Flux 2D Research Articles

A STUDY OF SUBSURFACE OUTFLOW OF PERMEABLE FRICTION COURSE PAVEMENT BASED ON FINITE ELEMENT ANALYSIS

Permeable friction course pavement is designed with high porosity so that water can infiltrate into its pores and drain out laterally through the side. This study observes the subsurface outflow of a permeable friction course pavement via the finite element analysis program SV Flux 2D. A series of analyses were conducted for the permeable friction course pavement with different slope and rainfall intensity values. The results showed that different slope values provided different results for the subsurface outflow. As the slope increased, the subsurface outflow of the permeable friction course pavement increased. It is noticed that the effect of slope on the subsurface outflow decreased when the slope increased from 6% to 8%. In addition, this study also found that as the time of rain events increased, the subsurface outflow pavement was reduced. The investigation of the effect of rainfall intensity on the subsurface outflow of the permeable friction course pavement showed that as the rainfall intensity increased, the subsurface outflow steadily increased. However, it is noted that at the higher rainfall intensity, the pavement became saturated faster and the overflow happened earlier. In the future, further studies focused on the drainage of permeable friction course pavement including subsurface and surface outflow should be carried out.

Control mechanism of unbalanced magnetic pull in doubly fed induction generator using extra pole‐specific stator windings

The doubly fed induction generator is commonly used in commercial wind turbines because of its simplicity and robustness; it is a wound rotor induction machine. It has a relatively small airgap which makes it more vulnerable to unbalanced magnetic pull. This paper presents a simulation model to investigate the ability of extra stator windings with pm ± 1 pole-pairs to control the unbalanced magnetic pull (UMP). These auxiliary windings are inserted in the stator slots and they are used to produce counteracting flux that reduces the UMP. In the theory section, an UMP control matrix is fully developed that involves additional winding currents for obtaining active UMP control. The algorithm for controlling the UMP is then introduced. This uses vector control with stator flux orientation. Several simulations are carried out using MATLAB and Altair Flux 2D finite element analysis. These show a good reduction of UMP under open circuit and locked rotor tests. These models allow the study of the combined effects of radial forces with changes in the machine design. It was found that the average power absorbed by the auxiliary windings equals 13% of the total power losses in normal operation conditions.

Effect of Slot-Pole Numbers on the Performance of a BLDC Motor for Agro-EV Application

This paper analyzes the performance of a brushless direct current (BLDC) motor for agro electric vehicle (agro-EV) applications. Agro-EV technology is being developed in response to increasing environmental pollution. Various types of electric motors are in agro-EV, one of which is the BLDC. With its good capabilities, it has been chosen for further exploration in this research. On the other hand, some issues limit the usage of the conventional BLDC motor in heavy applications, such as low torque performance caused by weak magnetic energy. Therefore, this research aims to analyze the effect of magnetic energy based on slot-pole combinations to evaluate the BLDC motor's performance. Three BLDC models with different slot-pole numbers are designed and simulated using a fixed structure size, permanent magnet volume, and magnetomotive force (MMF). Finite element method (FEM) software known as Altair Flux 2D is used to compute the cogging torque, back-electromotive force (BEMF), magnetic flux density, and the torque produced. As a result, an 18/20 slot-pole was chosen for its high torque (105 Nm) and BEMF (35.9 V). In conclusion, this research simulation presents guidelines and an overview regarding the effect of slot-pole numbers on the performance of the BLDC motor for agro-EV applications.

A New Design Procedure for Rotor Laminations of Synchronous Reluctance Machines with Fluid Shaped Barriers

A new procedure for the design and optimization of the rotor laminations of a synchronous reluctance machine is presented in this paper. The configuration of the laminations is symmetrical and contains fluid-shaped barriers. The parametrization principle is used, which executes variations in the lamination geometry by changing the position, thickness and shape of the flux barriers. Hence, the optimization procedure analyzes the various configurations through finite element simulations, by means of the communication between MATLAB and Flux 2D. In the post processing stage, the best geometry which optimizes mean torque, torque ripple, efficiency and power factor is selected. Once the best rotor configuration is defined, further investigations allow improving its performance by modifying the current angle, the stator winding and the thickness of the radial ribs.

Design and electromagnetic analysis of switched reluctance linear generator in electric vehicle

The structural characteristics and basic design requirements of design of switched reluctance linear generator are introduced. According to the general principles and design experience of electromechanical design, the dimension of design of switched reluctance linear generator is determined, and the two-dimensional and three-dimensional static finite element models of design of switched reluctance linear generator are established in Flux 2D and Flux 3D respectively. By comparing the simulation results of the two-dimensional model and the three-dimensional model, it is found that the difference between the real simulation results of the 2D model and the 3D model is small, and the calculation time cost of the 2D finite element simulation is much lower than that of the 3D model. Therefore, the subsequent work of this paper adopts the 2D finite element model. Finally, the static electromagnetic field and electromagnetic characteristics of the design of switched reluctance linear generator are analyzed by finite element analysis.

Design and Analysis for Higher Torque Constant of Brushless Motor for High Volume Low Speed Fan

This paper deals with the design and analysis for torque constant characteristics of Brushless AC motor (BLAC) for High Volume Low-Speed Fan (HVLS). The torque constant characteristic of a BLAC motor is important to ensure higher torque performance concerning the input current. Through a previous study, the necessity of torque constant characteristic of BLAC to achieve optimum performance motor is still limited. Therefore, this paper aims to analyze the torque constant characteristic of BLAC for HVLS fan applications. Three models of BLAC motor with finite permanent magnet volume and magnetomotive force (MMF) have been simulated in order to evaluate the performances of BLAC motor. Commercial Finite Element Analysis (FEA) known as Flux 2D has been used to compute the back-electromotive force (Back-EMF), cogging torque, and transient torque in order to analyze the torque constant characteristic of different slot and pole numbers. As a result, the design of the BLAC motor for 18/20 has been chosen due to higher torque constant compared to others. As a conclusion, this research provides guidelines and an overview of designing a BLAC motor for HVLS fan application.

Electromagnetic and Mechanical Analysis of a Modular Outer Rotor Synchronous Reluctance Machine for Light Propulsion Vehicles

This article presents the optimal design from the electromagnetic and structural point of view of a fault-tolerant modular outer rotor synchronous reluctance machine, a not previously constructed topology. Two new topologies with the rotor in modular construction, one with each pole of the rotor considered as a separate module and a segmented one where each rib of a module can be considered as independent, are compared with a classic structure. The electromagnetic analysis is carried out using FLUX 2D software. The main studied parameters are electromagnetic torque, torque ripple content, saliency ratio, and power factor. In order to optimize the power factor of the machine, a cosimulation procedure is carried out for each structure, by employing a MATLAB and FLUX 2D coupling. Based on the obtained performances, the best topology is selected. Furthermore, a mechanical analysis is performed to determine if the new proposed rotor meets the structural integrity at rated speed and to establish the maximum speed value that can be attained such that the structural failure of the rotor is prevented. A modular outer rotor synchronous reluctance machine is designed and built. Experimental results of testing the prototype are given to confirm the validity of the proposed machine.

Finite element design and thermal analysis of an induction motor used for a hydraulic pumping system

In our day-to-day applications, we are using so many electrical motors. In those, Induction motor (IM) is the most used one in domestic and industrial applications. Mainly the Induction motors are used for water hydraulic pumping system in domestic applications. In Agriculture also, it plays a significant role. The induction motor needs to run for a very long time in such circumstances. It is very significant from the perspective of agricultural production. Mostly because of this continuous operation, the motor tends to get overheated. It will damage the motor if the condition persists. Therefore, the cooling of the induction motor becomes mandatory. For efficient cooling, the fin arrangement is provided over the induction motor. Thus, by adding fins, the heat dissipation surface area for convective heat transfer gets increased, and through natural convection, the motor temperature gets reduced. In the present work, the thermal analysis of induction motor is investigated by means of varying the total number and height of the fins. In this regard, the induction motor used for pumping system is designed by using the Flux 2D software package. And also, thermal analysis is carried out by using Finite element software packages Motor-CAD and ANSYS.

Analysis on EMF characteristics for torque ripple reduction in BLAC motor intended for HVLS fan application

This paper analyzes the harmonic characteristics of electromagnetic force (EMF) in Brushless Alternating Current (BLAC) motor for High Volume Low Speed (HVLS) fan application. Vibration and noise are one of the main crucial things in HVLS fan application. It comes from torque ripples which can be detected by harmonics of Electro Magnetic Force (EMF). Commonly, there are a few methods to eliminate the noise and vibrations issue, but most literatures only focus on small motor and not intended for HVLS fan application. Thus, the objective of this paper is to eliminate the harmonics content in EMF at early stage design. Through EMF harmonics the expected torque produced could be used to select proper slot-pole number in order to eliminate the noise and vibrations issue. In here, the analysis involves three different slot-pole numbers which are 18s/20p, 12s/10p and 9s/8p BLAC model, respectively. All models have similar volume of permanent magnet. The analysis is carried out using FLUX 2D Finite Element Analysis (FEA) for EMF computational and transient torque computation. Later, Fast Fourier Transform (FFT) analysis is used to calculate the harmonics of EMF. The analysis stage includes the EMF parameter analysis, harmonics and torque ripples analysis. It was found that 18s/20p has higher output torque with the lowest 5% torque ripple value. As a conclusion, this paper presents low torque ripple in point of view of the EMF characteristics in designing HVLS fan.

New approach to study HTS bulk behavior for a fully superconducting motor design

The originality of this work is to applied Amperian Approach for modelling HTS bulk especially in electrical motor applications. This approach has proven its efficiency in electrical materials having a constant conductivity. For HTS materials, the resistivity change brutally and have a non linear comportment through any external magnetic field variations. To success the modelisation, we have to create an iterative procedure. All simulation steps are based on the power law model for computing resistivity and current densities adding the fixed point method for non linear iterations. The majority of our results concern the current densities in the HTS bulk rotor with different critical currents constatations under mgnetic field created by three phase coils of the proposed superconducting synchronous motor (SSM) prototype. Some results are consolidated by numerical way using flux 2D software.

Optimal rotor design of novel outer rotor reluctance synchronous machine

This paper presents the optimal design and performance analysis of a novel synchronous reluctance motor with outer rotor for determination of the effect of the rotor pole shape on the machine’s performances. The investigation has been made in order to find the possible ways to improve the power factor with refining the rotor geometry without using permanent magnets. Starting from the design of the machine with classical rotor pole that was implemented in FLUX 2D, a finite element analysis software coupled with an optimal design procedure implemented in MATLAB was performed. The purpose of this complex co-simulation was to obtain several outer rotor structures that increase the performances of the machine: saliency ratio, power factor and torque density. For the proposed structures, especially for the modular topology, the obtained results of saliency and power factor have never been presented in the past literature. Hence, this represents a useful starting point for the following analysis of outer rotor synchronous reluctance machines with improved power factor.

Understanding Microstructural Evolution During Rapid Heat Treatment of Microalloyed Steels Through Computational Modeling, Advanced Physical Simulation, and Multiscale Characterization Techniques

An AISI 1045 steel modified with vanadium (V) and niobium (Nb) was studied to evaluate microstructural conditioning prior to and throughout a rapid heat treat process. In order to accomplish this, both computational and physical simulation techniques have been employed with the goal of assessing the microstructural evolution in a medium-carbon bar steel during the rapid austenitization and quenching procedures involved in an induction hardening process. The appropriate thermal profiles for induction hardening were obtained through finite element modeling using Flux 2D software. Physical simulations of the induction hardening process were carried out using a Gleeble® 3500. Analysis of prior austenite grain size is complemented by observation of nanoscale carbonitride precipitation via transmission electron microscopy, scanning transmission electron microscopy, and high-energy synchrotron small-angle x-ray scattering. Through a combination of characterization techniques, this study presents a deeper understanding of nano- and microstructural changes occurring in a microalloyed steel during an induction hardening process.

An analysis of power losses in nanocrystalline and thin-gauge non-oriented SiFe materials for application to high-speed electrical machines

In this paper, the potential of thin sheet SiFe NO20 and nanocrystalline materials for the realization of the magnetic circuit of high-speed machines is analyzed in a complete procedure. Firstly, intrinsic properties of materials are precisely characterized. Next, the original and a modified model of Bertotti are applied for the modeling of power losses. These models are then used to predict losses in a simplified test bench which simulates the magnetic core of a real machine. FEM simulations in Altair FLUX 2D and experimental measurements are respectively carried out and results obtained show a good agreement leading to the confirmation of the potential of materials and the validation of the realized procedure.

Study of the influence of nonlinear parameters on the efficiency of a resistive field grading tube for cable termination

The aim of this paper is to investigate the influence of nonlinear parameters (threshold field, low field conductivity and nonlinearity coefficient) on the performance of a cable termination equipped with a resistive field grading tube at 50 Hz and impulse voltage. The electrical field distribution over the insulator silicone housing surface was computed and analyzed using a finite element software (Flux 2D). Comparative studies between linear field grading (er = 2.9 and 16) and nonlinear resistive field grading (12 < er < 19) show that better effectiveness is achieved with a low threshold field and a high permittivity under 50 Hz and a high nonlinearity coefficient under impulse voltage.

Capability of new multi-segment winding configurations in HTS transformer to mitigate electromagnetic forces under short-circuit condition

The consequences of short-circuit forces for high-temperature superconductor (HTS) transformers are much more detrimental than conventional ones. That is because on one hand, HTS windings have less mechanical robustness than copper ones and on the other hand, the effects of extreme axial forces on HTS windings are irreversible and may cause irreparable damages to HTS transformers. In this paper, capability of new concentric multi-segment winding configurations in HTS transformers, proposed in Ghabeli et al. (2015), to mitigate high axial and radial electromagnetic forces due to short-circuit fault is investigated. The studied winding configurations include concentric PSP (Primary-Secondary-Primary), symmetrical and asymmetrical PSPSP (Primary-Secondary-Primary-Secondary-Primary). The study is realized with an advanced numerical method using accurate and nonlinear E-J power law via FEM-based software Flux 2D. Profiles of axial and radial electromagnetic forces in each sub-winding have been presented, analyzed and compared to each other in detail. For accurate calculation of axial and radial forces in each sub-winding, a collection of points along the longitudinal and transverse axes in the center of each sub-winding was considered. The maximum of radial and axial electromagnetic forces decrease remarkably in PSPSP winding configuration compared to PSP winding configuration. In addition, the asymmetrical winding configurations mitigate these forces more than symmetrical ones.

Striation effect in induction heating: myths and reality

PurposeEffect of unstable “wavy” temperature distribution on the part surface during the process of induction heating of ferromagnetic materials was observed and reported by two Russian scientists in 1940 (Babat and Lozinskii, 1940). They reported that under certain conditions, one can observe periodical or quasi-periodical bright stripes on the part surface when its temperature passes through the Curie point. In time, these stripes expand and merge, forming a normal temperature pattern. They called this phenomenon “polosatiy nagrev” (striation heating). Let us call it the “zebra effect” for simplicity. It can exist for a relatively long time, from several seconds to several tens of seconds. Several explanations of the zebra effect were proposed with not very convincing arguments. The purpose of this study is to improve the understanding of this effect.Design/methodology/approachWider spreading of induction technology and use of computer simulation of induction processes create a demand and open new possibilities for study of the zebra effect. This study provides an overview of the available information about the zebra effect and gives new explanation of this phenomenon based on existing experimental data and new results of simulation. Conditions for zebra occurrence and its technological importance or limitations are discussed.FindingsComputer simulation using the Flux 2D program allows to demonstrate the striation (zebra) effect that can appear in the process of heating magnetic materials and reproduce main experimental findings related to this effect. Simulation provides a great opportunity to investigate the zebra phenomenon in virtual reality, providing qualitatively correct results. Results of simulation show that the zebra effect can appear in a relatively narrow range of material properties and operating conditions. The main factor is a big enough gradient of permeability near the Curie point. At present, it is difficult to expect high quantitative accuracy of simulation due to multiple assumptions in simulation algorithms and insufficient or inaccurate information about the material properties near the Curie point.Originality/valueSeveral explanations of the zebra effect were proposed with not very convincing arguments. There were concerns that the zebra effect could set significant limits on the use of induction heating for surface hardening due to non-uniform temperature distribution along the part (Babat and Lozinskii, 1940; Babat, 1965; Lozinskii, 1949, 1969). However, it did not happen. There were no complaints from scientists or practitioners regarding any negative effect of the zebra phenomenon. Moreover, the authors of this paper did not find any original publications on this issue for more than half a century. Only few old induction experts confirm that they observed the zebra effect or something similar, whereas a great majority of induction community members never heard about it.

Analysis of Continuous Induction Hardening of Steel Cylinder Element Made of Steel 38Mn6 / Analiza Przelotowego Hartowania Indukcyjnego Walca Ze Stali 38Mn6

The paper presents analysis of surface induction hardening of a cylindrical element made of steel 38Mn6. The mathematical model of the non-stationary process is elaborated. Calculations of coupled electromagnetic and temperature fields are provided by means of the Flux 2D software. Computations are compared with the measurements realized at the laboratory stand located in the Silesian University of Technology. The expected hardness distribution within the surface layer is noticed.

Design and characterisation of magnetorheological brake system

This paper investigates the performance of a magnetorheological brake (MR brake) system in terms of torque generated by various electric currents at various rotational shaft speeds. The MR brake consists of a rotating disc immersed with magnetorheological fluid (MR fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid, which will decrease the speed of the rotating shaft. Then, different speeds were applied to the MR brake system continuously by changing the applied electric current. The methodology begins with the design using 3D modelling software followed by the development of a mathematical model of the MR brake. Then, magnetostatic analysis using ANSYS software was done by considering three parameters, which are magnetic field intensity, magnetic flux density and 2D flux lines. The torque response of the MR brake from the simulation was validated with experimental results and discussed. It can be noted that the MR brake torque increases proportionally with the increase in current and independent with varying speeds.

A comparative study of synchronous reluctance and switched reluctance motors for high-performance fault-tolerant applications

In this paper, a new power converter with redundant topology is proposed to compare the fault tolerance capability in terms of the torque density of a 6/4 conventional switched reluctance motor (SRM) and a synchronous reluctance motor (SynRM) that uses an axially laminated rotor. The simulation of the converter is achieved through an equivalent electrical circuit built into the circuit editor, CIRFLU, coupled to the finite elements model (FEM) of the machine using FLUX 2D software package. A numerical approach by FEM allowsafiner analysis of the phenomena intransient and non-linear mode. Simulations of various defects were used to compare the performance of two machines for fault-tolerant applications. The theoretical results compared with the experimental ones existing in the literature prove the effectiveness of this study.

Simulation of Temperature Field Induced in Localized Ultra-High Frequency Induction Brazing of Diamond Tools

Localized ultra-high frequency induction brazing is proposed to deal with the thermal deformation problem of brazed diamond tools. In order to investigate the temperature field distribution, the simulation model of induction brazing for solving the temperature field is described through the FLUX 2D software. The experiment is carried out to verify the numerical simulation result. Good agreement is observed between experimental value and simulation result. The influence factors on temperature field are investigated by the simulation software. Ultra-high frequency induction brazing with diamond grits is carried out based on the conditions given by simulation results. Good bonding between the diamond grits and the filler alloy is observed and the width of the brazed region is less than 3 mm.