• Proceeding of EDISON Challenge
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• 2012.04a
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• pp.77-80
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• 2012

초음속 흡입구는 설계점에서 안정적으로 작동하지만 설계점 밖에서는 엔진성능이 급격히 감소하거나 층 격파 불안정 문제가 발생할 수 있다. 초음속 흡입구의 일반적인 특성을 파악하기 위해 2단 꺾임각을 갖는 외부 압축식 2차원 흡입구를 설계하고 EDISON_열유체 시스템을 이용하여 최종적으로 설계 마하수 2.5에서 작동하는 형상을 얻었다. 그러나 설계 마하수 이하의 영역에서는 충격파-경계층, 충격파간 상호작용으로 인해 유동에서 박리가 발생하고 최종적으로 흡입구 목을 질식시켜 아임계 상태로 천이된다. 이를 해결하기 위해 유동 제어 방법 중 하나인 bleeding을 이용하여 경계층을 제거하거나 유동의 박리를 방지하여 충격파를 cowl lip 전방에 안정하게 고정시킬 수 있었으며, 결과적으로 목적하였던 마하수 2.0에서 2.5에 이르는 작동 영역에서 강건하게 운용될 수 있는 초음속 흡입구를 설계하였다.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.589-592
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• 2005

In general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Unfortunately in order to design the sump station, the reasonable code or the standards weren't presented yet in Korea. Thus, some researchers had often referred the HI code, JSME code or CEN code to design the sump station. This study aims to prescribe the standard of sump design which were matched well the Korean pump station. Thus, the HI code and TSJ code would be interpreted fully to Korean language, the part of interpreted clauses of the western codes would be selected to compose the standard.

• The KSFM Journal of Fluid Machinery
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• v.13 no.5
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• pp.54-57
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• 2010

The purpose of this article is to diagnosis all aspects of waste pneumatic transportation system, in order to provide everyone interested in the subject with a optimal design and management of the system. The results of the analyzed inlet boxes were especially designed for customers' convenience and automatically operation, side air intake, ensure good wear. And key of pipelines were showed design standard as degree of an angle. Also, the system is mostly equipped with automatic control and watch conducted inside the waste collection facilities, and it will cut down excessive manpower and be able to be managed by least trained personnel.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.119-120
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• 2002

소각로, 산업공정 등 다양한 배출원을 가지고 있는 다이옥신은 식품, 피부접촉, 대기 및 토양 통의 매체를 통하여 인간의 건강과 자연 생태계에 유해 영향을 미치고 있다. 환경 중 다이옥신의 배출량은 극미량이기는 하나 높은 지용성 물질로써 환경 매체간 이동 및 먹이사슬을 통해 생체농축현상을 일으키는 것이 밝혀지면서 그로 인한 유해성 야기되기 시작하였으며, 특히, 2001년 미국 환경보호청에서 다이옥신에 대한 재평가를 통해 2,3,7,8-TCDD는 인체 발암물질로, 다이옥신은 인체 발암 유발 가능 물질로 분류하고 있어, 선진국에서는 다이옥신에 대한 적극적인 연구가 진행되고 있다. (중략)

• Tunnel and Underground Space
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• v.5 no.1
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• pp.48-56
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• 1995

Recently, most of the underground excavation works are adopting heavy duty mobile diesel equipments which have outstanding merits in view of efficiency. However, these equipments are causing hygienic problems to the workers due to the various hazardous exhaust contaminants. Considering that there are always dead end workings in underground excavation sites, it is very important how to supply enough airflow to the workings to dilute diesel exhaust contaminants. This paper introduced the theoritical mechanism and actual trends of exhaust contaminants of diesel equipments under operation at local mines and suggested the design method of intake air volume in underground excavation workings using diesel equipments.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.10
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• pp.2690-2698
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• 1995

Fuel atomization and mixture formation in an gasoline engine has influence on the engine performance and pollutant emission. The throttle valve installed in an intake system plays a greater role in control of mixture quantity in accordance with engine drive condition. In this study, the characteristics of secondary atomization developed at the downstream of the valves were observed using an image processing method. Two major kinds of valves, solid and perforated ones, are chosen in order to compare the valve performance with the experimental parameters of air flow rate, valve opening angle, and valve shapes. For the perforated valve, we can obtain the relatively small sized droplets, and nearly uniformed and dense distributed sprays with low loss coefficient than for the solid valve.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.80-86
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• 1996

In order to decrease fuel comsumption rate and emissions, lean burn engine which has equipped swirl control valve, is investigated experimentally on the test bench. Single cylinder engine was used to test the combustion and emission performance with 4 kinds of swirl valve. Decrease in the carbon monoxide, hyerocarbon and specific fuel consumption was shown at the lean condition, which means that a good choice of swirl valve on the given intake port geometry can be used to increase the combustion efficiency and lean limit.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.2
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• pp.149-153
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• 2003

Besides the fuel spray behavior and combustion chamber shape. an air motion has a key role on exhaust gas emission and performance in a DI diesel engine. A swirl ratio represents the ratio of the intake swirl velocity to the engine speed. The main purpose in this work is to investigate the effects of the swirl ratio to the combustion characteristics. A shroud valve machined to change the swirl ratio. Test was carry out by changing the engine speed, nozzle diameter and swirl ratio in a single cylinder diesel engine. From this study, the optimized combustion was found at swirl ratio 2.7. And it was also found that the increasing the maximum cylinder pressure with an increasing swirl ratio lead to decrease a smoke and to increase NOx.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.86-95
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• 1996

This study was on the pollution emissions of the Ultrasonic fuel feeding system in gasoline injection vehicle. This work measured th SMD of the fuel, and compared the characteristics through chassis dynamometer and highway road test by the conventional vehicle. And this work measured vacuum degree, turbulence intensity and the rate of fuel consumption according to intake air velocity with swirler. The results are as followed; The effects of the vehicle installed the ultrasonic fuel feeding system are better than those of the conventional vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.24-33
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• 1999

This paper investigate the effects of the variations of engine operation condition in the flame kernel formation and developmnet . A model for calculating the initial kernel development in spark ignition engines is formualted. It considered input of electrical energy, combustion energy release and heat transfer to the spark plyg, cylinder head, and unburned mixture. The model also takes into accounts strain rate of initial kernel and residual gas fraction. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy and turbulent flame expansion. Flame kernel development also influenced by engine operating conditions, for example, EGR rate, air-fuel ration and intake manifold pressure.