• Corrosion Science and Technology
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• v.18 no.1
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• pp.16-23
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• 2019

Steels for automotive fuel tank require unique properties such as corrosion resistance for fuel, welding for joining, forming for press, and painting for exterior. Recently, automakers have been requiring excellent seam weldable steels to enhance manufacturing productivity of fuel tank. Thus, POSCO developed a new type of functional steels coated with nano-composite thin layer on Zn-Ni plating steels. The nano-composite coating solution was prepared by mechanical fine dispersion of solutions consisting of polymeric resin and nano-composite materials in aqueous media. The composite solution was coated on the plating steel surface by using roll coater and cured through induction furnace. These new developed plating steels were evaluated for quality performances such as seam and spot weldability, press formability, and corrosion resistance. These new functional steels coated with nano-composite layer exhibited excellent seam weldability and press formability. Detailed discussion of coating solution and experimental results suggest that nano-sized composite dispersion as coating layer plays a key role in enhancing the quality performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.107-114
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• 2009

A Common-Rail Direct Injection (CRDI) system for high speed diesel engines was developed to meet reductions of noise and vibration, emission regulations. High pressure in the common rail with electric control allows the fuel quantity and injection timing to be optimized and controlled throughout a wide range of engine velocity and load conditions. In this study, CRDI system analysis model which includes fuel and mechanical systems was developed using commercial software, AMESim in order to predict characteristics for various fuel injection components. The parameter sensitivity analysis such as throttle size, injection rate, plunger displacement, supply pressure of fuel injection for system design are carried out.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.137-141
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• 2007

The startup behaviour of PEM fuel cells at subfreeze zero is one of the most challenging tasks to be solved before PEM fuel cell vehicle is commercialized. Automotive companies are trying to increase cold statup capability of fuel cell. In this study, we found out the design factor of the stack to increase cold startup capability using 4kW stack and then cold startup test was performed at the various shutdown condition and the various current. In order to test the cold startup possibility and capability in vehicle, we installed 80kW stack in the vehicle and this 80kW fuel cell vehicle was housed in an environmental chamber to investigate the characteristics of cold startup and driving. We found that it is possible for fuel cell vehicle with 80kW stack to self-heated cold startup and drive at $-15^{\circ}C$.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.4
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• pp.72-79
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• 1994

In an automotive spark ignition, 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 is attached on the inside wall of the intake manifold for unadequate atomization by fuel injection system, it brings a bad effect on combustion and exhaust caused by 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 an intake manifold on combustion characteristics and engine performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.123-131
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• 1999

Natural gas is one of the most promising alternative fuels for automotive vehicles. However, natural gas varies in compositional between the originating fields and may be further modified due to processing and additional mixing. These variations are known to affect engine performance and emissions through changes in fuel metering and combustion characteristics. In the present study, the effect of gas compositions on vehicle performance such as fuel economy, driveability and exhaust emissions was examined. Analysis are made of using 3 types of NGVs which were made by automakers and 6 different fuels which are selected in consideration of the variation in fuel composition on the worldwide market. The results may be utilized to develop natural gas natural gas engine in automaekrs and/or to establish the fuel standard in the refueling stations.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.20-27
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• 2003

In this paper, the fuel transport characteristics during transient condition was studied by using a Fast Response Flame Ionization Detector(FRFID). The quantitative measurement method for the inducted fuel mass into cylinder is studied. The inducted fuel mass into the cylinder was estimated by using calculated air-fuel ratio by hydrocarbon concentration of cylinder and air flow model. In order to estimate the transportation of injected fuel from the intake port into cylinder, the wall wetting fuel model was used. The two coefficient $\alpha$,$\beta$) of the wall-wetting fuel model was determined from the measured fuel mass that was inducted into the cylinder at the first cycle after injection cut-off To reduce an air/fuel ratio fluctuation during rapid throttle opening, the appropriate fuel injection rate was obtain from the wall wetting model with empirical coefficients. Result of air/fuel ratio control, air/fuel excursion was reduced.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.74-80
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• 2009

The objective of this paper was to investigate the slip rate and the slip frequency number of damper clutch of torque converter in 2.4L passenger vehicle with 5-speed A/T and analyze the effect of slip control and control strategy on driving characteristics and the fuel economy. The newly developed torque converter with the more durable wet friction material and the slip-controlled damper clutch system, the DCC system, was installed, which was easily compatible and amendable of the lock-up clutch of the base system. The vehicle has been tested on the fuel economy modes such as FTP-75, HWFET and NEDC (ECE15+EUDC) driving cycle at chassis dynamometer. The DCC mode (II), of which the control strategy had both the lock-up and the slip-controlled clutch, and the DCC mode (I) with full slip-controlled clutch were compared with the base system with only the lock-up clutch. As the research result, comparison to base system, the fuel consumption of the vehicle with the DCC control (II) was effectively improved by 6.6% and 7.7% on FTP-75 and NEDC mode.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.112-119
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• 2010

Recently, as the matters of environmental pollution, the energy exhaustion and alternative energy source have become more important issues, around industrial countries and the effort to improve fuel consumption is progressed continuously for decrease of air pollution. In an effort to improve fuel consumption for passenger cars, the study of DLC (Diamond Like Carbon) coating which is widely known to good wear characteristics come to the forefront. Therefore, in present study, it was investigated to the influence of DLC coating layer for wear characteristics with the piston ring material and then suggested to the development process for advanced automotive engine parts that showed improved wear characteristics. From these results, Finally, it will be contributed to improve the fuel consumption for passenger vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.109-114
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• 2008

An improvement of vehicle fuel economy is one of the most important topic in automotive engineering. Lots of engineers make efforts to achieve 1% of fuel economy improvement. Engine friction is an important factor influencing vehicle fuel economy. This paper focuses on effect of engine friction on vehicle fuel economy during warm-up. A computer simulation is one of the powerful tools in automotive engineering field. Recently Simulation is attempting to virtual experiment not using expensive instruments. It is possible to presuppose fuel economy by changing the characteristic of accessories using CRUISE(vehicle simulation software). In this paper, fuel consumption at each part of the vehicle is analyzed by both of experiment and simulation. The results of fuel economy analysis on experiment substitute for Cruise to calculate fuel economy. The simulation data such as engine speed, brake torque, shift pattern, vehicle speed, fuel consumption level is well correlated to experiment data. In this paper, the change of warm-up time, faster or slower, through simulation is performed. As a result of the fast warm-up, fuel economy is improved up to 1.7%.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.35-40
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• 2007

The gaseous fuel injection (GFI) type in LPG fuel supply system has more advantage than the liquified fuel injection type from the viewpoint of durability and cost reduction. But in GFI system, to control pressure and temperature of gaseous fuel is needed to get precision fuel metering for the compressible characteristic of gaseous fuel. In this study, the effects of pressure and temperature on the fuel metering was simulated by commercial flow network analysis package, Flowmaster. And the fuel composition effects on the fuel metering were also studied to figure out the fuel metering characteristics.