• International Journal of Automotive Technology
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• 제7권7호
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• pp.841-846
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• 2006

This paper presents a numerical approach to optimizing vehicle fuel economy in a higway bus. The method described is based on using a commercial software vehicle simulation to identify the relative efficiency of each of the vehicle systems, such as the engine hardware, engine software calibration, transmission, cooling system and ancillary drives. The simulation-based approach offers a detailed understanding of which vehicle systems are underperforming and by how much the vehicle fuel economy can be improved if those systems are brought up to best-in-class performance. In this way, the optimum vehicle fuel economy can be provided to the vehicle customer. A further benefit is that the simulation requires only a minimum number of vehicle testing for initial validation, with all subsequent field test cycles performed in software, thereby reducing development time and cost for the manufacturer.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.103-110
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• 2004

The major trend in global automotive market is changing drastically in the way that a vehicle FECPS(Front End Cooling Pack System) is designed and manufactured as an assembly part. The system can encompass many functions, be assembled into a vehicle as a module, and reduce the production cost as well as time. The FECPS consists of an impact beam, an aluminum condenser and a radiator, a carrier and a cooling fan with a BLDC motor. In order to predict the performance of a FECPS accurately, it is essential to properly model the air flow field through various heat exchangers, such as a condenser or a radiator. In this study, the flow field of the system is measured by a PIV(Particle Image Velocimetry) system. The result is compared with that measured with multi-channel anemometer.

• 한국추진공학회지
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• 제25권2호
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• pp.98-109
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• 2021

극초음속 비행체용 능동냉각시스템의 전체적인 운용 성능을 결정하는 주요 요소는 크게 탄화수소흡열연료, 재생냉각 채널, 시스템 소재 및 구조로 구분되며, 그 중에서도 효율적인 재생냉각시스템 개발을 위한 일련의 연구는 탄화수소 항공유의 흡열반응 성능 향상으로부터 시작된다. 따라서 이전 연구에서는 탄화수소 항공유 자체의 흡열분해 특성에 대한 광범위한 연구 동향을 정리하였으며, 본 연구에서는 그에 대한 후속 연구로서 효과적인 흡열분해 특성 개선 및 성능 향상 방안으로 다양하게 시도되고 있는 촉매 분해와 수증기 개질 연구들에 대한 세부기술 분석을 수행하였다.

• Design & Manufacturing
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• 제16권2호
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• pp.46-52
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• 2022

As the consumer market in the eco-friendly vehicle industry grows, the demand for water pump in a electric car parts market. This study intend to propose a mathematical model that can verify the effect of improving thermal properties when a non-conductive cooling filler liquid is introduced into an electric vehicle water pump. Also, the pros and cons of the immersion cooling method and future development way were suggested by analyzing the cooling characteristics using on the derived analysis solution. Thermal characteristics analysis of electric water pump applied with non-conductive filler liquid was carried out, and the diffusion boundary condition in the motor body and the boundary condition the inside pump were expressed as a geometric model. As a result of analyzing the temperature change for the heat source of the natural convection method and the heat conduction method, the natural convection method has difficulty in dissipating heat because no decrease in temperature due to heat release was found even after 300 sec. Also, it can be seen that the heat dissipation effect was obtained even though the non-conductive filling liquid was applied at the 120 sec and 180 sec in the heat conduction method. It has proposed to minimize thermal embrittlement and lower motor torque by injecting a non-conductive filler liquid into the motor body and designing a partition wall thickness of 2.5 mm or less.

• 한국자동차공학회논문집
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• 제14권5호
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• pp.181-185
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• 2006

A study to get better vehicle fuel economy is described based on an express bus. The approach is based on using a commercial software vehicle simulation to identify the relative efficiency of each of the vehicle systems, such as the engine hardware, engine software calibration, transmission, cooling system and ancillary drives. The simulation-based approach offers a detailed understanding of which vehicle systems are underperforming and by how much the vehicle fuel economy can be improved if those systems are brought up to best-in-class performance. In this way, the optimum vehicle fuel economy can be provided to the vehicle customer. A further benefit is that the simulation requires only a minimum of vehicle testing for initial validation, with all subsequent field test cycles performed in software, thereby reducing development time and cost for the manufacturer.

• 한국항해항만학회지
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• 제36권1호
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• pp.35-41
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• 2012

본 논문은 수중체용 냉각 시스템에 관하여 분석하고, 수중체에 최적화된 냉각 제어 알고리즘에 관하여 연구하였다. 수중체용 대용량 추진 전동기는 동손 및 철손으로 인해 발생하는 고열로부터 전동기를 안정적으로 보호하기 위해 청수를 이용한 냉각 시스템이 사용된다. 이 냉각 시스템은 전동기의 온도를 유지하기 위해 외부 환경 및 전동기의 회전수 유지시간에 따라 해수 및 청수 펌프 RPM을 조절한다. 본 논문에서는 제안하는 냉각 시스템의 검증을 위한 시뮬레이션 프로그램을 구성하였으며, 다양한 제어 기법을 적용하여 냉각 수행 능력을 검증하였다. 그 결과 제안하는 냉각 알고리즘은 열적 안정성과 효율이 기존 냉각 알고리즘에 비해 높음을 확인하였다.

• 동력기계공학회지
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• 제21권6호
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• pp.46-55
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• 2017

Due to the arise of natural disasters caused by global warming, consumers have more interest in the fuel efficiency of their vehicles, and fuel efficiency became an important factor in comparing vehicles. In this market situation, methods to measure fuel efficiency has become one of the main interests of vehicle related organizations and laboratories, and the current method to measure fuel efficiency is to follow the notification established by the ministry of trade, industry and energy, ministry of environment, and the ministry of land, infrastructure and transport. In this study, we analyze the influence of vehicle fuel efficiency according to test temperature and cooling fan condition which have the possibility to cause difference in fuel efficiency. The analysis results of the influence of the fuel efficiency according to the test temperature, the difference of the fuel efficiency of the test temperature ($21{\sim}29^{\circ}C$) within the allowable range of the notification showed a maximum difference of 2.9%. Therefore, it is necessary to consider the introduction of a test method that permits only the temperature change based on the reference point as the allowable range even in the test within the allowable range. The analysis of the influence of the fuel efficiency according to the cooling method showed no significant effect, and it seems reasonable to maintain the test method of the current notification.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5430-5437
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• 2011

본 연구의 목적은 친환경 무공해 승용 차량에 적용되는 전동식 냉방시스템의 성능특성을 실차에서 확인하는 것이다. 이를 위하여 인버터로 구동되는 전동식 스크롤 압축기를 적용한 전동식 냉방시스템을 설계 및 제작하여 수소 연료전지 자동차에 설치하여 다양한 주행도로 조건에서 실험을 진행하였다. 주행조건의 변화는 시험차량에 장착된 전동식 냉방시스템의 성능에 영향을 주었으며, 고속 및 일반도로 주행조건에서 냉방시스템의 성능이 정지조건에서 냉방시스템의 성능보다 우수하게 나타났다. 또한, 외기온도가 $20.0^{\circ}C$에서 $30.0^{\circ}C$로 증가함에 따라 고내 온도는 평균 $5.2^{\circ}C$ 더 적게 감소하였다.

• 오토저널
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• 제16권6호
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• pp.1-8
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• 1994

• 한국항공우주학회지
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• 제32권4호
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• pp.111-117
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• 2004

케로신과 액체산소를 추진제로 하며, 10톤을 설계 추력으로 하는 우주 발사체의 2단용 액체로켓엔진의 재생 냉각 특성에 대한 해석적 연구를 수행하였다. 또한 보조적인 냉각 방법으로서 노즐 확장부에는 대기로의 복사 방열에 의한 냉각을 적용하였다. 본 연구를 통해, 케로신을 연료로 하는 10톤 추력의 2단용 액체로켓엔진에서 재생냉각과 복사 냉각에 의한 냉각 기구만으로는 소재의 열 및 열구조적인 불안정성과 냉각채널에서의 과다한 압력강하에 의해 적합하지 않다는 것을 확인하였다.