• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.684-689
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• 2004

In this study, a experimental method has been introduced for the various exhaust pipe geometry of 4-stroke single cylinder engine. The main experimental parameters are the variation of exhaust pipe diameters and lengths, to measuring the pulsating flow when the intake and exhaust valves are working. As the results of experimental test, the various exhaust geometry were influenced strongly on the exhaust pressure. As the exhaust pipe diameter was decreased, the amplitude and the number of compression wave in exhaust pressure was increased. According to decreasing pipe diameter, the number of compression wave in exhaust pressure was decreased. When the pipe diameter was increase, the second amplitude was increased.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.614-615
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• 2005

• 한국유체기계학회 논문집
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• 제15권3호
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• pp.25-31
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• 2012

A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.200-204
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• 2005

A few intake stations have vibration problems caused by pumps, motors and pipes. The vibration transffered from pumps, motors and pipes excites buiding severely. Therefore, the crack is generated on building wall and people who work at intake station are damaged. In this paper, the vibration and noise have been measured and analyzed for pumps, motors, pipes and building at intake station. Also, the cause of vibration and noise is identified. Finally, the reference of vibration and noise is established using results of measurement.

• Journal of Advanced Marine Engineering and Technology
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• 제14권4호
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• pp.72-80
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• 1990

In this paper, the gas dynamic effects of the suction pipe systems which have resinators are investigated on the volumetric efficiency are theoretically investigated by the engine performance simulation program which has been already developed. As the results, the optimum design method of the suction pipe system which has the overall high the flat characteristic curve of volumetric efficiency is developed in case of one cylinder engine.

• 한국수자원학회논문집
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• 제50권8호
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• pp.579-586
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• 2017

기능성 스크린이 부착된 집수관의 정량적인 취수량을 분석하고, 여과 재료를 통한 부유물질 및 탁도의 개선효과를 알아보기 위해 네 단계의 연구방법을 제시하였다. 첫 번째 단계에서는 소규모의 실험장치를 구성하여 실증 플랜트 여과 재료의 구성 방법을 결정하였고, 두 번째 단계에서는 견본 장치를 구성하여 기능성 스크린이 장착된 집수관을 통해 유량 값을 측정하였다. 세 번째 단계에서는 각각의 여과 재료에 대해서 탁도의 상태를 달리하여 유량을 측정하고, MODFLOW를 이용하여 투수계수를 추정하였다. 마지막으로 견본 장치를 MODFLOW로 수치모델을 구성하여 세 번째 단계에서 추정된 투수계수를 각각 적용하고 취수량을 분석하였다. 0 NTU일 때 추정된 투수계수 적용 결과 실제 관측 유량에 비해 모델링 결과는 39.96% 높게 나타났다. 이에 비해 100~120 NTU일 때 추정된 투수계수 적용 결과 유량의 차이는 9.41% 높게 나타났다.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.538-548
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• 2016

The purpose of this study is to identify the possibility of effective tuning works, understand the characteristics of tuning engine, and analyse the basic data of engine tuning inspection corresponding to the safe operation and environment of a driving gasoline car. The effects of tuning on the characteristics of performance and exhaust emissions under a wide range of engine speeds are experimentally investigated by the actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating at four types of non-tuning, tuning 1, 2 and 3. The tuning parts in the gasoline engine are the intake manifold, intake pipe and air filter. In the experiment, the output, torque and air-fuel ratio of the five-speed automatic transmission vehicles were measured at the chassis dynamometer(Dynojet 224xLC) with one person on board. The exhaust emissions of $NO_X$, THC, CO, $O_2$ and $CO_2$, and excess air ratio(${\lambda}$) at the other chassis dynamometer(DASAN-MD-ASM-97-KR-HD) were also measured by the idle/constant-speed mode(ASM2525 mode) test method. It is found that the actual air-fuel ratios of non-tuning and tuning engines were shown to be lower than the stoichiometric air-fuel ratio with increasing engine speed, and the actual air-fuel ratio of non-tuning engine was slightly higher than those of tuning engines when the engine speed is more than 4000 rpm. The output was significantly increased by the tuning whereby the maximum output of tuning engine was more increased to approximately 117.64% than that of non-tuning engine. In addition, CO, THC and $NO_X$ emissions of non-tuning and tuning engines measured by the constant-speed test mode were all satisfied with the inspection standards. CO emission was increased, while THC and $NO_X$ emissions were reduced by tuning.

• 복합신소재구조학회 논문집
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• 제6권2호
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• pp.91-96
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• 2015

GRP pipe (Glass-fiber Reinforced Plastic Pipe) lines making use of FRP (Fiber Reinforced Plastic) are generally thinner, lighter, and stronger than the existing concrete or steel pipe lines, and it is excellent in stiffness/strength per unit weight. In this study, we present the result of field test for buried GRP pipes with large diameter(2,400mm). The vertical and horizontal ring deflections are measured for 387 days. The short-term deflection measured by the field test is compared with the result predicted by the Iowa formula. In addition, the long-term ring deflection is predicted by using the procedure suggested in ASTM D 5365(ANNEX) in the range of 40 to 60 years of service life of the pipe based on the experimental results. From the study, it was found that the long-term vertical and horizontal ring deflection up to 60 years is less than the 5% ring deflection limitation.

• 대한기계학회논문집
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• 제15권5호
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• pp.1674-1682
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• 1991

본 연구에서는 4기통 고속 가솔린 기관의 흡기관 내 유체유동이 체적효율에 미치는 동적효과를 고려하여, 흡기관에 임피던스를 이용한 음향학적 방법을 이용해서 흡기관 최적설계를 해석하고, 기관실험을 통해 그 신뢰성을 확인하고자 한다.

• 오토저널
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• 제13권6호
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• pp.72-81
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• 1991

In this study, the analytic investigation of the unsteady flow in the intake and exhaust pipes has been carried out using the method of characteristics in one direction to predict volumetric efficiency. Based on the calculated volumetric efficiency, three zone predictive analysis using Wiebe function was applied to predict the engine performance and the results were compared with experiment. Mixture in the cylinder is subdivided into three zones during combustion process in this analysis; adiabatic core zone, thermal boundary layer zone and unburned zone. In each zone, pressure, temperature and gas composition have been calculated. In conclusion, it is possible to take account of the intake and exhaust pipe tuning effect in predicting the engine performance, by the analytic solution of the unsteady flow in the pipes, and comparison of prediction with experimental results shows a good agreement on the pressure variation in the intake and exhaust pipes which has a direct influence on the volumetric efficiency and performance of the engine.