• Title/Summary/Keyword: single rotor equipment

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Optimum shape and process design of single rotor equipment for its mixing performance using finite volume method

  • Kim, Nak-Soo;Lee, Jae-Yeol
    • Korea-Australia Rheology Journal
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    • v.21 no.4
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    • pp.289-297
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    • 2009
  • We numerically analyzed flow characteristics of the polymer melt in the screw equipment using a proper modeling and investigated design parameters which have influence on the mixing performance as the capability of the screw equipment. We considered the non-Newtonian and non-isothermal flow in a single rotor equipment to investigate the mixing performance with respect to screw dimensions as shape parameter of the single rotor equipment and screw speed as process parameter. We used Bird-Carreau-Yasuda model as a viscous model of the polymer melt and the particle tracking method to investigate the mixing performance in the screw equipment and considered four mixing performance indexes: residence time distribution, deformation rate, total strain and particle standard deviation as a new mixing performance index. We compared these indexes to determine design parameters and object function. On basis of the analysis results, we carried out the optimal design by using the response surface method and design of experiments. In conclusion, the differences of results between the optimal value and numerical analysis are about 5.0%.

Modeling and Analysis of Drift Error in a MSSG with Double Spherical Envelope Surfaces

  • Xin, Chaojun;Cai, Yuanwen;Ren, Yuan;Fan, Yahong
    • Journal of Magnetics
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    • v.21 no.3
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    • pp.356-363
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    • 2016
  • To improve the sensing accuracy of the newly developed magnetically suspended sensitive gyroscope (MSSG), it is necessary to analyze the causes of drift error. This paper build the models of disturbing torques generated by stator assembly errors based on the geometric construction of the MSSG with double spherical envelope surfaces, and further reveals the generation mechanism of the drift error. Then the drift error from a single stator magnetic pole is calculated quantitatively with the established model, and the key factors producing the drift error are further discussed. It is proposed that the main approaches in reducing the drift error are guaranteeing the rotor envelope surface to be an ideal spherical and improving the controlling precision of rotor displacement. The common problems associated in a gyroscope with a spherical rotor can be effectively resolved by the proposed method.

Computational Flow Analysis around Coaxial Rotor Blades with Various Ducts (덕트형상에 따른 동축반전 로터블레이드 주위의 전산유동해석)

  • Kim, Su-Yean;Choi, Jong-Wook;Kim, Sung-Cho
    • Journal of the Korean Society of Visualization
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    • v.8 no.2
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    • pp.23-30
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    • 2010
  • Regarding the aircrafts with a rotor blade system, the miniaturization of them is limited due to the rotor blade length and the tail rotor system. To miniaturize an aircraft, an equipment is required that increases thrust and also shortens the length of the rotor blade. The present study will conduct the flow analysis for miniaturizing the aircraft by applying a duct to the coaxial rotor blade system without tail rotor. First, the verification on the calculated results was conducted through the computational flow analysis on the coaxial rotor blade system without a duct. Then, the flow analysis for the coaxial rotor blade systems was performed including Ka-60 duct, Single duct, Twin duct, and Double duct, respectively. From the numerical results, the thrust coefficient appeared higher with the duct than without a duct for the coaxial rotor blade system. Especially, in the case of Double duct, the thrust was improved due to the increase of incoming flow and the extension of the wake area. These results will be used as the basic concepts for miniaturizing the aircraft with the rotor blade system. The flow analysis on the coaxial rotor blade system including the fuselage remains as a future work.

Balancing Technic Based on Rotor Dynamics Analysis of Test Rig (Test Rig 동특성 분석에 따른 밸런싱 기술 적용)

  • Hwang, Dukyoung;Jung, Chonwoo;Park, Insun;Shin, Dongmin;Song, Jinseok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.27 no.2
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    • pp.204-212
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    • 2017
  • The rotor dynamics and balancing technic for rotating equipment during engineering and manufacture stage are to be carefully considered in order to minimize the operation troubles regarding vibration during commissioning stage. In this paper, the test rig, which includes the disks as balancing plane, is designed and manufactured, so that the characteristic of rotor dynamics can be analyzed such as critical speed and mode shape. The critical speed predicted through natural frequency analysis is verified by the actual measurement on bearing housing vibration during start-up condition of test rig. The low speed balancing and the operating speed balancing test are performed respectively with consideration of first critical speed, and the residual unbalance amounts are estimated in accordance with the relevant method described in API standard. In addition, the single and dual plane balancing are carried out on main disk and trim disk depended on phase information at each balancing step.

Parameter Measurement and Dynamic Performance Estimation of Synchronous Reluctance Motor Considering Iron Loss (철손을 고려한 자기저항 동기전동기의 정수 측정 및 동특성 예측)

  • Lee, J.S.;Hong, J.P.;Hahn, S.C.;Joo, S.W.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.58-60
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    • 1999
  • This paper presents dynamic performance prediction using Matlab / simulink after parameter estimation of synchronous reluctance motor considering iron loss. Test motor is 3 phase SynRM with the segmental rotor, rating power is 0.175KW. Experiment equipment is consists of testing motor, dynamometer, vector invertor dynamocontroller, and power analyser. The stator iron loss and rotor iron loss are modelled by additional windings on three-phase winding axis. These windings are transformed into d-q axis, and are represented as equivalent eddy current windings. P-Q circle diagram method and single phase standstill method are used to measure motor parameters considering iron loss.

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The study on Low-cost Position Sensor by a Single Opto-coupler for BLDC Drive (BLDC 구동을 위한 단일 옵토 카플러에 의한 저가형 위치센서에 관한 연구)

  • Kwon, Soon-Jae;Kim, Young-Su
    • Journal of Power System Engineering
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    • v.20 no.3
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    • pp.22-28
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    • 2016
  • Energy consumption rapidly increases with industrial development. therefore an interest in the efficiency of various power converters is increasing. Especially, the field of high-efficiency small motors widely distributed for industrial and family use is considered a very important field in terms of efficient energy usage, and accordingly, in the field of small electric equipment, the use of BLDC that allows high-efficiency drive in an inductor gradually increases. However, for the BLDC drive, information on the position of the rotor is essential. Both methods using a magnetic encoder and an optical encoder to detect the information on the position of the rotor obtain the information by three position sensitive devices, and if any one of these position sensitive devices fails to function, no positional information can be obtained, so there is a limitation in implementing a position sensor with high reliability. In the paper, proposes a new type of encoder that can obtain the positional information on the position of the rotor using a single position sensor in order to overcome the issues that it has to use numerous signal flows and that the reliability is reduced for the acquisition of positional information generated by using multiple position detectors. The encoder in the proposed method replaced the function of generating positional information from multiple sensors with the shape of the encoder plate and the capture function of MICOM. In order to verify the validity of the position detection technique by the proposed encoder, a prototype was produced, and an experiment using the capture function of DSP was conducted through this.

Visualization method of Clearance Design of Gas Turbine using Commercial Finite Element Analysis program (상용 유한요소 해석 프로그램을 이용한 가스터빈 간극 설계의 가시화 방법)

  • Han, Do Won;Kim, Yeong Chun;Kim, Kyung Chun
    • Journal of the Korean Society of Visualization
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    • v.17 no.1
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    • pp.78-84
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    • 2019
  • A gas turbine is the main equipment of a power plant that generates electricity by high-speed rotation of the rotor in a high-temperature environment. In particular, in the case of medium to large-sized gas turbines, the rotor is composed of a plurality of stages, and each component is exposed to different physical environments. Especially, in the case of the tip clearance of the turbine, it is a very important factor in the performance of the design items and the operation of the stable turbine, and a design considering the physical behavior of all major parts should be done. In this study, we will discuss the process of visualizing the physical behavior of turbine operating conditions and the method of designing tip clearance for stable operation by using commercial finite element analysis program for gas turbine assembly model and single product.

A Study on Mixing for Injection Molding of Ceramic Turbo-charger Rotor for Automobile Engine. (자동차엔진용 세라믹 터보차져로터의 사출성형을 위한 혼합에 대한 연구)

  • Chang, In-C.;Ko, Jin;Yoon, Jae-R.
    • Journal of the Korean Society for Precision Engineering
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    • v.9 no.4
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    • pp.109-117
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    • 1992
  • Mixing of ceramic-binder system was investigated experimentally and theoretically for application to Ceramic Injection Molding. Polypropylene, stearic acid, and paraffin wax were selected as the binder system, and silicon nitride fine powders were selected as the ceramic material. Single screw ectruder was employed as the mixing equipment. Theoretical analysis was performed to investigate the mixedness of mixture quantitatively. The analysis predicted average residence time average total strain, and average shear stress as a function of screw speed for mixtures of different volume fraction. Qualitative mixedness of mixture and characteristics of mixing were investigated by using SEM and EPMA. In addition, rheological properties of the mixture were investigated by using a capillary rheometer to examine possibility of injection molding.

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