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Theory of Electromagnetism and Gravity —Modeling Earth as a Rotating Solenoid Coil
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作者 Greg Poole 《Journal of High Energy Physics, Gravitation and Cosmology》 2017年第4期663-692,共30页
Presented in this manuscript are conventional electrical engineering tools to model the earth as a rotating electrical machine. Calculations using known parameters of the earth and measured field data has resulted in ... Presented in this manuscript are conventional electrical engineering tools to model the earth as a rotating electrical machine. Calculations using known parameters of the earth and measured field data has resulted in new understanding of the earth’s electrical system and gyroscopic rotation. The material makeup of the inner earth is better understood based on derived permeability and permittivity constants. The planet has been modeled as simple coils and then as a parallel impedance circuit which has led to fundamental insight into planetary speed control and RLC combination for Schumann Resonance of 7.83 Hz. Torque and Voltage Constants and the inverse Speed Constant are calculated using three methods and all compare favorably with Newton’s Gravitational Constant. A helical resonator is referenced and Schumann’s Resonant ideal frequency is calculated and compared with others idealism. A new theory of gravity based on particle velocity selector at the poles is postulated. Two equations are presented as the needed links between Faraday’s electromagnetism and Newtonian physics. Acceleration and Deceleration of earth is explained as a centripetal governor. A new equation for planetary attraction and the attraction of atomic matter is theorized. Rotation of the earth’s electrical coil is explained in terms of the Richardson effect. Electric power transfer from the sun to the planets is proposed via Flux Transfer Events. The impact of this evolving science of electromagnetic modeling of planets will be magnified as the theory is proven, and found to be useful for future generations of engineers and scientists who seek to discover our world and other planets. 展开更多
关键词 Ampere Biot-Savart CENTRIPETAL Acceleration CENTRIPETAL GOVERNOR Dynamo EARTH Einstein-de Haas Effect Electric Field Electromagnetism Flux Transfer Events GOVERNOR Control GRAVITY Gravitational CONSTANT Helical Resonator Lenz Law Lorentz Lightning Magnetic Field Motor CONSTANT Parallel Impedance Planet SPEED Control Schumann Resonance Richardson Effect Solenoid SPEED CONSTANT Solar Power System torque CONSTANT Velocity Selector Voltage CONSTANT
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Comparative Study of Conventional, Fuzzy Logic and Neural PID Speed Controllers with Torque Ripple Minimization for an Axial Magnetic Flux Switched Reluctance Motor 被引量:1
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作者 Eric S. Sanches José A. Santisteban 《Engineering(科研)》 2014年第11期655-669,共15页
Three speed controllers for an axial magnetic flux switched reluctance motor with only one stator, are described and experimentally tested. As it is known, when current pulses are imposed in their windings, high rippl... Three speed controllers for an axial magnetic flux switched reluctance motor with only one stator, are described and experimentally tested. As it is known, when current pulses are imposed in their windings, high ripple torque is obtained. In order to reduce this ripple, a control strategy with modified current shapes is proposed. A workbench consisting of a machine prototype and the control system based on a microcontroller was built. These controllers were: a conventional PID, a fuzzy logic PID and a neural PID type. From experimental results, the effective reduction of the torque ripple was confirmed and the performance of the controllers was compared. 展开更多
关键词 AXIAL Flux SRM PID SPEED CONTROLLER FUZZY Logic PID SPEED CONTROLLER Neural PID SPEED CONTROLLER torque RIPPLE Minimization Current Shape Control Strategy
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飞轮储能系统在汽车中的应用研究 被引量:13
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作者 文少波 蒋书运 《机械设计与制造》 北大核心 2010年第12期82-84,共3页
随着世界能源危机和环境污染问题的日益严重,人们对汽车节能和减排的要求越来越高,采用储能飞轮进行汽车功率和能量的调节是一种有效的解决办法。近年来高强度的复合材料、低功耗磁轴承、先进的电力电子控制等一系列关键技术的发展,使... 随着世界能源危机和环境污染问题的日益严重,人们对汽车节能和减排的要求越来越高,采用储能飞轮进行汽车功率和能量的调节是一种有效的解决办法。近年来高强度的复合材料、低功耗磁轴承、先进的电力电子控制等一系列关键技术的发展,使得飞轮储能系统在汽车上的应用成为可能。详细介绍了飞轮储能系统的结构、原理和特点,总结了飞轮储能技术在汽车上的应用发展现状,指出了车用高速飞轮储能系统的应用存在的关键问题,为进一步研究提供参考。 展开更多
关键词 flywheel energy storage system study
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永磁偏置径向磁轴承在磁悬浮反作用飞轮系统中的应用 被引量:2
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作者 王顺 杨逢瑜 +5 位作者 陈君辉 王其磊 娄磊 Feng-yu Jun-hui Qi-lei 《机械设计与制造》 北大核心 2010年第12期68-70,共3页
针对现有径向磁轴承结构电励磁磁路耦合的缺陷,设计了一种新型径向永磁偏置混合磁轴承结构,介绍了这种轴承的结构特点和工作原理,并利用等效磁路法和有限元法(FEM)对该永磁偏置径向混合磁轴承进行了电磁分析,得出了磁轴承的数学模型和... 针对现有径向磁轴承结构电励磁磁路耦合的缺陷,设计了一种新型径向永磁偏置混合磁轴承结构,介绍了这种轴承的结构特点和工作原理,并利用等效磁路法和有限元法(FEM)对该永磁偏置径向混合磁轴承进行了电磁分析,得出了磁轴承的数学模型和主要参数的设计结果。研究结果表明:该径向永磁偏置磁轴承可以有效地避免磁路耦合现象,提高磁轴承系统的控制性能。 展开更多
关键词 radial magnetic bearing
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Torque teno virus in liver diseases: On the way towards unity of view 被引量:2
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作者 Vasiliy I Reshetnyak Igor V Maev +2 位作者 Alexandr I Burmistrov Igor A Chekmazov Tatiana I Karlovich 《World Journal of Gastroenterology》 SCIE CAS 2020年第15期1691-1707,共17页
The review presents the data accumulated for more than 20 years of research of torque teno virus(TTV).Its molecular genetic structure,immunobiology,epidemiology,diagnostic methods,possible replication sites,and pathog... The review presents the data accumulated for more than 20 years of research of torque teno virus(TTV).Its molecular genetic structure,immunobiology,epidemiology,diagnostic methods,possible replication sites,and pathogenicity factors are described.TTV is a virus that is frequently detectable in patients with different viral hepatitides,in cases of hepatitis without an obvious viral agent,as well as in a healthy population.There is evidence suggesting that biochemical and histological changes occur in liver tissue and bile duct epithelium in TTV monoinfection.There are sufficient histological signs of liver damage,which confirm that the virus can undergo a replicative cycle in hepatocytes.Along with this,cytological hybridization in TTV-infected cells has shown no substantial cytopathic(cell-damaging)effects that are characteristic of pathogenic hepatotropic viruses.Studying TTV has led to the evolution of views on its role in the development of human pathology.The first ideas about the hepatotropism of the virus were gradually reformed as new data became available on the prevalence of the virus and its co-infection with other viruses,including the viruses of the known types of hepatitides.The high prevalence of TTV in the human population indicates its persistence in the body as a virome and a nonpathogenic virus.It has recently been proposed that the level of TTV DNA in the blood of patients undergoing organ transplantation should be used as an endogenous marker of the body’s immune status.The available data show the polytropism of the virus and deny the fact that TTV can be assigned exclusively to hepatitis viruses.Fortunately,the rare detection of the damaging effect of TTV on hepatic and bile duct epithelial cells may be indirect evidence of its conditionally pathogenic properties.The ubiquity of the virus and the variability of its existence in humans cannot put an end to its study. 展开更多
关键词 torque teno VIRUS PREVALENCE of torque teno VIRUS torque teno VIRUS in liver disease Virome and torque teno VIRUS torque teno VIRUS and human IMMUNE status
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Semi-Automatic Modeling Technique of Torque Converter Flow Passage 被引量:3
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作者 Shiping Liu Shujuan Zheng 《Modern Mechanical Engineering》 2013年第2期59-68,共10页
The modeling technique of hydrodynamic torque converter flow passage was investigated. The semi-automatic modeling technique of torque converter flow passage was proposed. The flow passage model of each converter whee... The modeling technique of hydrodynamic torque converter flow passage was investigated. The semi-automatic modeling technique of torque converter flow passage was proposed. The flow passage model of each converter wheel is considered as a revolution entity sliced by two curved surfaces. In order to generate the revolution entity, a new approximation method, condition optimum arc approximation, was proposed. The method was used to approximate the meridional streamlines of the inner and outer wall. As a result, the three-dimensional revolution entity can be conveniently generated. In order to create slice surfaces, the central stream surface of flow passage was approximated with a quadric surface. The normal vector of the quadric surface and the thickness/thickness-function of bade were used to calculate the discrete point coordinates of blade surfaces. Via the rotation transformation to the coordinates, the discrete point coordinates of slice surfaces were obtained. A parameterized program code used for the hydrodynamic torque converter design and semi-automatic modeling was developed. Modeling errors were calculated and analyzed. The flow passage model was generated in several minutes with the help of the program code, Auto CAD and Solidworks software. Finally, the model was inputted into Gambit, and the pre-processing task used for the numerical simulation of torque converter flow field was successfully completed. The investigation results show that the semi-automatic modeling not only can ensure the accuracy of modeling, but also librates the research and design workers of torque converter from the time-consuming modeling work, which paves the way for the numerical simulation of the complex flow field of the hydrodynamic torque converter. 展开更多
关键词 HYDRODYNAMIC torque Converter Flow Field Simulation SEMI-AUTOMATIC Modeling QUADRIC Surface Condition OPTIMUM APPROXIMATION
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串联磁路结构双定子混合式直接驱动电动机的定位转矩分析及抑制策略 被引量:9
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作者 寇宝泉 张千帆 +1 位作者 程树康 裴宇龙 《中国电机工程学报》 EI CSCD 北大核心 2005年第8期145-150,共6页
文中提出一种抑制串联磁路结构双定子混合式直接驱动电动机(Double-Stator Hybrid Direct Drive Motor,以下简称DSHBDDM)定位转矩的方案。利用串联磁路结构DSHBDDM 的简化磁网络模型,定量分析了该电机的定位转矩特性, 提出了内、外定子... 文中提出一种抑制串联磁路结构双定子混合式直接驱动电动机(Double-Stator Hybrid Direct Drive Motor,以下简称DSHBDDM)定位转矩的方案。利用串联磁路结构DSHBDDM 的简化磁网络模型,定量分析了该电机的定位转矩特性, 提出了内、外定子错齿削弱定位转矩的方案,分析了内、外定子错齿对串联磁路结构DSHBDDM 电磁转矩的影响,提出了错齿系数的概念。并对样机进行了实验测试,实验结果表明,电机内、外定子错齿,在有效削弱定位转矩、减小电磁转矩中的波动分量的同时,对电磁转矩的恒定分量即有用分量的影响却很小。实验结果与理论解析的趋势是一致的,验证了理论分析的正确性。 展开更多
关键词 Hybrid Direct Drive 齿
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异步电机直接转矩控制算法的DSP实现 被引量:1
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作者 魏欣 陈大跃 赵春宇 《工业控制计算机》 2005年第4期64-65,共2页
直接转矩控制是一种新型的交流电机变频驱动控制方法。本文详细介绍了异步电机直接转矩控制算法在TM S320F240D SP控制器上的实现方法。TM S320F240D SP芯片丰富的片内外设资源给编程带来了极大方便。程序能够基于直接转矩控制算法高效... 直接转矩控制是一种新型的交流电机变频驱动控制方法。本文详细介绍了异步电机直接转矩控制算法在TM S320F240D SP控制器上的实现方法。TM S320F240D SP芯片丰富的片内外设资源给编程带来了极大方便。程序能够基于直接转矩控制算法高效地控制电机运行。并且,实现了D SP程序与PC上位机的RS-232串口通信。在PC上可以通过串口向D SP发送命令、设置参数。本文设计的程序对直接转矩控制算法及其改进算法的研究有积极意义。 展开更多
关键词 DSP TMS320F240 DSP RS-232 DSP PC
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Change monitoring of earth rotation parameter with Maglev gyroscope precessional torque
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作者 YANG Zhi-qiang, GONG Yun, SHI Zhen, LI Yun Geological Engineering and Geomatics Institute, Chang’an University, Xi’an 710054, China 《中国有色金属学会会刊:英文版》 CSCD 2011年第S3期589-593,共5页
Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyrosc... Through analyzing the relationship between gyro dynamic torques produced by the changes of earth rotation parameters (ERP), a method of measuring the earth rotation parameters was proposed and explored by using gyroscope. The preliminary experiments were carried out using GAT Maglev Gyro Station (which is self-developed by China). Considering the measurement and expanding-application of the earth rotation parameters, some ideas and opinions about the structure design, measurement methods and data processing of gyro were proposed, and some outlook of the expanding-application of the gyroscope in geodetic and geophysical fields were done. The experimental results show that using the high-precision gyroscope to determine the changes of ERP is feasible, with the emergence of ultra-high precision gyro; it is possible for determining the earth rotation parameters by gyro in stead of by current complex space surveying technology. 展开更多
关键词 MAGLEV GYROSCOPE earth ROTATION parameters (ERP) precessional torque POLE motion length of DAY
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Reducing Fuel Consumption Using Flywheel Battery Technology for Rubber Tyred Gantry Cranes in Container Terminals 被引量:2
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作者 Kai Hou Tan Yap Fook Fah 《Journal of Power and Energy Engineering》 2017年第7期15-33,共19页
Flywheel Energy Storage System (FESS) is used as an energy regeneration system to help with reducing peak power requirements on RTG cranes that are used to load or unload container ships. Nevertheless, with the use of... Flywheel Energy Storage System (FESS) is used as an energy regeneration system to help with reducing peak power requirements on RTG cranes that are used to load or unload container ships. Nevertheless, with the use of FESS, Port Operator can deploy undersized generator for new RTG as this will further reduce fuel consumption. This paper presents the investigation of the amount of energy and fuel consumption that can be reduced in Rubber Tyred Gantry (RTG) cranes in container terminals by the use of simulation. In addition, Variable Speed Generator is integrated to the simulation-hybridized RTG. Simulation results reveal that the total energy saving exceeded 30% relatively to conventional RTG. A hardware-in-loop system is introduced for the purpose of validating the simulation results. The hardware components procured include a FESS, a Variable Frequency Drive (VFD) and brake resistors. 展开更多
关键词 flywheel Energy Storage System RUBBER Tyred GANTRY Mechanical BATTERY HARDWARE-IN-LOOP (HIL) Simulation
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Repairing of RC T-Section Beams with Opening by CFRP for Cracks and Ultimate Torque
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作者 Ali Sabah Al Amli Nadhir Al-Ansari Sabah Jasim Dahboosh Shejiri 《Journal of Civil Engineering and Architecture》 2018年第2期83-90,共8页
The repair of reinforced concrete(RC)beams with carbon fiber reinforced polymers(CFRP)is experimentally investigated in this study.The four T-section reinforced reactive powder concrete beams with many locations of ci... The repair of reinforced concrete(RC)beams with carbon fiber reinforced polymers(CFRP)is experimentally investigated in this study.The four T-section reinforced reactive powder concrete beams with many locations of circular opening were repaired by CFRP and investigated under pure torsion.The repairing beams were tested to obtain the effect of the amount of CFRP laminate on beams cracking and ultimate torque behavior,angle of twist and failure modes.The results obtained from the adopted repairing technique showed a significant effect of external high strength CFRP laminates on effectively restore of section solid of 85%of crack torsional strength effectively restored.In addition,the results show that effectively restoring of section opening by 82%-80%of crack torsional strength,and the adopted repairing technique gives a good strength to the beams. 展开更多
关键词 torque first and ULTIMATE cracks RPC OPENING T-section repairing carbon fiber reinforced polymer(CFRP)
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Generation and Analysis of Hybrid-Electric Vehicle Transmission Shift Schedules with a Torque Split Algorithm 被引量:1
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作者 Nicholas J. Connelly Derek I. George +1 位作者 Andrew C. Nix W. Scott Wayne 《Journal of Transportation Technologies》 2020年第1期21-49,共29页
The increased concern over global climate change and lack of long-term sustainability of fossil fuels in the projected future has prompted further research into advanced alternative fuel vehicles to reduce vehicle emi... The increased concern over global climate change and lack of long-term sustainability of fossil fuels in the projected future has prompted further research into advanced alternative fuel vehicles to reduce vehicle emissions and fuel consumption. One of the primary advanced vehicle research areas involves electrification and hybridization of vehicles. As hybrid-electric vehicle technology has advanced, so has the need for more innovative control schemes for hybrid vehicles, including the development and optimization of hybrid powertrain transmission shift schedules. The hybrid shift schedule works in tandem with a cost function-based torque split algorithm that dynamically determines the optimal torque command for the electric motor and engine. The focus of this work is to develop and analyze the benefits and limitations of two different shift schedules for a position-3 (P3) parallel hybrid-electric vehicle. a traditional two-parameter shift schedule that operates as a function of vehicle accelerator position and vehicle speed (state of charge (SOC) independent shift schedule), and a three-parameter shift schedule that also adapts to fluctuations in the state of charge of the high voltage batteries (SOC dependent shift schedule). The shift schedules were generated using an exhaustive search coupled with a fitness function to evaluate all possible vehicle operating points. The generated shift schedules were then tested in the software-in-the-loop (SIL) environment and the vehicle-in-the-loop (VIL) environment and compared to each other, as well as to the stock 8L45 8-speed transmission shift schedule. The results show that both generated shift schedules improved upon the stock transmission shift schedule used in the hybrid powertrain comparing component efficiency, vehicle efficiency, engine fuel economy, and vehicle fuel economy. 展开更多
关键词 Hybrid-Electric Vehicles torque SPLIT ALGORITHM SHIFT SCHEDULE SHIFT Map COST Function SOC Dependent
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Fuzzy Torque Control of the Bionic Flexible Manipulator Actuated by Pneumatic Muscle Actuators 被引量:5
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作者 Kai Liu Yining Chen +3 位作者 Jiaqi Xu Yang Wu Yonghua Lu Dongbiao Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第5期80-94,共15页
A bionic flexible manipulator driven by pneumatic muscle actuator(PMA)can better reflect the flexibility of the mechanism.Current research on PMA mainly focuses on the modeling and control strategy of the pneumatic ma... A bionic flexible manipulator driven by pneumatic muscle actuator(PMA)can better reflect the flexibility of the mechanism.Current research on PMA mainly focuses on the modeling and control strategy of the pneumatic manipulator system.Compared with traditional electro-hydraulic actuators,the structure of PMA is simple but possesses strong nonlinearity and flexibility,which leads to the difficulty in improving the control accuracy.In this paper,the configuration design of a bionic flexible manipulator is performed by human physiological map,the kinematic model of the mechanism is established,and the dynamics is analyzed by Lagrange method.A fuzzy torque control algorithm is designed based on the computed torque method,where the fuzzy control theory is applied.The hardware experimental system is established.Through the co-simulation contrast test on MATLAB and ADAMS,it is found that the fuzzy torque control algorithm has better tracking performance and higher tracking accuracy than the computed torque method,and is applied to the entity control test.The experimental results show that the fuzzy torque algorithm can better control the trajectory tracking movement of the bionic flexible manipulator.This research proposes a fuzzy torque control algorithm which can compensate the error more effectively,and possesses the preferred trajectory tracking performance. 展开更多
关键词 PNEUMATIC MUSCLE actuator BIONIC flexible manipulator COMPUTED torque method FUZZY torque control
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Analysis of Torque Ripple of Permanent Magnet Brushless DC Motor
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作者 张志忠 孙力 陆永平 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1997年第2期89-94,共6页
Torque tripple has significant effect on performance of permanent magnet brushless DC motor. This paper presents a mathematical model built for such a motor, the analysis of torque tripple for a brushless DC motor wit... Torque tripple has significant effect on performance of permanent magnet brushless DC motor. This paper presents a mathematical model built for such a motor, the analysis of torque tripple for a brushless DC motor with sinusoidal flux distribution, which is verified by torque tripple experiments run with a test motor, and equations developed for torque tripple resulting from different sator current errors. 展开更多
关键词 PERMANENT MAGNET BRUSHLESS DC MOTOR torque RIPPLE Park transfer sinusoidal flux distribution
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Torque Control Algorithm and Its Simulation of Capturing a Moving Target for Free Flying Space Robots
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作者 李华忠 《High Technology Letters》 EI CAS 1999年第1期54-60,共7页
Torque control algorithm and its simulation of capturing a moving target for Free Flying Space Robots(FFSR) are discussed in this paper. The efficient recursive algorithm of joint driven torque for FFSR is developed. ... Torque control algorithm and its simulation of capturing a moving target for Free Flying Space Robots(FFSR) are discussed in this paper. The efficient recursive algorithm of joint driven torque for FFSR is developed. The torque control algorithm combined with Resolved Motion Rate Contro(RMRC) based on Generalized Jacobian Matrix(GJM) for capturing a moving target is proposed. The computer simulation verifies the effectiveness of the proposed algorithm. 展开更多
关键词 Free FLYING SPACE ROBOTS Joint driving torque Generalized JACOBIAN matrix Computer SIMULATION
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Assessment of Cutting Parameters Influencing on Thrust Force and Torque during Drilling Particulate Filled Glass Fabric Reinforced Epoxy Composites
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作者 Bhadrabasol Revappa Raju Bheemappa Suresha +1 位作者 Ragera Parameshwarappa Swamy Bannangadi Swamy Gowda Kanthraju 《Journal of Minerals and Materials Characterization and Engineering》 2013年第3期101-109,共9页
Drilling is indispensable process and it cannot be avoided for joining composite structures used in various engineering applications. In this research article, the influence of drilling parameters on thrust force and ... Drilling is indispensable process and it cannot be avoided for joining composite structures used in various engineering applications. In this research article, the influence of drilling parameters on thrust force and torque of silica (SiO2) and alumina (Al2O3) filled into glass fabric reinforced epoxy (G-E) composites are analyzed. Drilling experiments are conducted on these composite materials using BATLIBOI make radial drilling machine. Two different drill bits (HSS and cemented carbide) are used for the experimentation. The influence of drilling parameters like cutting speed and feed on thrust force and torque on drilling of particulate filled G-E composites has been carried out. The experimental results indicated that the thrust force and torque were increased with increasing feed and cutting speed for all the composites tested. Further, it is observed that the carbide drill performed better than HSS drill during drilling of particulate filled G-E composites. The drilled surfaces are examined using scanning electron microscopy (SEM) and damage mechanisms are discussed. 展开更多
关键词 PARTICULATE FILLED Glass-Epoxy Composites DRILLING THRUST Force and torque HSS and CARBIDE Drills
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基于感应电机启动电磁转矩Hilbert-Huang变换的转子断条故障诊断 被引量:43
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作者 牛发亮 黄进 +2 位作者 杨家强 陈理渊 金海 《中国电机工程学报》 EI CSCD 北大核心 2005年第11期107-112,共6页
该文提出了一种感应电机转子故障诊断新方法。当感应电机转子出现断条故障时,转子绕组的不对称将会使电磁转矩谱中引入2sfs(s为转差率,fs为电网频率)谐波分量。利用Hilbert-Huang变换中经验模态分解(EMD)方法对启动电磁转矩信号进行了分... 该文提出了一种感应电机转子故障诊断新方法。当感应电机转子出现断条故障时,转子绕组的不对称将会使电磁转矩谱中引入2sfs(s为转差率,fs为电网频率)谐波分量。利用Hilbert-Huang变换中经验模态分解(EMD)方法对启动电磁转矩信号进行了分解,得到若干本征模态函数(IMF)。通过计算包含故障信息的IMF分量的瞬时频率,可以检测出转子断条故障。同时,根据包含故障信息的IMF的幅值可以进一步判断出转子断条根数。实验结果证明该方法是可行的。 展开更多
关键词 HILBERT-HUANG (EMD) IMF
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Torque and bending moment acting on a flexible shaft agitated by disk turbines in a gas–liquid stirred vessel
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作者 Yangyang Liang Zhengming Gao +3 位作者 Dai'en Shi Haotian Li Yuyun Bao Ziqi Cai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第4期781-793,共13页
The torque and bending moment acting on a flexible overhung shaft in a gas–liquid stirred vessel agitated by a Rushton turbine and three different curved-blade disk turbines(half circular blades disk turbine, half el... The torque and bending moment acting on a flexible overhung shaft in a gas–liquid stirred vessel agitated by a Rushton turbine and three different curved-blade disk turbines(half circular blades disk turbine, half elliptical blades disk turbine, and parabolic blades disk turbine) were experimentally measured by a customized moment sensor. The results show that the amplitude distribution of torque can be fitted by a symmetric bimodal distribution for disk turbines, and generally the distribution is more dispersive as the blade curvature or the gas flow rate increases. The amplitude distribution of shaft bending moment can be fitted by an asymmetric Weibull distribution for disk turbines. The relative shaft bending moment manifests a "rising-falling-rising" trend over the gas flow number, which is a corporate contribution of the unstable gas–liquid flow around the impeller, the gas cavities behind the blades, and the direct impact of gas on the impeller. And the "falling" stage is greater and lasts wider over the gas flow number for Rushton turbine than for the curved-blade disk turbines. 展开更多
关键词 SHAFT bending moment torque DISK turbines Gasliquid flow Fluid structure interaction
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Detection of the Critical Duration of Different Types of Voltage Sags for Synchronous Machine Torque Oscillation
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作者 Jaber Alipoor Aref Doroudi Morteza Ghaseminezhad 《Energy and Power Engineering》 2012年第3期117-124,共8页
Voltage sages are classified in seven types that in each type, the voltage amplitude and angle of phase voltages are different. We demonstrated that voltage sag types have different effects on synchronous motor, espec... Voltage sages are classified in seven types that in each type, the voltage amplitude and angle of phase voltages are different. We demonstrated that voltage sag types have different effects on synchronous motor, especially on its torque pulsations. Torque pulsations are different in shape of oscillations and moreover, peak torque when voltage magnitude is restored has different correlation with sag duration, as sag type varies. By flux trajectory analysis, we mathematically extracted the critical durations for different types of voltage sags, in the case that the sag begins at the zero angle of the voltage wave. In order to observe the validity of the results, we simulated a synchronous motor subjected to different types of voltage sags. The simulation results confirmed the claim. 展开更多
关键词 Flux TRAJECTORY Analysis Power Quality SYNCHRONOUS Motor torque PULSATIONS Voltage SAG
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Microstructure and properties of 35 kg large aluminum alloy flywheel housing components formed by squeeze casting with local pressure compensation
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作者 Ju-fu Jiang Jing Yan +4 位作者 Ying-ze Liu Ning Ge Ying Wang Chang-jie Ding De-chao Zou 《China Foundry》 SCIE EI CAS CSCD 2024年第5期563-576,共14页
The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 kg.The numerical simulation,microstructure observation and phase characterization were ... The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 kg.The numerical simulation,microstructure observation and phase characterization were performed,and the influence of local pressure compensation on feeding of thick-wall position,microstructure and mechanical properties of the formed components were discussed.Results show that the molten metal keeps a good fluidity and the filling is complete during the filling process.Although the solidification at thick-wall positions of the mounting ports is slow,the local pressure compensation effectively realizes the local forced feeding,significantly eliminating the shrinkage cavity defects.In the microstructure of AlSi9Mg alloy,α-Al primarily consists of fragmented dendrites and rosette grains,while eutectic Si predominantly comprises needles and short rods.The impact of local pressure compensation on strength is relatively minimal,yet its influence on elongation is considerable.Following local pressure compensation,the average elongation at the compensated areas is 9.18%,which represents a 44.90%higher than that before compensation.The average tensile strength is 209.1 MPa,and the average yield strength is 100.6 MPa.The local pressure compensation can significantly reduce or even eliminate the internal defects in the 35 kg large-weight components formed by squeeze casting. 展开更多
关键词 squeeze casting local pressure compensation aluminum alloy microstructure mechanical properties large flywheel housing components
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