• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.191-198
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• 1998

In this study, the effects of water vapor in inlet air, spark advance and fuel type in the spark ignition engine were investigated through the experiments of combustion and flame arriving pattern analysis using ionization probe. The results of flame propagation experiment using ionization probe show that the flame which ignited from spark plug located at the center of the combustion chamber propagated faster in exhaust side than in intake side due to the mixture flow motion inducted into combustion chamber from intake tumble port at all conditions. And as the partial vapor pressure increased, the flame propagation became slower in all direction. Especially effects were greater for intake side than the exhaust side.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.4
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• pp.41-46
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• 1983

The influence of inlet air humidity on the flame velocity and combustion of the spark ignition engine were described experimentally by means of the flame velocity measuring apparatus using ion-current. The flame velocity are greatly influenced air fuel ratio and engine speed, and linealy decrease according to the increasing of inlet air humidity. The flame travell curve is very similar to the rate of mass burned and combustion progressive is estimated mostly by only the rate of mass burned curve. The decreasing of the mean flame velocity is about 0.4m/s for increasing of 0.001 specific humidity and we think the reason is mainly decreasing of thermal conductivity.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.1-8
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• 2000

A new method of knock detection in SI engines, using a change of ion concentration in the combustion chamber, was developed. In order to measure in-cylinder ionization current, ionization probes were installed at spark plug and cylinder head of production engine. It was found that the electric current generated by ionized gas in core burned gas region of knocking cycle is between 2 and 10 times larger than that of normal cycle, because the burned gas temperature which is the dominant parameter of a change of ion concentration increases. However, a change of ionization current in boundary region of burned gas is relatively weak. Hence a change of ion concentration in core burned gas region can be used for knock detection.

• Advances in materials Research
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• v.4 no.2
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• pp.63-76
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• 2015

The energy crisis involving depletion of fossil fuel resource is not the sole driving force for developing renewable energy technologies. Another driving force is the ever increasing concerns on the air quality of our planet, associated with the continuous and dramatic increase of the concentration of greenhouse gas (mainly carbon dioxide) emissions. The internal combustion engine is a major source of distributed $CO_2$ emissions caused by combustion of gasoline derived largely from fossil fuel. Another major source of $CO_2$ is the combustion of fossil fuels to produce electricity. New technologies for generating electricity from sources that do not emit $CO_2$, such as water, solar, wind, and nuclear, together with the advent of plug-in hybrid electric vehicles (PHEV) and even all-electric vehicles (EVs), offer the potential of alleviating our present problem. Therefore, the relevant technologies in $LiFePO_4$ as cathode material for Li-ion batteries suitable to the friendly environment are reviewed aim to provide the vital information about the growing field for energies to minimize the potential environmental risks.

• 한국디지털정책학회:학술대회논문집
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• 2007.06a
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• pp.325-332
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• 2007

The purpose of this study is to get a politic advanced idea to operate a pro-environment based u-city through the overcome problems on the construction policy for the even areal distribution, and the development for the model structure of the high level. Advanced pro-environmental ubiquitous urban construction becomes an example of the practical level linked by the national agenda as uKorea policy. The Idea of the national land informal ion systems transforms to enhance or to guide the national strategic industry to implement balanced development as grand objectives of the national land due to the factor that 'the economic development 5 years plan' altered to 'the national land 5 years plan'. Therefore, ubiquitous echo city construct ion becomes realized as static spatial informal ion construct ion and dynamic mobile based ubiquitous lives operable by the information infrastructure and IT839 policy items operation. For the synergy effects through this task, it requires a strong empowerment of the information industries and a new growing core engine of the national economy through the policy of the mutual satisfaction on the spat io-temporal information and the pro-environment information systems.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.2
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• pp.69-78
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• 1982

The purpose of this study is to investigate the flame propagation phenomenon in the combustion chamber of spark-ignition gasoline engine for the idling condition. by means of four ion probes located through the cylinder head, the time intervals for the flame to arrive at the respective probes are read on th visicorder char. As results, the flame is considered to initiate after some ignition delay and to propagate through the central space of combustion chamber with rather constant speed on the order of 25m/sec, and thereafter to be slowed down approaching the wall. Additionally, the retardation of flame in the wall boundary layer could be inferred. The maximum pressure is developed when the flame nearly touches the wall diagonal to the spark plug. And some features of flame propagation are elucidate.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.2
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• pp.252-257
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• 2011

Magnesium thin films for marine engine parts such as the engine block and the cylinder head cover etc. were prepared on the magnesium alloy(AZ91D) substrate by Thermo-electron activated Ion-plating method. The influence of gas pressure and substrate bias voltages on the crystal orientation and morphology of the films was investigated with X-ray diffraction and field emission scanning electron microscope(FE-SEM), respectively. Moreover, the effect of crystal orientation and morphology of the magnesium films on the its hardness property was investigated as well. From the results, the hardness of the films was increased in Ar gas pressure due to the grain boundary strengthening and occlusion effects.

• Journal of Energy Engineering
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• v.19 no.1
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• pp.39-50
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• 2010

Hybrid Electric Vehicle(HEV) and Plug-in Hybrid Electric Vehicle(PHEV) will replace Conventional Gasolene Engine Vehicle at a rapid rate to eliminate emission gases and improve fuel economy. This review describes Fuzzy Logic Control strategy and Optimization for Parallel Hybrid Electric Vehicle. Recent progress on Electric Motor and Li-ion Battery for HEV and PHEV are given. Analysis on competitiveness of Korean HEV and PHEV technology based on the number of papers published and patents registered are also performed.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.335-343
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• 2003

In the electrode fabrication of unit cell, it was ascertained that electrochemical characteristics were greatly increased with 90 wt.% of BP-20, 5 wt.% of Super P and 5 wt.% of mixed binder [P(VdF-co-HFP) : PVP =7 : 3] The self-discharge of unit cell showed that diffusion process was controlled by the ion concentration difference of initial electrolyte due to the characteristics of Electric Double Layer Capacitor (EDLC) charged by ion adsorption in the beginning, but this by current leakage through the double-layer at the electrode/electrolyte interface had a minor effect and voltages of curves were remained constant regardless of electrode material. The electrochemical characteristics of 2.3 V/3,000 F grade EDLC were as follows: 0.35 m of DC-ESR (100 A discharge), 0.14 mof AC-ESR (AC amplitude 100 mV), 2.80 Wh/kg (3.73 Wh/L) of energy density and 4.64 kW /kg (6.19 kW/L) of power density. Power output was compatible with electric vehicle applications, uninterrupted power supply and engine starter, in due consideration of Ragone relations.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.631-636
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• 2018

This paper proposed an optimal operation strategy for a hybrid energy storage system (HESS) with a lithium-ion battery and lead-acid battery for mild hybrid electric vehicles (mild HEVs). The proposed mild HEV system is targeted to mount the electric motor and the battery to a conventional internal combustion engine vehicle. Because the proposed mild HEV includes the motor and energy storage device of small capacity, the system focuses on low system cost and small size. To overcome these limitations, it is necessary to use a lead acid battery which is used for a vehicle. Thus, it is possible to use more energy using HESS with a lithium battery and a lead storage battery. The HESS, which combines the lithium-ion battery and the secondary battery in parallel, can achieve better performance by using the two types of energy storage systems with different characteristics. However, the system requires an operation strategy because accurate and selective control of the batteries for each situation is necessary. In this paper, an optimal operation strategy is proposed considering characteristics of each energy storage system, state-of-charge (SOC), bidirectional converters, the desired output power, and driving conditions in the mild HEV system. The performance of the proposed system is evaluated through several case studies with respect to energy capacity, SOC, battery characteristic, and system efficiency.