• Title/Summary/Keyword: Thrust density

Search Result 133, Processing Time 0.027 seconds

Shape Design of Slotless Type PMLSM for Improving Thrust Density (Slotless 영구자석형 선형 동기전동기의 고추력화를 위한 형상 설계)

  • 김용철;김규탁
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.52 no.7
    • /
    • pp.320-326
    • /
    • 2003
  • Slotless Permanent Magnet Linear Synchronous Motor (PMLSM) has good control ability but thrust density is low. So, this paper proposes inserted core type of slotless PMLSM to improve its thrust density. Inserting the core between windings of each phase, detent force is generated by the difference of magnetic resistance in an air gap. To minimize detent force, this paper applies the neural network to inserted core type of slotless PMLSM. The, Magnetic pole ratio, the width of the inserted core and the width of the coil are selected as a design parameter to minimize detent force. In comparison with inserted core type one, thrust ripple greatly decreases by minimizing detent force and also thrust increases in this optimal model.

Analysis and Optimization of Air-Core Permanent Magnet Linear Synchronous Motors with Overlapping Concentrated Windings for Ultra-precision Applications

  • Li, Liyi;Tang, Yongbin;Ma, Mingna;Pan, Donghua
    • Journal of international Conference on Electrical Machines and Systems
    • /
    • v.2 no.1
    • /
    • pp.16-22
    • /
    • 2013
  • This paper presents the analysis and optimization of air-core permanent magnet linear synchronous motor with overlapping concentrated windings to achieve high thrust density, high thrust per copper losses and low thrust ripple. For the motor design, we adopt equivalent magnetizing current (EMC) method to analyze the magnetic field and give analytical formulae for calculation of motor parameters such as no-load back EMF, dynamic force, thrust density and thrust per copper losses. Further, we proposed a multi-objective optimization by genetic algorithm to search for the optimum parameters. The design optimization is verified by 2-D Finite Element analysis (FEA).

Optimal Design of Extremely Small Thrust VCM for Nanoindenter (나노 인덴터용 미소 추력 보이스코일 모터의 최적 설계)

  • 조주희;이진우;이철규;권병일
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.53 no.2
    • /
    • pp.69-75
    • /
    • 2004
  • In this paper, we propose the shape of extremely small thrust VCM for application of the Nanoindenter, which enables control of very small force and displacement. We performed optimization of the VCM shape using conjugated gradient method. And the purposes of optimization are the minimization of the permanent magnet size for the efficient systems, minimization of deviation of flux density from the air gap for operate on regular thrust and a linearization of thrust for a good control characteristic. The finite element method is used for characteristic analysis. The node moving method is used to redundant changes of design variables. As a result, the VCM produces a yew small force by the difference of flux density of lower part from higher one. Also, in a wide range of current (0[A]-1[A]), the VCM produces linear driving thrust by saturating the magnetic circuit path and operate on regular thrust by minimizing deviation of flux density of the air gap.

Plume Density Simulation of KM Residual Thrust Using DSMC Method (DSMC 방법을 이용한 킥모터 잔류추력 Plume Density 시뮬레이션)

  • Choi, Young-In;Kim, Keun-Taek
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.18 no.6
    • /
    • pp.27-33
    • /
    • 2014
  • 2nd stage of KSLV-I, NaRo-Ho, performs CCAM not to collide with Naro Science Satellite. At that moment, the satellite should pass through the Plume Density area which was generated by KSLV-I KM residual thrust. Therefore, it is necessary to predict Plume Density field of KM residual thrust and guarantee the safety of the trajectory of payload. In this paper, DSMC method was used to simulate Plume Density by KM residual thrust and the simulation showed that the trajectory of Naro Science Satellite was safe.

A Study on the Thrust Throttling Using Gas Injection in Swirl Injectors (기체주입을 이용한 와류형 분사기들에서의 가변추력 연구)

  • Lee, Wongu;Yoon, Youngbin;Ahn, Kyubok
    • Journal of ILASS-Korea
    • /
    • v.23 no.4
    • /
    • pp.159-168
    • /
    • 2018
  • Thrust throttling in a liquid rocket engine can be implemented via several ways such as high pressure drop injector, dual manifold, multiple chamber, pintle injector, and gas injection. Thrust throttling using gas injection controls thrust by usually injecting inert gas into propellant through an aerator to reduce the propellant's bulk density. In this study, the outside-in aerator was used in the propellant line to create two phase flow. Closed-type, open-type, and screw-type bi-swirl coaxial injectors were utilized for investigating throttling characteristics such as pressure drop, mixture density, and discharge coefficient according to gas-liquid mass ratio.

Simulation of KM Plume Density Field by Residual Thrust Using DSMC Method (DSMC 방법을 사용한 KM 잔류추력 밀도장 시뮬레이션)

  • Choi, Young-In;Ok, Ho-Nam;Hong, Il-Hee
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.769-771
    • /
    • 2011
  • The satellite payloaded on the 2nd stage of KSLV-I is planned to perform CCAM(Contamination and Collision Avoidance Maneuver) not to collide with KM(Kick Motor). At the moment, the satellite should pass through low density environment not to be contaminated by KM plume due to residual thrust. Therefore, it is necessary to predict the flow field of KM plume by residual thrust. In this paper, DSMC (Direct Simulation Monte-Carlo) method, which is widely accepted to simulate in rarefied regime, is used to compute the density field of KM plume by residual thrust and the result of DSMC simulation was compared with that of FLUENT to validate it.

  • PDF

Design of PM Excited Transverse Flux Linear Motor of Inner Mover Type

  • Kang Do-Hyun;Ahn Jong-Bo;Kim Ji-Won;Chang Jung-Hwan;Jung Soo-Jin
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
    • /
    • v.5B no.2
    • /
    • pp.137-141
    • /
    • 2005
  • A transverse flux, PM-exited linear motor (TFM-LM) with inner mover was designed and built. Its output power density is higher and its weight is lower than those of the conventional PM exited linear synchronous motors (PM LSM). To obtain the maximum thrust force under the given volume, the thrust force density with respect to the ratio of the slot width and the length of pole pitch is analyzed by the 3-dimension finite element method (FEM). Finally, calculated static thrust forces was compared with the experimental values. The calculated and measured performance of the transverse flux, PM-exited linear motor with inner mover revealed great potential for system improvements by reducing the mass of the linear motor. For examples, when this motor was applied to a ropeless elevator, it was possible to increase the power density by more than 400% over the conventional PM-LSM. The results of this study recommend this type of motor for the ropeless elevator or gearless direct linear driving system.

Design and Analysis of a Dual-Stator Spoke-Type Linear Vernier Machine for Wave Energy Extraction

  • Khaliq, Salman;Kwon, Byung-il
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.6
    • /
    • pp.1700-1706
    • /
    • 2016
  • In this paper, a dual-stator, spoke-type linear vernier machine (DSSLVM) for wave energy extraction application was proposed. This machine is capable of producing a competitively high thrust force and force density at a low operation speed in direct drive systems. The operation principal and working of the proposed DSSLVM were studied. The stator core height is adjusted to improve the overall force density of the proposed machine while reducing the force ripple. To evaluate the advantages of the proposed DSSLVM, the main performance was compared with that of a recently developed linear primary permanent magnet vernier machine (LPPMVM). The proposed machine exhibited greater thrust force and force density, an improved power factor and lower force ripple with the same permanent magnet (PM) volume compared to the LPPMVM.

Measurement and Analysis of Back-EMF and Thrust of a Linear Brushless DC Motor (선형 브러시리스 DC 모터의 역기전력과 추력 측정 및 분석)

  • 이춘호;김용일;현동석
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.8
    • /
    • pp.183-192
    • /
    • 1998
  • In this paper, we measure the back-EMF and the thrust of a linear brushless DC motor along the relative position between coils and magnets in various speed environments in order to obtain the back-EMF and the thrust as a function of a motor position. The measured back-EMF function and thrust function of the position differ from the analytical ones within 5%. The measured back-EMF and thrust function can, then, be employed in controlling the thrust ripple of the linear motor. Furthermore, to minimize the torque ripple of the linear motor, we suggest the design method to shape the back-EMF and thrust function of the linear motor.

  • PDF

Formulation, Measurement and Analysis for the Static Thrust of LPM (LPM의 정추력 정량화 및 측정 분석)

  • Kim D.H.;Bae D.K.;Kim K.H.;Park H.S.
    • Proceedings of the KIPE Conference
    • /
    • 2003.07a
    • /
    • pp.304-307
    • /
    • 2003
  • Usually, the thrust of a Linear Pulse Motor(LPM) is calculated by magnetic equivalent circuit modelling method. Analytical thrust deviation exists to calculating magnetic flux density by using Permeance Modelling Method, Finite Element Method, and Velocity Electric Motive Force method. For calculating accuracy thrust by using these every method, tire thrust is calculated and compared by Lorentz Force method, Magnetic coenergy Method, and Maxwell correspondence forte Method. And that becomes Important factor at the comparison of each capacity and parameter of motor. So this study wants to compare and analyze measurement data and calculating data of the static thrust of LPM. and then we can get more accuracy method, calculating the static thrust of LPM.

  • PDF