• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.680-686
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• 2004

Recently, the application of variable geometry turbocharger (VGT) to the high speed direct injection (HSDI) diesel engine has gained more and more interest in automotive industry. A steady state experimental investigation has been undertaken on a 1.5L HSDI diesel engine to verify the benefits of VGT comparing to the standard engine having a waste gate turbocharger (WGT). Specifically, part load performances (e.g., fuel economy and emission) have been investigated under various vane angles of the VGT. The results show that the real exhaust gas recirculation (EGR) rate as well as the pumping loss is very important to improve break specific fuel consumption (BSFC). It was previously known that the pumping loss only is a main parameter. In addition, the trade-off relationship between BSFC and NOx according to boost pressure, and the decreasing tendency of NOx with increasing real EGR rate have been verified. 1-D numerical analysis also has been performed, and the numerical results are in good agreement with experimental results.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.942-948
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• 2011

The performance of a supercharger for vehicle using solar cell attached on the exterior of a car, an auxiliary battery, and an air compressor was evaluated in this study. This supercharger is composed of a solar cell of 40W, a battery of 60 Ah, an air compressor of 17 A, 8 $kgf/cm^2$ and an air tank of 8L. It takes about 6 days to charge the battery with the solar cell and the high pressure air of 8L can be supplied about 70 times to engine intake with this battery. The intake pressure increased by about 20~40% with this supercharger. The vehicle power and accelerating performance are enhanced by 87% and 50% each in the low speed range. But the performance improved little in the high speed range because of the rather constant flow rate of air supplied by this type of supercharger.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.181-186
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• 1999

The objective of present work is to investigate the performance characteristics of three-lobe Roots type supercharger for the applications of low-compression and high-expansion ration gasoline engine. A performance test was conducted to obtain the drive power, volumetric efficiency, adiabatic efficiency and the influence of performance factors of supercharger . In order to analyze the supercharging characteristics, the experiments are made on operating parameters such as the supercharger speed, pressure ration and inlet temperature on the supercharging performance of the Roots type supercharger . Based on experimental results, the drive power and flow rate of supercharger increased with supercharger speed.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.37-42
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• 2003

This research was carried on an 8100cc turbo-charged heavy duty diesel in the application of a cooled-EGR. Exhaust and intake manifold were modified and an electronically controlled EGR was installed in order to investigate engine performance and exhausted emission characteristics. High pressure route was designed in the compact form on the purpose of practicability in this cooled-EGR system, which constitutes a venturi tube to maintain pressure difference between exhaust manifold and compressor, an EGR cooler, an EGR valve and a solenoid valve.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.195-201
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• 1998

This study aims at the optimal design of rotors and the development of screw type Supercharger of CNG-fueled engine for commercial vehicle. Based on the new rotor profile, an advanced oil free type Supercharger has been developed, which can achieve higher adiabatic efficiency and lower manufacturing cost. The performance test of screw type Supercharger has achieved high volumetric efficiency and the durability on the bench of performance test has also been established in the compact body.

• 오토저널
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• 제10권4호
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• pp.7-13
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• 1988

오늘날의 기관은 고출력 뿐 아니라 1) 저속으로부터 고속까지의 전영역에 걸쳐 flat하고도 높은 torque를 확보하고 또한 고도특성이 우수한 기관인 동시에 2) 소음의 저감을 도모하고, 보다 저연비와 보수, 유지가 간편할 것등을 목표로 하고 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권8호
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• pp.1009-1015
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• 2011

본 연구에서는 고팽창사이클의 경우 가변밸브시스템을 구성하여 흡기밸브 닫힘시기를 늦추는 방식으로 실현하였고, 저압축에 따른 흡입공기의 감소는 과급압력으로 해결하였다. 이와 같이 디젤기관에 아트킨슨사이클을 실현하여 엔진의 열효율향상 가능성을 알아보았다. 그 결과 흡기밸브 닫힘시기 ABDC $40^{\circ}$ 부터 ABDC $80^{\circ}$ 까지 전 영역에 걸쳐 열효율 및 출력의 향상이 있었다. 다만, 흡기밸브 닫힘시기가 ABDC $70^{\circ}$이후로는 열효율 증가 폭이 둔화되는 경향을 보였다. 위와 같은 연구결과 저속 디젤-아트킨슨사이클화의 최적 연소조건은 흡기밸브 닫힘시기가 ABDC $70^{\circ}$전후로 보이며, 고부하영역이 저부하영역보다 더 효과적으로 나타났고, 중부하영역에서 기관운전은 안정적이었다. 이때 정미열효율은 통상의 디젤기관보다 평균 약 12.5% 높게 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.379-387
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• 2011

최근 디젤엔진에서 엔진성능향상 및 배출가스저감을 위해 저압 EGR시스템에 대하여 연구개발이 활발히 진행되고 있다. 저압 EGR시스템은 EGR율에 따라 과급압력이 영향을 받지 않기 때문에 PM을 최소 화하면서 $NO_x$를 저감할 수 있는 장점을 갖고 있다. 본 연구에서는 2.0L급 고속직분사방식의 엔진에서 출력 및 연비저하로 EGR적용이 어려운 엔진회전수 2000 rpm, BMEP 1.0 MPa, 과급압력 181.3 kPa인 중부하 운전영역에서 서로 다른 EGR시스템에 따른 엔진성능 및 배출가스 특성을 실험적으로 연구하였다. 그 결과로서 기존의 고압 EGR시스템 또는 배압조절밸브를 사용하는 저압 EGR시스템에 비하여 ETC를 적용한 저압 EGR시스템이 $NO_x$ 배출특성은 큰 차이가 없는 반면에, 연비 및 열효율이 향상되고 PM 저감에 연소효과를 나타내고 있음을 확인하였다.

• 동력기계공학회지
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• 제12권1호
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• pp.13-19
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• 2008

In this study, a variable induction and exhaust system is applied to turbocharged diesel engine to improve the volumetric efficiency, especially, in a low and transient engine speed range where much of the pollutant matters are expelled out. The volumetric efficiency is known as one of the most important factor which affects significantly engine performance, fuel economy and further emission and noise level. As the torque increase with the engine speed up, the gas flow in an exhaust pipe become pulsating and then has an effect on boost up capacity of air charging into the cylinder and expelling capacity to atmosphere simultaneously. But at a low and idling speed, the pulsation effect was not so significant. Accordingly, resonator was employed to compensate their loss. The variable induction system consists of the secondary pipe, resonator, intercooler, and torque variance were examined with extended operating conditions. In the mean time, for interpretation and well understanding for the phenomena of wave action that arising during intake and exhaust process between turbocharger and variable intake system, the concept of the combined supercharging was introduced. Some of results are depicted which deal with a pressure history during valve events of induction process. Consequently, by the governing of these phase and amplitude of pulsating wave, it enables us to estimate and evaluate for the intake system performance and also, designing stage of the system layout.

• 한국산학기술학회논문지
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• 제11권11호
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• pp.4137-4144
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• 2010

본 논문에서는 승용디젤엔진에서 유해배출물을 저감시키는 동시에 고연비를 달성하기 위하여 2단 터보과급기와 EGR 장치를 장착한 디젤엔진에 대하여 EGR 배열 방식이 EGR율에 미치는 영향을 분석하기 위하여 시뮬레이션을 수행하였다. 이를 위하여 AMESim을 사용하였고 엔진 부품을 위하여 IFP Engine Library를 사용하였다. 고압, 저압, 반저압의 3가지 배열 방식이 고려되었다. 일반적으로 많이 사용되는 고압 방식과 저압 방식의 EGR 배열이 공연비 21에서 각각 6.4%, 10.0%의 EGR율을 보인 반면, 두 방식의 혼합형인 반저압 EGR 배열 방식의 EGR율은 18.0%의 값을 보였다. 따라서 2단 터보과급기와 EGR 장치를 장착한 엔진 설계시 엔진 성능과 유해배출물 발생량의 관점에서 반저압 방식 EGR 시스템이 적절함을 보였다.