• 한국산학기술학회논문지
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• 제11권1호
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• pp.13-20
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• 2010

본 연구의 목적은 Display 산업의 중요성에 주목하여 옥외 광고를 위한 LCD 패널용 콘솔(이하 'LCD 콘솔'이라 한다.)을 개발하는데 있다. 본 연구의 핵심 과제는 LCD 콘솔의 내부온도를 제어할 수 있도록 해주는 냉각시스템(Cooling System)을 개발하는 것이다. 냉각시스템은 상용화되어 있는 냉각휀(Cooling Fan), 히트싱크(Heat sinks), 열전소자(Thermo Electronic Module) 등의 제품들을 시스템적으로 통합시키는 응용기술로서 통계적 검정기법을 적용하여 개발되었다. 본 연구는 먼저 냉각시스템을 설계/제작한 후 실험을 통하여 냉각시스템 제어에 필요한 인자들의 설정 값들을 구하는 과정을 보였다. 이어서 개발된 냉각시스템을 이용하여 46인치 LCD Panel이 탑재된 LCD 콘솔을 설계/제작하고 실험을 통하여 완성품 LCD 콘솔의 성능을 확인하는 과정을 보였다.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3030-3034
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• 2015

새로운 엔진과 차량을 개발하여 엔진을 차량에 탑재할 때, 중요하게 고려해야 할 사항 중의 하나는 냉각 성능이다. 만약 냉각 성능이 열악하다면 엔진은 과열되어 파손되게 된다. 그러나 자동차회사에서 일반적으로 엔진은 차량보다 훨씬 빠른 시기에 개발이 진행되게 되어 엔진을 차량에 탑재한 조건에서 냉각 성능을 시험할 수 없다. 본 연구에서는 몇 가지 시험과 계산 결과를 이용하여 엔진의 냉각 성능을 추정하였다. 첫 번째로 엔진의 열정산 시험이 진행되었다. 두 번째로 냉각수 유동 시험이 진행되었다. 이 시험에서 라디에이터로 유입되는 유량을 구할 수 있다. 그리고 차량의 냉각 시험 성능 조건으로부터 차량의 부하와 속도를 구하고, 이로부터 엔진의 토크와 rpm이 계산되었다. 그리고 이러한 결과를 비교하여 엔진의 냉각 성능이 추정되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1059-1063
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• 2005

Development of a feed drive-system with high speed, positioning accuracy and thrust has been an important issue in modern automation systems and machine tools. Linear motors can be used as an efficient system to achieve such technical demands. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, due to great power loss and magnetic attraction of the linear motors heating and deflection problems occur. Therefore, it is necessary to design strong structure, cooling device with high efficiency and light weight construction in designing stage of linear motors. This paper presents an investigation into a structural design of linear motor system. In this research, a new concept of moving table with high stiffness and of cooling plate is also introduced. Structure analyses are performed by using a commercial code ANSYS in order to evaluate the design safety.

• 한국초전도ㆍ저온공학회논문지
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• 제6권1호
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• pp.38-42
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• 2004

The cryogenic system for 6.6 kV/200 A inductive superconducting fault current limiter (SFCL) was developed at Yonsei university in 2003. The sub-cooled nitrogen cryogenic system could be applied to not only SFCL but also many other applied high-Tc superconducting (HTS) devices like superconducting motor, superconducting generator and superconducting magnetic energy storage (SMES). Generally, the cooling capacity of GM-cryocooler depends on the load temperature. Therefore it is necessary to perform the cooling capacity test at no load condition to calculate the exact cooling power and heat load of cryogenic system. In this research, the cooling capacity test of GM-cryocooler was executed and the heat load of developed cryogenic system was calculated. The long run operation test results of sub-cooled nitrogen cryogenic system were successful in pressure and temperature condition. Moreover, the design and fabrication method of cryogenic system were introduced and the test results were described.

• 한국기계가공학회지
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• 제16권2호
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• pp.142-148
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• 2017

The objective of this study is to investigate the cooling characteristics of a heat sink for an LED headlight used in passenger cars. To this end, this study conducts the experimental and numerical analysis of the heat sink heated at constant heat fluxes without air flow applied. In the experiments, heat was transferred at a constant heat flux through the bottom of a heat sink. The measured temperature on pre-selected locations of the heat sink was in good agreement with the numerically predicted one. The experimental and numerical results indicate that the convective heat transfer coefficient for the natural convection mode was decreased by increasing the heat flux applied to the bottom of heat sink, lowering the cooling capabilities.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.172-176
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• 2001

A Stirling cryocooler is relatively compact, reliable, commercially available, and uses helium as a working fluid. The FPFD stirling cryocooler consists of two compressor pistons driven by linear motors which makes pressure waves and a pneumatically driven displacer piston with regenerator. A free piston and free displacer(FPFD) Stirling cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM(Korea Institute of Machinery & Materials). In order to evaluate the feasibility of using a linear motor driving cryocooler, prototype Stirling cryocooler with a nominal cooling capacity of 0.5W at 80K was designed, fabricated and tested. The prototype has achieved no load temperature of 51K and cooling power of 0.33W.

• 한국자동차공학회논문집
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• 제15권3호
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• pp.79-84
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• 2007

Recently it is strongly required to develop the better fuel economy as well as basic power performance based on strict emission legislation. This paper focuses on studies of the engine cooling and ancillaries system among fuel economy factors in the developing stage. Firstly through the analysis of the current specifications, it is assessed whether each components may be designed properly, not overdesigned. Secondly, it is predicted how the fuel economy of each components can be improved. Finally the results are confirmed by vehicle field test equppted with the updatedcomponents. This study found good agreementbetween the prediction and the field test on the vehicle fuel economy improvements of the heavy duty engine vehicle with updated components such as engine cooling and ancilliaries.

• 한국자동차공학회논문집
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• 제13권2호
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• pp.10-15
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• 2005

This study was initiated to evaluate the cooling performance of CAC (charged air cooler) and radiator in the engine room of a mini bus. So we had firstly to predict the mass flow rate coming from radiator grille and front bum per opening using computational fluid dynamics (CFD) simulation based on 3D configuration. And simulations were carried out for different cooling module layout and bum per opening hole size on sam e vehicle operating condition. Simulation results show that CAC cooling performance at reverse protecting plate-applying model was much efficient than that of the bum per opening hole size-increasing model in IMTD point of view. Part of the CFD simulation results was com pared to with experimental data. It was confirm ed that the CFD approach using STAR-CD based on pursuing no-com promise solution could provide design engineers with useful design information in the early design stage of vehicle development.

• 한국정밀공학회지
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• 제19권6호
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• pp.184-191
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• 2002

This paper presents the thermal behavior of a synchronous linear motor with high speed and force. Such a linear motor can successfully replace ball lead screw in machine tools because it has a high velocity, acceleration and good positioning accuracy. On the other hand, low efficiency and high heating up during operation are disadvantage of linear motors. For the application of linear motors to machine tools a water-cooling system is often used. In this research, structure of the linear motor and water cooler is changed to improve the thermal behavior of the linear motor. Some important effects of an integrated cooler, an U-cooler and a thermally symmetrical cooler are presented.

• Journal of Power Electronics
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• 제9권6호
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• pp.960-968
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• 2009

This paper presents a design optimization process for interior permanent magnet synchronous motors (IPMSM) for hybrid electric compressors (HEC) which are applied to hybrid electrical vehicles. A hybrid electric compressor is composed of an electric motor driving section and an engine driving section which is connected to the engine by a pulley belt. A hybrid electric compressor driving motor requires half of the full driving power of a compressor. Even though an engine is not operated at the idling stop mode, the electric motor drives the air-conditioner compressor by itself so that the air conditioning system can produce its minimum cooling capacity. In this paper, the design optimization of an IPMSM for a 42 (V) applied voltage system is studied using the design of experiment (DOE) and response surface method (RSM) of 6sigma. The driving characteristics of this motor drive system are measured and analyzed by experiment.