluid sealing technology can effectively solve the leakage problem existing in the air cylinder technology of Aerospace Engineering, and improve the reliability and service life of the air cylinder. Show more

Keywords: Aerospace engineering, air cylinder, magnetic fluid sealing, numerical analysis, key parameters, experiment

DOI: 10.3233/JAE-201572

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

Authors: Zhang, Jin | Wang, Xin | Wang, Xuebing | Zheng, LingLing | Li, Ruipeng | Lu, Chao | Shi, Wenze

Article Type: Research Article

Abstract: Due to the poor conversion efficiency and signal-to-noise ratio (SNR) of Electromagnetic Acoustic Transducer (EMAT) testing, the defect detection sensitivity is limited, which restricts the extensive industrial applications. A finite element model for the testing process of a meander-coil EMAT was established that considers the simplified excitation and detection circuits for the EMAT. Based on this model, the effect of the connection methods (parallel or series) of the coils in the generating and receiving EMATs on their generating and receiving efficiency was investigated, and the simulation results were validated experimentally. Subsequently, the pulse compression technique with a 13-bit Barker code …was used for the EMAT detection, and improvements of the SNR and range resolution were established through numerical simulation and experimental measurement. The results show that compared with the traditional EMAT design, which comprises single-layer transmitting and receiving coils, the conversion efficiency of the optimized EMAT with two excitation and receiving coils in the parallel connection can be improved by 52.8%. With the application of the Barker-coded pulse compression to detect the ultrasonic A-scan signal with no synchronous average, the SNR of the defect echo can be improved by 9.5 dB compared with the A-scan signal with 128 synchronous averages. Show more

Keywords: EMAT, surface wave, conversion efficiency, pulse compression, Barker code

DOI: 10.3233/JAE-201609

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-23, 2021