• 한국자동차공학회논문집
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• 제23권3호
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• pp.299-306
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• 2015

Turbocharged gasoline direct injection engine is one of promising technologies in the automotive industry. However, reduction in turbo-lag under transient operation is one of important challenging points to improve drivability. Engine transient performance was investigated in a 4-cylinder 2.0 L turbo-gasoline direct injection (T-GDI) engine using Inconel and TiAl (Titanium Aluminide alloy) turbine wheel turbochargers. The TiAl turbocharger performed superior transient boost pressure and torque rises under various engine transient operation conditions. These were mainly due to lower turbine rotational inertia of TiAl turbocharger. The Maximum boost pressure and torque build up were founded in 1500 rpm and 2000 rpm, instant load change from 20% to 100% of pedal position.

• 한국추진공학회지
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• 제23권1호
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• pp.101-107
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• 2019

고고도 장기체공 무인기의 추진 시스템에 다단 터보차저 가솔린 왕복기관 시스템의 적합성을 평가하기 위하여 성능 시뮬레이션을 진행하였다. Ricardo사의 1-D 엔진 시뮬레이션 WAVE를 사용하여 다단 터보차저를 포함한 엔진 시스템을 모델링하였다. 엔진 모델은 양산 2.4L 가솔린 4기통 엔진의 제원을 반영하였다. 터보차저 모델에는 상용 터보차저의 성능 맵을 적용하였다. 고도 60,000ft에서 엔진의 적정 흡기 압력을 확보하기 위해 3단 터보차저 및 인터쿨러를 구성하였다. 웨이스트 게이트는 하나로 구성하였다. 이를 통해 지상부터 고고도까지의 엔진 시스템 정상 상태 운전성을 평가하였다.

• 오토저널
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• 제7권2호
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• pp.64-79
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• 1985

Engine performances and emission characteristics were investigated, using a experimental single cylinder engine with methanol-LPG(butane) fuel blend. The results were compared with the case of neat methanol and gasoline. The blending ratio of methanol to LPG was reasonable at 90 : 10(M90) and in using M90, the engine performances including output, brake specific fuel consumption and brake thermal efficiency, were better than those of neat methanol and gasoline. CO emission of M90 was lower than that of meat methanol by 15% and lower than that of gasoline by 35%. HC emission of M90 was also lower than that of gasoline by 46-85% in the whole range of .phi. The concentration of NOx emission of M90 was lower than that of gasoline and higher than that of neat methanol.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.343-344
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• 2014

Ethanol as fuel of Spark Ignition Direct Injection (SIDI) engine has become a feasible alternative due to its better anti-knock characteristics and lower nano-particle emission level. There are a number of studies on the emission characteristics from SIDI engine fuelled with various ethanol contents. In general, increase of ethanol contents leaded to decrease of nano-particle discharge, but the other researches showed reversed result at a singular range of ethanol contents. This study focused on the engine combustion performance and nano-particle emission characteristics of SIDI engine fuelled with intermediate ethanol contents.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1178-1183
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• 2004

The purpose of this study was to investigate the influence of compression ratio on engine performance in a LPG(Liquefied Petroleum Gas) engine converted from a diesel engine. In ordor to determine the ideal compression ratio, a variable compression ratio 4-cylinder engine was developed. Retrofitting a diesel engine into a LPG engine is technically very complicated compared to a gasoline to LPG conversion. The cylinder head and the piston crown were modified to bum LPG in the engine. Compression ratios were increased from 8 to 10 in an increment of 0.5, the ignition timing was controlled to be at MBT(Minimum Spark Advance for Best Torque) for each case.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1264-1270
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• 2004

In this paper research on micro solid propellant thruster is reported. Micro solid propellant thruster has four basic components; micro combustion chamber, micro nozzle, solid propellant and micro igniter. In this research igniter, solid propellant and combustion chamber are focused. Micro igniter was fabricated through typical micromachining and the effect of geometry was evaluated. The characteristic of solid propellant was investigated to observe burning characteristic and to obtain burning velocity. Change of thrust force and the amount of energy loss following scale down at micro combustion chamber were estimated by numerical simulation based on empirical data and through the calculation normalized specific impulses were compared to figure out the efficiency of combustion chamber.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.225-230
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• 2017

Coal oil is widely used as a home heating fuel for portable and installed coal oil heaters. Today, Coal oil is widely used as fuel for jet engines and some rocket engines in several grades. This paper describes the performance characteristics according to the compression ratio of spark ignition engine fuelled with coal oil. As a result, the following knowledge is obtained: As the compression ratio is decreased, there is an increase in torque, indicated mean effective pressure (IMEP), heat release rate, and brake thermal efficiency. Higher compression ratio of the engine decreases the ignition delay period, combustion period, and cooling loss.

• 대한기계학회논문집
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• 제18권8호
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• pp.2194-2200
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• 1994

In an automotive spark ignition engine, it is important to form the proper mixture (air/fuel) on each driving condition for developing the stabilizing combustion and exhaust characteristics. Since most of supply fuel si attached on the inside wall of the intake manifold for unadequate nonuniformity of fuel distribution to each cylinder and mixture variation. Also it affects engine performance variation and causes noises and vibration. In this study, we verified the effect of the mixture variation which is caused by fuel liquid film in the intake manifold on combustion characteristics and engine performance.

• 한국자동차공학회논문집
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• 제1권1호
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• pp.80-89
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• 1993

Performance simulation for a Spark Ignition Wankel rotary Engine is presented in this paper. The volume of chamber at each eccentric shaft angle is evaluated by using geometric models of housing and rotor. A thermodynamic model which includes the first law of thermodynamics, combustion and convective heat transfer from chamber contents to surroundings is imployed. A thermochemical equilibrium model which considers 10 species(CO, $CO_2$, $O_2$, $H_2$, $H_2O$, OH, O, NO, $N_2$) in the burned gas region, is also employed. Four processes of gas exchange, compression, combustion and expansion are considered and the pressure, temperature and composition of chamber gas at each eccentric shaft angle in each process are computed in this performance simulation. This performance simulation must be useful for optimal design of Spark Ignition Wankel Rotray Engine with parametric study for various design parameters and operating conditions.

• 한국안전학회지
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• 제8권3호
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• pp.3-12
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• 1993

In reciprocating internal combustion engine, engine performance Is greatly affected by volumetric efficiency. For gas flow, the dynamic effects caused by the pressure pulsation have influence on the volumetric efficiency and correlate to the configuration and pipe length of intake-exhaust system. In this study, the analytic investigation of the unstudy flow In exhaust pipe has been carried out by using the method of characteristics to predict volumetric efficiency. In conculusion, it is possible to take account of the exhaust pipe tuning effect in predicting the engine performance, by the analytic solution of the unsteady flow in the pipes, and comparision of prediction with experimental datas show a good agreement on the pressure varision in the exhaust pipe which has Influence on the volumetric efficiency and performance of engine.