• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.423-424
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• 2002

Amount of regulated emissions (CO, $NO_x$, HC), and emissions of some groups of organic substances (volatile hydrocarbons, polyaromatics, and aldehydes) were measured in the standard ECE 83 test on spark ignition engine of a passenger car. The influence of the engine oil composition (mineral or fully synthetic) was examined. For both engine oils, exhaust emissions were measured with fresh oil as well as used oil at the end of the oil drain interval. Unleaded petrol and CNG were used as fuels in all experiments performed. The main conclusion made from the tests is that polyaromatics is the only part of th ε exhaust emissions that was influenced with the nature of the engine oil. Effect on the other components of emissions (aldehydes and VOC) was negligible. Emissions of polyaromatics were almost twice higher for fresh mineral as for fresh fully synthetic oil. The amount of polyaromatics in the exhaust emissions increased slightly with mileage for fully synthetic and substantially more for mineral engine oil.

• The Journal of the Acoustical Society of Korea
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• v.21 no.1E
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• pp.42-48
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• 2002

In this paper, a computer simulation method is presented far the dynamic analysis of a hydraulic engine mount system. The hydraulic engine mount system controls the damping characteristics using the viscosity of fluid flow. The complex stiffnesses of the main rubber for the hydraulic engine mount system are computed using a finite element analysis. The equations of motion considering the parameters of the hydraulic engine mount system are derived. To investigate the effects of the hydraulic engine mount system, the computer simulation running over a typical rough road is carried out using a vehicle dynamic model. These results are compared with those of the conventional rubber mount system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.3
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• pp.324-329
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• 2004

As a new concept in engines and a power source for future automotive applications, the HCCI(Homogeneous Charge Compression Ignition) engine has been introduced. Essentially a combination of spark ignition and compression ignition engines, the HCCI engine exhibits low NO$_x$ and PM emissions as well as high efficiency under part load. In this research, a 4 cylinder diesel engine was converted into a HCCI engine, and propane was used as the fuel. The main parameters for this research are fuel flow rate and the temperature of the intake manifold, and the effects of such on a HCCI engine's performance and exhaust was investigated.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.107-113
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• 2002

LPG has been well known as a clean alternative fuel for vehicles. Recently, several LPG engines for heavy duty vehicles have been developed, which can replace some diesel engines that are one of the main sources for air pollution in the urban area. Because cylinder bore of heavy duty LPG engine is larger than that of gasoline, the study of knock characteristics of LPG engine are needed. In this study, the knock characteristics were investigated with various engine speed, air excess ratios and LPG fuel compositions. Experimental results indicated that the Knock occurrence probability decreases with increasing engine speed and propane fraction of fuel. The Knock occurrence probability is highest at excess air ratio of 1 and decreases as the mixture strength became leaner.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.297-300
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• 2005

This paper presents vibration control of an engine mount for a passenger vehicle utilizing ER fluid and piezoelectric actuator. The proposed engine mount can be isolated the vibration of wide frequency range with many types of amplitude. The main function of ER fluid is to attenuate vibration for low frequency with large amplitude, while the piezoelectric actuator is activated in hish frequency range with small amplitude. A mathematical model of the engine mount is derived using Hydraulic model and mechanical model. After formulating the governing equation of motion, then field-dependent dynamic stiffness of the engine mount is evaluated for various engine speed and excitation amplitude conditions. Then robust controller is designed to attenuate vibration of wide range frequency component. Computer simulation is undertaken in order to evaluate the vibration control performance such as transmissibility magnitude in frequency domains.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.854-861
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• 1998

The demand of LNG as a cheap and clean energy which does not cause an environmental problem has sharply been increased in Korea. In general LNG is stored in a cargo tank specially designed as a liquid state below $-162^{\circ}C$. The main engine of a LNG carrier is generally a steam boiler because LNG is a highly flammable fluid with the possibility of explosion. The main engine of a cargo ship has to be capable of the propulsion load and various auxiliary loads for the safe navigation since it is the primary energy source. Therefore the evaluation of a main boiler's energy capacity is a key design point in the planning of LNG carrier's construction. This research is to develop the computational program for the analysis of steam boiler Heat balance for LNG carrier.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.134-140
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• 2015

A control program of an engine control module (ECM) was developed, and its control performance was verified on a 750Ps marine diesel engine. The control method was designed for an engine rotational speed control system. For ECM hardware, the commercial rapid control prototype (RCP) ECM was used. The programming tool for control algorithm development was the MatLab/Simulink. The main control algorithm assembled many control models as engine cranking, run, and stall. Each model has sub-models to input/output control signals. The target engine speed was input signal from a speed control lever, and control output signal of the ECM was sent to the unit-injectors for fuel injection. The engine test was performed under various conditions of engine rotational speeds and dynamometer loads. The test results show that the control function of the ECM is suitable for electrical marine diesel engines.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.1-11
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• 2000

This study is aimed to develop a proto-type LPG engine for medium-duty commercial vehicles in order to substitute for conventional diesel engine. Recently, it is recognized that diesel engines are main cause for smoke pollution in urban site. So, it is expected to reduce this environmental emission by developing and substituting LPG engine which has the advantage of practical use in a short development period in aspects of infrastructures. For that, after analysing the specifications and performance characteristics of a base diesel engine, parts of combustion chamber, intake system, fuel supply and ignition systems suitable for LPG combustion were re-designed and manufactured. And and engine controller for fuel supply and ignition distributions was matched by feedback mapping based on the speed-load conditions. The torque and power of LPG engine were increased by 6∼12% on the overall driving conditions compared to the base diesel engine, and fuel consumption rate marked the similar level based on the fuel price. Exhaust emissions such as THC, CO, NOx recorded the same order with conventional LPG engine for passenger car.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.138-143
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• 2006

Modification of injector, oil ring tension reduction and oil pump rotor re-matching with optimization of relevant engine control parameters could drive fuel consumption reduction of HSDI diesel engine. A 5 holes injector was replaced with a 6 holes with smaller nozzle hole diameter and 1.5 k factor, and evaluated in a view of fuel economy and emission trade-offs. With introducing smaller nozzle hole diameter injector, PM(Particulate Matter) was drastically decreased for low engine load and low engine rpm. Modification of oil pump and oil ring was to reduce mechanical friction and be proved to better fuel economy. Optimization of engine operating conditions was a great help for the low fuel consumption. Influence of the engine operating parameters· including pilot quantity, pilot interval, air mass and main injection timing on fuel economy, smoke and NOx has been evaluated with 14 points extracted from NEDC(New European Driving Cycle) cycle. The fuel consumption was proved to $7\%$ improvement on an engine bench and $3.7\%$ with a vehicle.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.109-113
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• 2007

Yacht have an high powered main engine relatively light hull, so the noise generated from the engine have a bad influence upon the crew and passenger. Recently, cruise yacht is made an attempt by domestic production skill, however the insulation skill of the noise made by the main engine is not satisfy the real purchasing power of the buyer. Like this, yacht cabin's noise level is becoming the barometer to decide the purchase. the method to insufficient. However, if we use the skill of the monitoring equipment and the genetic algorithm system, the circumference of the main engine can be enclosed by an high quality absorbtion wall and the noise levels of the cabins are improved. In this study, the sound absorbtion barrier is experimentally researched by change the volume and the length of the neck for the Helmholtz resonator as the resonator can absorb the noise effectively.