Thrust Force Research Articles

Finite Element Analysis of Different Transverse Flux Linear Induction Motor Models to Improve the Performance of the Main Magnetic Circuit

This paper delves into the knowledge of transverse flux linear induction motors using three-dimensional finite element simulation tools. Original linear induction motors have a useful magnetic flux perpendicular to the movement. We propose some geometric changes to improve the main magnetic circuit of the machine and to ensure simultaneous operation between longitudinal and transverse magnetic fluxes. To obtain the main parameters of the equivalent electrical circuit in a steady state, we propose two steps. Firstly, replicate the classic indirect tests used in rotating machines. This represents a significant advantage since it allows several models to be experimentally tested to obtain the values of electrical parameters. Secondly, use the data from these tests to solve a particular system of equations using numerical methods. The solution provides the electrical elements necessary to generate the equivalent circuit proposed by the authors. A quantitative analysis of the main electrical parameters is also carried out, confirming the advantages of the changes introduced. With them, a significant improvement in thrust force is obtained, especially in stationary conditions and low speeds. Finally, we study, in detail, a set of specific phenomena of linear machines using two parameters: the secondary equivalent air gap and the secondary equivalent conductivity.

Fish robotics: multi-fin propulsion and the coupling of fin phase, spacing, and compliance

Fish coordinate the motion of their fins and body to create the time-varying forces required for swimming and agile maneuvers. To effectively adapt this biological strategy for underwater robots, it is necessary to understand how the location and coordination of interacting fish-like fins affect the production of propulsive forces. In this study, the impact that phase difference, horizontal and vertical spacing, and compliance of paired fins had on net thrust and lateral forces was investigated using two fish-like robotic swimmers and a series of computational fluid dynamic simulations. The results demonstrated that the propulsive forces created by pairs of fins that interact through wake flows are highly dependent on the fins’ spacing and compliance. Changes to fin separation of less than one fin length had a dramatic effect on forces, and on the phase difference at which desired forces would occur. These findings have clear implications when designing multi-finned swimming robots. Well-designed, interacting fins can potentially produce several times more propulsive force than a poorly tuned robot with seemingly small differences in the kinematic, geometric, and mechanical properties.

Micro drilling characterization of the carbon and carbon–aramid (hybrid) composites

AbstractIn this study, micro‐drilling tests were carried out on composite laminates reinforced with hybrid (aramid‐carbon) and carbon fibers. Thrust force, hole quality, tool wear, and temperature parameters were measured and assessed following each drilling test. The quality of holes includes circularity, overcut, hole damage factor (HDF), and taper ratio. Micro‐drilling was performed on a CNC milling machine using 0.6 mm drill diameter, 7500 rpm, and 0.5 mm/min feed parameters. The plates are 3.05 mm (carbon fiber) and 3.45 mm (hybrid) thick. According to the results, the maximum thrust force (29.8 N) was measured in the hybrid composite due to the high fracture toughness of the aramid. In addition, it was determined that the thrust force and drill wear were related. The increase in thrust force during drilling caused an increase in drill wear values. While the average wear of the drill in carbon composite was 0.013 mm, the average wear of the drill in hybrid composite was 0.021 mm. Thrust force and tool temperatures were found to have a similar trend. The highest tool temperature was measured as 86.7°C in the hybrid composite. Hole quality results showed that drilling in carbon composite was more successful than in hybrid composite. Holes drilled in carbon composite have lower values for overcut (0.017 mm), HDF (1.028), and taper ratio (0.008). It has been understood that hole quality depends on thrust force and damage formation.Highlights Carbon and hybrid (carbon‐aramid) composites were produced with a vacuum infusion process (VIP). Micro‐drilling of composites was investigated focusing on thrust force, tool temperature, and hole quality. Hybrid composites exhibited greater thrust forces due to their higher toughness compared to carbon composites. Hybrid composites showed higher maximum tool temperatures compared to carbon composites. The carbon composites exhibited better hole quality compared to the hybrid composites.

Lab Scale Investigation of Gaseous Emissions, Performance and Stability of an Aviation Turbo-Engine While Running on Biodiesel Based Sustainable Aviation Fuel

The research experimentally examines the viability of biodiesel obtained from pork fat (BP) as a sustainable aviation fuel (SAF) when mixed with kerosene (Ke)—Jet-A aviation fuel + 5% Aeroshell 500 oil. Various blends of biodiesel and kerosene (10, 20, and 30% vol. of BP added in Ke) were subjected to testing in an aviation micro turbo-engine under different operational states: idle, cruise, and maximum power. During the tests, monitoring of engine parameters such as burning temperature, fuel consumption, and thrust force was conducted. The study also encompassed the calculation of crucial performance indicators like burning efficiency, thermal efficiency, and specific consumption for all fuel blends under maximum power conditions. Combustion temperatures ahead of the turbines rise with an increase in biodiesel concentration, particularly in the idle regime, without compromising engine integrity. However, for regimes 2 and 3, the temperature in front of the turbine decreases with rising biodiesel concentration, accompanied by an increase in fuel flow rate. This phenomenon is reflected in the elevated specific consumption. Notably, for regime 3, there is a noticeable rise in specific consumption, starting from S = 0.0264 kg/Nh when the turbo-engine operates solely with Ke, to S = 0.0266 kg/Nh for Ke + 10% BP, S = 0.0269 kg/Nh for Ke + 20% BP, and S = 0.0275 kg/Nh for Ke + 30% BP. Physical–chemical properties of the blends, encompassing density, viscosity, flash point, and calorific power, were determined. Furthermore, elemental analysis and FTIR were used for chemical composition determination. The amount of CO2 produced during the stoichiometric combustion reaction with air showed variations. Initially, when using only Ke, it amounted to 3.12 kg per kilogram of fuel. Upon adding 10% BP, this value decreased to 3.09 kg, further reducing to 3.05 kg with 20% BP. The lowest value was observed with 30% BP, reaching 3.04 kg. Experimental assessments were performed on the Jet Cat P80® micro-turbo-engine, covering aspects such as starting procedures, sudden acceleration, sudden deceleration, and emissions of pollutants (NOx, CO, and SO2) during several engine operational phases. The outcomes reveal that the examined fuel blends exhibited stable engine performance across all tested conditions. This indicates that these blends hold promise as sustainable aviation fuels for micro turbo-engines, presenting benefits in terms of diminished pollution and a more ecologically sound raw material base for fuel production.

Thermal-mechanical coupling in drilling high-performance CFRP: Scale-span modeling and experimental validation

The focus of this study is to explore a scale-span thermal–mechanical coupling method for predicting the dynamic mechanical progressive failure behaviors and predicting thermal damage during the drilling process of Carbon Fiber Reinforced Plastic (CFRP). Initially, a thermal conduction constitutive model of drilling CFRP was developed based on the proposed thermal distribution ratio calculation method. Meanwhile, a dynamic span-scale progressive damage constitutive model for CFRP, incorporating modified micromechanics failure criterion with bilinear damage evolution laws, was proposed, and a bilinear cohesive model, including three damage modes, is employed to simulate interlaminar delamination. Subsequently, a user-defined material subroutine VUMAT was implemented on the ABAQUS/Explicit platform to simulate the thermal–mechanical coupling behaviors of drilling T700S-12K/YPH-23 CFRP using a twist drill bit. Finally, a comprehensive information monitoring platform for CFRP drilling experiments was established to validate the accuracy of the simulation results by considering drilling temperature, thrust force, and hole-wall morphology. The results demonstrate excellent agreement between the established thermal–mechanical coupling span-scale model and the experimental data. Furthermore, the simulation effectively captures the various damage behaviors and thermal conduction phenomenon, that occur during the intact drilling process.

Introducing transversal vibration in twist drilling: Material removal mechanisms and surface integrity

In twist drilling, severe extrusion is unavoidable at the chisel edge zone and results in high thrust force and poor surface integrity. Traditional axial vibration-assisted twist drilling only modifies the material removed from the continuous extrusion to the interrupted extrusion for the chisel edge centre, and must satisfy the chip-breaking conditions to ensure that the cutting edge is periodically separated from the workpiece. Hence, transversal vibration, has been introduced in twist drilling to overcome the severe extrusion behaviour of the chisel edges of the twist drills, referred to as ultrasonic transversal vibration-assisted drilling (UTVD). Theoretical models revealed that the material removal behaviour of the chisel edge centre changed from extrusion in CD to cutting in UTVD. Experiments were performed on UTVD of Ti-6Al-4V to confirm the feasibility with this novel method. The results indicated that transverse vibration significantly affected the thrust force and torque, and the maximum decline was 29.4% and 31.5%, respectively, compared with CD. Generated chips verified the material removal behaviour of the chisel edge centre zone changed from extrusion in CD to cutting in UTVD. Therefore, the hole quality and surface integrity were improved significantly by UTVD. Deeper plastic deformation (∼2.5 times), higher surface microhardness and compressive residual stress were realised using UTVD. This study enhanced the understanding of material removal and formation mechanisms of the surface and subsurface in UTVD, thereby providing a novel method and theoretical basis for the high-performance twist drilling of difficult-to-cut alloys.

FE parametric evaluation of macro-to-microscale dry milling for sustainable manufacturing of aerospace alloys

Micro-end-milling of energy-efficient materials has gained prime significance in advanced manufacturing due to their excellent machining characteristics. Numerous experimental and numerical studies have been conducted to establish the optimum parameters of the micro-end-milling process. Because of the complex interaction at the tool-burr interface that involves high material strain rates, this study investigated an extensive parametric sensitivity analysis to evaluate the reliability of numerical simulations. The numerical simulations of AA2024 and Ti6Al4V alloy micro-end-milling are performed in Abaqus/Explicit using the thermo-viscoelastic Johnson-Cook damage model. The parametric sensitivity analysis of both materials is compared, and the burr morphologies are analyzed with changing material characteristics. Tool-burr interface temperature, cutting reaction forces, material plastic strain, and stresses are evaluated to analyze the effect of the change in material characteristics with cutting parameters. Computations are performed at different cutting speeds, tool edge radii, cutting feeds, and contact friction to analyze their effect on chip stress, temperature, material strain, and the tool's thrust force. Feed and contract friction demonstrated pronounced effects on the chip-tool interface temperature compared to the contact friction for both types of materials. The computational results are verified with the experimental data.

Burr constitution analysis in ultrasonic-assisted drilling of CFRP/nano-graphene via experimental and data-driven methodologies

In this study, a comprehensive investigation was undertaken to analyze the impact of various factors on thrust force and burr damage in carbon fiber reinforced polymer laminates during drilling operations. The factors examined included the incorporation of nano-graphene, the application of ultrasonic vibration, the type of cutting tool, and the feed rate. Statistical and machine learning techniques were employed to analyze the data, and image processing was utilized to illustrate the extent of burr damage surrounding the drilled holes. The developed model exhibited satisfactory prediction accuracy with minimal error rates. Statistical analysis revealed that the feed rate exerted the greatest influence on thrust force and facilitated the burr generation. Likewise, the addition of nano-graphene resulted in an increased thrust force due to improved rupture limits, consequently leading to cleaner holes with minimal burr damage. Furthermore, the implementation of ultrasonic vibration and the use of high-cobalt cutting tools were found to enhance drilling performance by reducing thrust force and minimizing the burr formation. The best hole quality was achieved at the lowest feed rate, in combination with a cutting tool containing 8% cobalt and the utilization of ultrasonic vibration.

Asynchronous distributed optimal power control for fatigue load minimization in wind farms

An asynchronous distributed optimal power control (OPC) scheme is proposed to minimize fatigue load in the wind farms (WFs) in this paper. To better satisfy the grid code, each wind turbine (WT) in the scheme is equipped with an energy storage system (ESS) at the DC link of the WT converter. Based on the WT topology, a WT-ESS control model is established, thus developing an OPC scheme to control the generator torque, pitch angle, and ESS output simultaneously for reducing fatigue load. By formulating the model predicted control (MPC)-based optimal problems, the virtual mechanical power control is proposed to regulate the ESSs output for clarifying the power interactions among WTs and ESSs. In order to achieve more effective control of the above three parameters among multiple WTs-ESSs, an asynchronous distributed alternating direction method of multipliers (AD-ADMM) is developed to simultaneously minimize the variations of thrust force, shaft torque, and flapping moment load of the WTs in a wider range. Considering the impact of communication delays, the proposed AD-ADMM algorithm has the higher time efficiency and system robustness. The convergence of the proposed AD-ADMM algorithm is analyzed, and several cases are used to validate the performance of the OPC scheme.© 2017 Elsevier Inc. All rights reserved.

Sustainable Optimization of Drilling Parameters for AA2017/AlN Composite Materials: A Grey Relational Analysis Approach

Modern engineering materials have seen remarkable development. Because conventional materials can no longer meet the needs of modern applications, numerous composites are being employed as viable alternatives. Drilling is the most important production step for most uses, and the resulting holes are high-stress zones that must be handled carefully. Scientists and engineers have long been interested in the challenge of finding the best combination of drilling settings for cutting-edge composite materials. As part of this research, AA2017/AlN composites with matrices made of AA2017 aluminium alloy and reinforcements made of 5, 10, and 15 wt % AlN were produced using stir casting. By experimenting with different input parameters, we were able to utilise the L9 OA to determine the best machining arrangement for drilling materials. The investigation focused on critical drilling characteristics, including burr height (H), thrust force (T), and surface roughness (SR), with a keen emphasis on sustainability.By considering the burr height (H), thrust force (T) and surface roughness (SR) and this work used grey relational analysis (GRA) to establish the optimum cutting parameters for drilling holes in the cutting-edge composite AA2017/AlN. The significance of different machining settings and their effect on the typical characteristics of the drilling were analysed using GRA. However, a confirmation experiment was conducted to ensure the highest quality outcomes. Test results and GRA indicate that the best grey relational grade is achieved with the following parameters: spindle speed (S) of 3500 rpm, feed rate (F) of 60 m/s, drill material (D) of Tungsten Carbide, and reinforcement (R) of 10%.. Analysis of variance (ANOVA) revealed statistically significant impacts on GRG from the drill material (29.08%), the feed rate (24.24%), and the spindle speed (19.52%). The error term was a function of the reinforcement percent and its interactions with all other parameters; however, the influence of the interaction between feed rate and drill material on GRG was small. The GRG is 0.856, which is higher than the prediction of 0.824. The calculated and measured values agree quite well and 3.7% is a negligible margin of error. The mathematical models for all reactions depending on the drill bits employed was also constructed.

Finite element analysis of drilling-induced damage responses on FRP hybrid bio/composite laminates

Machining/drilling is crucial in the joining process of composites. However, drilling composite materials often leads to hole dimensional inaccuracy, surface roughness and delamination, among others. These drilling-induced damage (DID) responses are associated with torque and thrust (principal drilling forces), and rampant in fibre-reinforced polymeric (FRP) hybrid bio/composite laminates. Therefore, a three-dimensional (3D) numerical approach, using finite element method (FEM) was undertaken to analyse the DID responses of FRP hybrid bio/composite laminates. Drilling simulation was performed at spindle velocity and feed rate of 3000 rpm and 5 mm/s, respectively. Both thrust force and torque were produced, computed and interpreted. From the results obtained, it was evident that drilling of synthetic (glass, G and carbon, C) FRP hybrid composites demanded higher or substantial torque and thrust forces, due to their superior strengths, exemplified by the (2G+2F)13 samples, when compared with the weaker natural/plant (flax, F; jute, J and hemp, H) FRP hybrid bio/composites, especially (J+F)27 samples. In addition, the investigation established the advantages of dual layup methods over single arrangements. Carbon and glass FRP hybrid composites exhibited excellent hybridisation properties, but their brittleness necessitated careful management of torque and thrust forces to prevent high DID responses. Summarily, this investigation provided a guide for FRP hybrid bio/composites design and drilling, in addition to opportunities for additional research on other process parameters towards further study.

Regression model-based parametric analysis of drilling of multi-walled carbon nanotubes-added glass fiber composite laminates

Multi-walled carbon nanotubes (MCNTs)-enhanced glass fiber composite (GFC) laminates are among the most promising materials for fulfilling various structural and non-structural requirements. They have also shown exceptional functional applications as excellent electrical and thermal conductors, as well as electromagnetic interference shielding materials. The present work primarily focuses on developing regression models for the drilling process of 0.3 wt% MCNTs-GFC laminates. For experimentation, three different coated drills—carbide, TiCN-coated, and TiAlN-coated—are used under both dry and chilled air cutting environments. The lowest thrust force, torque, and delamination factor were observed at a feed rate of 10 mm min−1 and a speed of 1500 RPM using a TiCN-coated drill in a chilled air environment. Regression analysis reveals that feed rate significantly influences thrust force, as justified by the R2 value, which is above 90% for the selected cutting conditions. The corresponding t and F statistics values indicate the statistical significance of the relevant explanatory factors. The efficiency of the developed models is further validated by considering the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) values, which are 136.9 and 144.7, respectively. These values indicate a good regression fit and likelihood of the models for data prediction. Additionally, there is a strong correlation (coefficient > 0.85) between thrust force and delamination factor under the selected cutting environments. Concurrently, the developed regression models are simulated and evaluated for random experiments (Nos. 87, 125, 187, 243, 244, and 399), and the predicted responses closely match the experimental values.

Effect of cutting speed on the surface integrity of single point diamond turned (100)Ge

The surface integrity of single crystal (100)Ge machined by on-axis single point diamond turning was investigated. The specimen was machined with a -25◦ rake angle single crystal diamond tool, with a depth of cut of 10 μm and a feedrate of 4 μm/rev. Six circular bands were machined on the specimen at different cutting speeds, ranging from 0.2 m/s to 10 m/s, while keeping all other machining and geometrical parameters constant. The surface topography was measured by atomic force microscopy and the near surface lattice disorder was investigated by Raman spectroscopy. The cutting and thrust forces were measured during machining, and their frequency domain was analyzed. Machining resulted in four lobes with four-fold symmetry, with differing amounts of surface fracture at each cutting speed. It was found that increasing the cutting speed generates surfaces with less or no brittle fracture for all cutting directions, causing some lobes to be undistinguishable. As the speed increased, the cutting and thrust force decreased monotonically. The frequency content of the force changed accordingly with the appearance of the surface, with a shift from 8 oscillations per revolution to 4 oscillations per revolution.

СТАБИЛИЗАЦИЯ ТЯГОВЫХ КАЧЕСТВ ТЕПЛОВОЗОВ МАГНИТНЫМИ УСИЛИТЕЛЯМИ СЦЕПЛЕНИЯ КОЛЁС С РЕЛЬСАМИ

This article defines the modes of operation of magnetic amplifiers to increase the coupling of wheels of shunting locomotives with rails at low speeds. The power consumption and the increase in the thrust force were determined, as well as the corresponding calculations were made and graphical dependencies were constructed.

Sample-Observed Soft Actor-Critic Learning for Path Following of a Biomimetic Underwater Vehicle

This paper addresses a learning-based path following control scheme for a biomimetic underwater vehicle (BUV) driven by undulatory fins. A dynamic line-of-sight (DLOS) guidance system is designed, which uses a virtual ball with a dynamic radius to detect the reference path. This DLOS system guides our BUV in the path following control and extracts essential information for the Markov decision process (MDP) of the control task. A deep reinforcement learning (DRL) algorithm, sample-observed soft actor-critic (SOSAC) is proposed. The can train out control policy with greater cumulative reward and higher success rate by using two tricks: sample observation and sample diversification. Based on the DLOS system, the MDP of the control task, and a multilayer perceptron (MLP) trained by the SOSAC, our control scheme is established. Experiments show that our BUV can successfully achieve path following control in an indoor pool environment by using this control scheme. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —The motivation of this paper is to design a practical end-to-end path following control scheme for the BUV driven by undulatory fins, and verify this scheme in a real-world environment. Unlike common autonomous underwater vehicles (AUVs) using axial propellers, the BUVs apply biomimetic propellers such as the undulatory fin. Multimodel wave patterns can be implemented by the undulatory fin, which generates nonlinear thrust and lateral force simultaneously. This propulsive feature makes the driving force on different directions of the BUV to be strong coupled, and it is complicated to convert the outputs of a common controller into waveform parameters of the undulatory fins to control the BUV. Therefore, in this paper, we proposed an end-to-end learning-based path following controller, which observes environmental information and directly generates waveform parameters to control our BUV. Experiments suggest that our control scheme is practical and valid.

Interactional aerodynamics and acoustics of a rotor with an airframe in hover

The demand for the development of urban air mobility (UAM) powered by electric systems has been steadily rising across private and public sectors. Most UAM flights incorporate a distributed electric propulsion system to enhance aircraft safety and reliability, which entails an increase in the number of rotors or propellers. Consequently, aerodynamics and aeroacoustics are significantly influenced by strong interactions between the rotor and the airframe. In this study, we conducted a computational investigation to examine the impact of rotor–airframe interaction on aerodynamic and aeroacoustic characteristics. This examination considered variations in airframe shape and the distance between the rotor and airframe. The aerodynamic analysis was executed using the lattice-Boltzmann method simulation, in which acoustic predictions were made using the Ffowcs Williams–Hawkings(FW–H) acoustic analogy with a permeable surface. The airframe consists of two geometries: a cylinder and a cone. Tip vortex breakdown and the transition into the turbulent wake state were captured in both airframes, and a fountain flow was affected by the downwash circulation generated under certain proximity of airframe cases. The acoustic prediction results showed that high-intensity noise radiated over the broad surface of the airframe in the conical airframe case. Significant thrust force fluctuations and an increase in noise level were observed at the smallest rotor tip clearance, S/R=−0.1, compared to the isolated rotor. Furthermore, the noise contribution of the rotor and airframe was compared, revealing that the airframe noise level was even higher than the rotor noise at S/R=−0.1.

Force coefficient characterization in machining of UD-CFRP using numerical-analytical approach

A numerical-analytical approach was utilized to construct a predictive model of cutting force for machining unidirectional carbon fiber reinforced polymer (UD-CFRP) laminates. The force coefficients in the model, which include friction angle, shear plane angle, shear strength, and rebound height, can be characterized by the fiber orientations ranging from 0° to 180°. The accuracy of the model was confirmed through experimental verification. The results indicate good agreement between the predicted and experimental values, with relative errors below 14.8%, except for the thrust force at 90°. Additionally, the study examined the influence of rake angle and flank angle on the cutting force, revealing two critical points in the predicted cutting force curve throughout the fiber orientation. These turning points shifted with changes in the rake angle. For instance, the value of the first critical point changes from 60° to 45° when the rake angle range shifts from [0°, 5°] to [10°, 15°]. This indicates that a larger rake angle facilitated an earlier transformation of chip formation mode, leading to a decrease in cutting force. Furthermore, the cutting force decreased as the rake angle increased between the two turning points. The impact of the flank angle on the cutting force was determined to be minimal, and the turning points’ positions remained consistent as the flank angle increased.

Numerička analiza udarnog voza u konusnim mlaznicama sa ravnim grlom

The overexpanded flow regime in supersonic rocket engine nozzles presents different shock wave structures due to the geometrical configurations of the internal walls. In the present investigation, the study of the shock train phenomenon is addressed for a group of convergentdivergent conical nozzles with straight-cut throats for the overexpanded flow condition for NPR=12. The viscous and compressible flow field under stationary conditions is simulated with the RANS model in the ANSYSFluent R16.2 code, which applies the finite volume method (FVM) to discretize the computational domain. The Spalart-Allmaras turbulence model is used, and Sutherland's law is used for the viscosity as a function of temperature. The results show that, in the straight-cut throat section, as its length increases, the flow accelerates and decelerates with the presence of oblique shocks, which forms a definite shock train structure, where the flow velocity fluctuations are within the estimated Mach number range of 0.6 to 1.8. Increasing the throat length significantly affects the flow development at the nozzle outlet, which decreases the thrust force.

Research progress on the catalytic and thermal decomposition of ammonium dinitramide (ADN).

Ammonium dinitramide (NH4N(NO3)2, ADN) is regarded as a promising oxidizer due to its low signature and high specific impulse. Generally, ADN undergoes exothermic decomposition above 140 °C accompanied by the byproduct of ammonium nitrate (AN). The inevitable endothermic decomposition of AN decreases the overall heat release, and so there is a need to develop efficient catalysts to guide ADN decomposition along desired pathways with a lower decomposition temperature and higher heat release. A suitable catalyst should be able to withstand the harsh conditions in a thruster to achieve a stable thrust force, which poses a huge obstacle for manufacturing a stable and active catalyst. This review gives a comprehensive summary of the thermal and catalytic decomposition pathways of ADN for the first time, which is expected to deepen the understanding of its reaction mechanism and provide useful guidance for designing prospective catalysts toward efficient ADN decomposition.

Research on High Thrust Force Characteristics with Proper Fractional-Slot Concentrated Winding for A Ultra-Low Speed Tubular PM Linear Machine

Research on High Thrust Force Characteristics with Proper Fractional-Slot Concentrated Winding for A Ultra-Low Speed Tubular PM Linear Machine