• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.33-40
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• 1997

Recently, there are an increasing needs for high speed rotating spindle which is an important mechanical ele- ment for a high efficiency machine tool in order to shorten machining time and cut production costs. The heat gen- eration is the most important problem in the motor integrated spindle. In this study, the effects of temperature distribution and thermal behavior according to the oil-air lubrication and cooling conditions are investigate theo- retically and experimentally on the motor-integrated spindle under unloading condition. The experimental spin- dle system is composed with the angular contact steel ball bearings, oil-air lubrication, air or oil jacket cooling system. To analyze the thermal behavior and cooling characteristics for the motor integrated spindle, the analysis using the finite element method is carried out. The analytical results are compared with the experimental results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.192-195
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• 2005

Nanometer operating linear motor is difficult to control the nano-positioning because of the vibration between structures changing of mechanical friction force happened by properties of the vibration and heat caused by operating of a mover. Therefore, it is required to analysis the vibration and heat about a mover. In this paper, we will analyze the property of vibration through analyzing by using FEM a mover of linear motor developed in the non-load situation and suggest the direction of optimal design about a mover by using method of DOE, also try to find the solution to operate the linear motor stabilized through the reducing weight of mover considering the vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.840-845
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• 2004

Development of the linear motors is recently required to control a high-speed and high-resolution in the high-integrated and speed process industry. This paper presents vibration analyses as well as measurement standards of the newly developed linear motors through analyzing the vibration characteristics of the advanced products. Vibration experiments are conducted for identifying vibration level during operation. They are also included in the modal test to analyze dynamic characteristics. Analytic data using Finite Element Method (FEM) are compared with the results of the modal. The FEM and experiments make it possible to understand these characteristics. Further, through computer simulation for the behavior of moving part to be vibration source, the best acceleration pattern of moving part movement can be verified to achieve effective moving part positioning and reduce the vibration due to moving part movement.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.308-309
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• 2010

다중동력시스템용 전기자동차의 구동에 있어 부하가 적은 경우 한 대의 모터로만 운전을 하고, 경사로의 등판이나 화물의 양이 증가해 부하가 커지는 경우 하나의 엑슬에 결합된 두 개의 IPMSM모터를 사용하여 병렬형 인버터로 제어한다. 본 논문에서 개발한 인버터는 벡터제어 알고리즘 및 레졸버 위치센서를 적용하여 설계하였고 인버터 2개를 병렬 연결하여 Master와 Slave로 나눠 최적화 부하 분담 패턴으로 제어되도록 구현하였다. 제안된 제어기의 특성분석을 위해 PSIM시뮬레이션을 수행하였고, 제안된 방법의 유용성을 검증하였다.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.162-169
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• 2008

Dynamic characteristics of a control valve, which plays an important role in thrust control of liquid rocket engines, have been analysed by AMESim simulator modeling. A speed control method has been proposed for the control of the valve equipped with a BLDC motor and the performances of this control method have been proved in making a comparison between the predictions of simulation and experimental results. Moreover, it is shown that a control valve with a second pre-filter is enough stable to the flow disturbances. The speed control method for BLDC motor is more simpler than PI gain scheduling method for the application in complex flow system.

• Journal of computational fluids engineering
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• v.16 no.4
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• pp.1-6
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• 2011

Aerodynamic characteristics depending on the shape of an internal motor in a small-size sirocco fan for residential ventilation have been investigated. For the aerodynamic analyses of the sirocco fan, three-dimensional Reynolds-averaged Navier-Stokes equations are solved with the shear stress transport model for turbulence closure. The flow analyses are performed on hexahedral grids using a finite-volume solver. The validation of the numerical results at steady-state is performed by comparing with experimental data for the pressure and efficiency. In order to investigate the aerodynamic characteristics depending on shape of an internal motor in a sirocco fan, the reference shape is analyzed compared to the case without internal motor. Additionally, two shape parameters, height and width of the internal motor in a sirocco fan, are tested to investigate their effects on the aerodynamic characteristics. The results show that the shape of the internal motor in a sirocco fan is an important factor to improve the aerodynamic performances.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.42-49
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• 2015

The pressure oscillation induced by inhibitor in a solid rocket motor has been investigated by 3D large eddy simulation(LES) and proper orthogonal decomposition(POD). The vortex generation and breakdown at inhibitor are periodically observed between the inhibitor and the nozzle by flow-acoustic coupling mechanism. The excitation of pressure oscillation occurs as the flow impinges on the submerged nozzle head which recirculate in the cavity in rear dome of the motor chamber. The vortex generation frequency is closely related with the shedding frequencies of the detached vorticities at the inhibiter, which fairly compared with the experimental data.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1521-1522
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• 2015

선풍기는 모양과 용도에 따라서 탁상선풍기, 스탠드선풍기, 환기선풍기, 천장선풍기 등이 있으며, 최신식 선풍기에는 속도조절과 회전조절이 먼 거리에서도 가능한 리모컨식과 마이크로컴퓨터를 내장하여 자동적으로 바람의 속도를 조절하여 쾌적하게 잠이 들 수 있도록 프로그램이 갖추어진 것도 있다. 일반가정이나 사무실에서 흔히 사용되는 가전제품은 전기에 대한 비전문가가 사용하는 설비이기 때문에 관리소홀이나 취급상 부주의 등에 의해 화재가 종종 발생하는 실정이다. 특히 무더운 여름철이 지속되는 요즘 선풍기는 장시간 사용하는 제품으로 모터의 과열상태가 장시간 지속될 가능성이 높다. 본 연구에서는 선풍기에서 발생할 수 있는 화재위험성에 대하여 분석하고 정상조건에서 선풍기 자체 발열특성을 분석하는 실험과 모터가 과열될 수 있는 이상조건을 구현하여 가정용 회전기기에 발생할 수 전기화재 위험성을 고찰하였다.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.321-326
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• 2011

Aerodynamic characteristics depending on the shape of an internal motor in a small-size sirocco fan for residential ventilation have been investigated For the aerodynamic analyses of the sirocco fan, three-dimensional Reynolds-averaged Navier-Stokes equations are solved with the shear stress transport model for turbulence closure. The flaw analyses are performed on hexahedral grids using a finite-volume solver. The validation of the numerical results at steady-state is performed by comparing with experimental data for the pressure and efficiency. In order to investigate the aerodynamic characteristics depending on shape of an internal motor in a sirocco fan, the reference shape is analyzed compared to the case without internal motor. Additionally, two shape parameters, height and width of the internal motor in a sirocco fan, are tested to investigate their effects on the aerodynamic characteristics. The results show that the shape of the internal motor in a sirocco fan is an important factor to improve the aerodynamic performances.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.60-66
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• 2006

Notable are the burning rate characteristics of solid propellant burning at extremely high pressure(10000-20000 psia). The burning rate test using closed bomb shows the discontinuous increment around 4000 psia so that the exponent of burning rate(n) is almost double, from 0.4 to 0.8. The pressure-increasing rate of the test motor is about 300 times as high as that of the motor operating at the conventional pressure, less than 2000 psia, is, therefor the burning rate is augmented about 5-50 times. The performance prediction reflecting the pressure-change-rate effect are fairly comparable with the test data at various test conditions.