• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.98-104
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• 2011

The introduction of a diesel engine into the passenger car and light duty applications in the United States involves significant technical challenges for the automotive makers. This paper describes the SCR System optimization procedure for such a diesel engine application to meet Tier2 Bin5 emission regulation. A urea SCR system, a representative $NO_x$ reduction after-treatment technique, is applied to a 3.0 liter diesel engine. To achieve the maximum $NO_x$ reduction performance, the exhaust system layout was optimized using series of the computational fluid dynamics and the urea distribution uniformity test. Furthermore a comprehensive simulation model for the key factors influencing $NO_x$ reduction performance was developed and embedded in the Simulink/Matlab environment. This model was then applied to the urea SCR system and played a key role to shorten the time needed for SCR control parameter calibration. The potential of a urea SCR system for reducing diesel $NO_x$ emission is shown for FTP75 and US06 emission standard test cycle.

• Journal of the Korea Society for Simulation
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• v.14 no.4
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• pp.117-129
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• 2005

The climatic change convention is a matter of grave concern to the whole world. As a countermeasure against the climatic change convention, the Korean Government permits the sale of diesel passenger cars since 2005. In this paper, we analyse the effect of the sales permission of diesel passenger car as the countermeasure. The share, carbon emission, and pollutants emission of each type of passenger cars are analysed using system dynamics. The result is that the carbon emission is decreased by $5.5\%$ but the pollutants emission is increased by $5\%$. If the pollutants emission was dealt successfully with, the sales permission of diesel passenger cars would be a good countermeasure against the climatic change convention.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.3
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• pp.29-34
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• 2009

Diesel particulate filter (DPF) has been developed to optimize engine out emission, especially particulate matter (PM). One of the main important factors for developing the DPF is estimation of soot mass being accumulated inside the DPF. Evaluation of pressure drop over the DPF is a simple way to estimate the accumulated soot mass but its accuracy is known to be limited to certain vehicle operating conditions. The method to compensate drawback is adoption of integrating time history of the engine out PM and burning soot. Present study demonstrates current status of the soot estimation methods including the results from the engine test benches and vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.66-74
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• 2004

DPF technology has been considered as one of the most effective methods for reducing diesel particulate emission. PSA Peugeot Citroen introduced the DPF equipped diesel passenger car, Peugeot 607 HDI Sedan, in 2000 for the first time in the world, in which SiC filter, an oxidation catalyst, cerium based fuel born catalyst and post-injection technology were used for PM regeneration. In the present study, the characteristics of the Peugeot 607 DPF system were studied on chassis dynamometer and real road driving conditions. The change of emissions and fuel economy during 80,000km operation were also tested. Additionally, ash contents accumulated in the DPF filter was analyzed and particle size distributions was investigated after running of 80,000km.

• Journal of Energy Engineering
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• v.10 no.3
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• pp.177-182
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• 2001

This paper aims at evaluating HSDI diesel passenger cars introduction. The result of economic analysis after accounting for the life cycle cost per car shows a saving of 13,836 thousand won in fuel cost per diesel car assuming a life of 10 years and the annual travel distance of 20,000km. Assuming an average travel distance of 20,000km and a 10% increase in sales of diesel passenger car, the social benefit starts to accrue from the year 2002 and, in 2010, is estimated to be 154.1 billion won relative to the gasoline passenger car. The cumulative social benefit up to 2010 under the same assumptions is expected to reach 636.8 billion won.

• 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.

• Environmental Engineering Research
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• v.14 no.3
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• pp.180-185
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• 2009

Only limited information is available as regards to the exposure levels of naphthalene (polycyclic aromatic hydrocarbons, PAHs) and monocyclic aromatic hydrocarbons(MAHs) in the interiors of diesel-fueled passenger cars, while many studies investigated the exposure levels of various volatile organic compounds(VOCs) in the interiors of gasoline-fueled passenger cars or public buses. Present study was performed to supplement this deficiency by measuring naphthalene (as a representative of PAHs) and MAHs levels inside five diesel-fueled and five gasoline-fueled passenger cars while morning and evening commuting on real roadways. Each car was surveyed five times on different sampling days. The in-vehicle naphthalene levels were higher for the diesel-fueled cars as compared to gasoline-fueled cars, whereas the results were reversed for the in-vehicle MAH levels. The median cabin levels of diesel-fueled cars were 1.3, 7, 13, 4, and 6 ${\mu}g/m^3$ for naphthalene, benzene, toluene, ethyl benzene, and m,pxylene, respectively. With respect to gasoline-fueled cars, their respective levels were 0.7, 11, 21, 7, and 9 ${\mu}g/m^3$ . The median MAHs concentration ratios of gasoline-fueled cars to diesel-fueled cars ranged from 1.50 to 1.75, while the median naphthalene concentration ratio was estimated to be 0.54. In addition, there was no significant difference of both naphthalene and MAHs between the diesel-fueled cars, but the in-vehicle levels were significantly different between gasoline-fueled cars. The concentration levels of both naphthalene and MAHs were higher in the passenger cars than other non-industrial microenvironments. Consequently, it was confirmed that the cabins of both diesel-fueled and gasoline-fueled passenger cars are an important microenvironment associated with the exposure to naphthalene and MAHs.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.167-173
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• 2005

Thermal regeneration means burning-off and cleaning-up the particulate matters piled up in DPF(diesel particulate filter), and it requires both high temperature $(550\~600^{\circ}C)$ and appropriate concentration of oxygen at DPF entrance. However, it is not easy to satisfy such conditions because of the low temperature window of the HSDI(high speed direct injection) diesel engine(approximately $200\~350^{\circ}C$ at cycle). Therefore, this study is focused on the method to raise temperature using the trade-off relation between temperature, oxygen concentration, and the influence of many parameters of common rail injection system including post injection. After performing an optimal mapping of the common rail parameters for regeneration mode, the actual cleaning process during regeneration mode is investigated and evaluated the availability of the regeneration mode mapping through regenerating soot trapped in the DPF.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.680-685
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• 2006

The latest trend in the automotive industry demands the development of high stiffness car bodies and the securement of inter-system performance for low vibration and noise vehicles. This demand, however, conflicts with need for light weight design and greater fuel efficiency, thus raising the importance of optimization design to satisfy both developmental goals. We chose two European medium sedans, which has gasoline engine and diesel one, to elucidate the noise characteristics of diesel passenger cars, whose sales have been increasing in both Korea and Europe. In the present study a systematic experiment was conducted to analyze the noise characteristics in diesel cars. we made it possible for differentiating car management according to customer demand while allowing for improved commercial feasibility. it was possible to improve interior noise by 2 dB(A) on average sound pressure level. As a result, by 4% higher on articulation index(AI).

• Journal of the korean Society of Automotive Engineers
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• v.23 no.1
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• pp.34-42
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• 2001