• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.1-15
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• 1996

This study is concerned with the property changes(chemical and mechanical) of the used oil in diesel engine, which were sampled from a test engine with dynamometer and various cars. The properties of oil are TAN, viscosity, oxidation, ZDTP depletion factor and etc. Also the relation between the change of chemical and antiwear property of used oil was strongly related to ZDTP depletion factor as wall as the change of TAN(total acid number), sulfation and pentan unsoluble contents which were reated to the formation of protect film in sliding area. The oil used in pick-up(small) truck engine was deteriorated within the shortest distance than that of other cars. The antiwear property of used oil was decreased sharply as the running distance were over 5,000km. The oil used to mini bus was the least to deteriorate of properities for the funning distance.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2922-2927
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• 2008

The test of engine performance using the engine dynamometer needs technical researchers and facilities. A variety of CAE analysis programs and DoE(Design of Experiments) are used to analyze data efficiently instead of tests. The study got data from simulations of WAVE that used to model the SI engine to identify performance of engine. DoE makes it possible to know effectiveness of factors for power, BSFC, volume efficiency and find optimum condition in each factor through minimizing number of experiments. CA50 has effect on power and BSFC as volume efficiency is related with cylinder liner temperature and heat coefficients. The final result in DoE could be identified of consistency above 98% after substituting the data to WAVE.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.899-905
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• 2000

The characteristics of air flow and engine performance with swirl ratio variance of intake port In a turbocharged DI diesel engine was studied in this paper. The intake port flow is important factor which have influence on the engine performance and exhaust emission because the properties in the injected fuel depend on the combustion characteristics. The swirl ratio for ports was modified by hand-working and measured by impulse swirl meter. For the effects on performance and emission, the brake torque and brake specific fuel consumption were measured by engine dynamometer and NOx, smoke were measured by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased. And as the swirl ratio is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by optimizing the main parameters; the swirl ratio of intake port, injection timing and compression ratio.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.5-10
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• 2005

The effect of ultrasonic energy for diesel fuel and blend oil has been revealed in this paper. The experimental setup consisted of a high speed diesel engine with 4 cylinder, dynamometer and ultrasonic fuel feeding system. Ultrasonic energy was added to diesel fuel and blend oil, which is a blend of diesel fuel and rape-seed oil. As engine speed was changed, engine torque and power, brake specific fuel consumption and thermal efficiency were measured in detail. As the results, by adding ultrasonic energy to diesel fuel and blend oil, the engine performance was improved in range of the experiment. The effect of improvement on brake specific fuel consumption and thermal efficiency for blend oil is higher than that for diesel fuel. When ultrasonic energy was added to diesel fuel or blend oil, a rise in engine torque for diesel fuel was higher than that for blend oil, but the effect of ultrasonic energy was small. From these results, it may be desirable to add ultrasonic energy to blend oil for the use of blend oil to diesel engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.6
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• pp.175-182
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• 1997

The purpose of this study is to investigate the effects of intake manifold shapes to improve the engine performance in a 3-cylinder LPG engine with a closed loop fuel supply system. To know the flow resistance of intake manifolds with shape, the intake negative pressure of each runner in intake manifolds were measured by using the digital pressure meter at each driving condition. And, the engine torque and power have been measured with an engine dynamometer while adjusting the optimal fuel consumption ratio with a solenoid driver. As 속 results form this experiment, the torque characteris- tics were more improved with the plenum chamber(B type intake manifold) than with the banana type(A type intake manifold). The torque characteristics were improved at mid-engine speed(rpm) range as the inner diameter of the intake manifold became smaller. And also the optimum volume among the examined plenum chamber volume was 0.74 times(590cc) the displacement of the test engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.35-43
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• 2014

The automobile industry requires technological innovations to reduce fuel consumption with the public interest in environmental conservation in recent years. Thus, the hybrid system is applied not only to passenger cars but also commercial vehicles. The purpose of this paper is to develop engine ECU_ILS to develop commercial hybrid vehicles. In order to develop the engine and vehicle, the dynamometer and exhaust gas analyzer is needed. However, a lot of time and cost are required. In contrast, the model-based development environment that can be applied to a variety of test conditions can reduce development time. Therefore, a HILS system environment that can consider the behavior of actual vehicles for evaluation of the control logic, fuel consumption and exhaust gas is required. This engine ECU_ILS system was developed in this study, can analyze parameter such as the fuel injection rate, fuel injection time, fuel consumption and exhaust gas like the actual vehicle test using map data. Also, this system is expected to be able to analyze the characteristic of vehicle behavior and the development of peripheral device in relation to engine and vehicles. This HILS system can be used to develop control strategies of commercial hybrid vehicle systems in the future.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.2
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• pp.34-43
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• 1992

The purpose of this study is to consider the performance and exhaust characteristics in the practical engine according to the cooling water temperature change of engine and to set up the optimum cooling condition and to obtain the optimum operating condition of thermostat in the cooling system. In order to accomplish the purpose of this study, authors have used the following procedure. 1. This study is to investigate the influence of the cooling water temperature on the engine performance and the exhaust gas, authors regulated the cooling water temperature by using the special closing circuit and measured the concentration of exhaust gas by using the exhaust gas measuring system in the exhaust pipe. 2. This study carried out the experiment by regulating the opening degree of throttle valve and engine speed in the dynamometer and by changing the cooling water temperature, at the same time kept air-fuel ratio constant and made the spark ignition time MBT(Minimum spark advance for Best Torque) 3. This study measured the cooling water temperature by using the K-type thermocouple centring around the easy over-heated parts and by installing a special closing circuit. Therefore, in this study, authors intend to examine the influence of the cooling water temperature on the engine performance, exhaust gas and present the basic materials needed in the engine design including the optimum operating time control system for the cooling water temperature.

• Journal of ILASS-Korea
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• v.14 no.1
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• pp.34-38
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• 2009

This paper presents the pulsation of carburetor inlet and outlet pressure of a small SI gasoline engine. The engine used in this paper is a 23cc, single cylinder, diaphragm carburetor, two-stroke, air-cooled for brush cutter. The rpm and pressure wave pulsation at the inlet and the outlet of carburetor were measured and analysed for the understand of the internal air flow into the barrel on the diaphragm carburetor. These data should be used for the development of the duel fuel injection system for gasoline and LPG. The results showed that the carburetor inlet pressure variations were very steady, but the pressure variations at carburetor outlet were very sensitive to the pressure variation into the crank case and were to similar independently to the engine speed on partial opened throttle conditions. According to increasing engine speed, the pressure waves started to come out and be developed after closing the intake port of the engine at carburetor outlet. Reverse flow occurred on the WOT (wide open throttle) condition.

• Journal of Biosystems Engineering
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• v.18 no.4
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• pp.305-316
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• 1993

Fuel efficiency in tractor operations dep6nds on the selection of transmission gears and upon the engine being operated at or near maximum torque much of time. The objective of this study was to develop automatic control systems for tractor transmission ratio and governor setting so that the engine is operated at or near maximum torque as much of time as possible. An indoor test unit, which can be used to simulate tractor operation, was built in order to investigate the system design parameters and test the performance of the control system designed. The test-unit consists of engine, gear-type transmission, dynamometer, and control systems for transmission ratio and engine speed. Governor setting lever was controlled by a step motor, and the clutch and transmission levers were controlled by hydraulic cylinders and solenoid valves. The control systems showed good time responses which are assumed to be suitable for optimal tractor operation. The time required for shifting gears from clutch disengagement to engagement was about 1 second, which is almost the same as that for manual shift. And the settling time for engine speed control system was about 5 to 6 seconds.

• Journal of Energy Engineering
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• v.17 no.4
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• pp.198-203
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• 2008

The objective of the research was to study the effects of Miller cycle in a modified using diesel engine. The engine was dedicated to natural gas usage by modifying pistons, fuel system and ignition systems. The engine was installed on a dynamometer and attached with various sensors and controllers. Intake valve timing, engine speed, load, injection timing and ignition timing are main parameters. The results of engine performances and emissions are present in form of graphs. Miller Cycle without supercharging can increase brake thermal efficiency and reduce brake specific fuel consumption. The injection timing must be synchronous with valve timing, speed and load to control the performances, emissions and knock margin. Throughout these tested speeds, original camshaft is recommended to obtain high volumetric efficiency. Retard ignition timing can reduce $NO_x$ emissions while maintaining high efficiency.