• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.174-179
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• 2005

In automotive engineering, the brand sound is one of the important advantage strategy in a car company. For the design of brand sound, the selection of descriptive word for a car sound is one of major works in automotive sound quality research. In paper, booming sound and rumbling sound, which are professional words used by NVH engineers are used for the design of brand sound. We employed sound metrics which are the subjective parameter used in psychoacoustics. According to most research results, the relationship between subjective evaluations and sound metrics has nonlinear characteristics and is very complex. In order to link these subjective evaluations to sound metrics, the artificial neural network technology has been applied to two-dimensional sound quality index for a passenger car. These indexes is used for 46 passenger cars, which are samples of famous cars in the world. Also the preference in car sounds is evaluated by the trained NVH engineers. We coupled this preference with booming and rumbling sounds by using artificial neural network. In future, the two -dimensional sound index and preference index are very useful fur the development of brand sound in passenger cars.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.3
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• pp.243-250
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• 2009

The clutch with torsional damper is installed on a passenger car with manual transmission, which not only transmits the power generated by engine to the transmission but also absorbs the shock and vibration from the engine. The torsional damper in the clutch dissipates the torsional vibration energy and eliminates the resonance in the driveline but high damping in the damper causes the increase of the vibration level which is against the comfort and durability. In this study, a dynamic model for the passenger car driveline with manual transmission was developed to investigate the vibration and the effects of characteristics of the driveline. With the dynamic model, the vibration characteristics of driveline were examined by the mode analysis and driving simulation, and the effects of hysteresis torque and spring constant were investigated. The vehicle tests with prototype torsional dampers were preformed and the test results showed good agreements with the simulation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.5 s.110
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• pp.457-469
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• 2006

In automotive engineering, the brand sound is one of the important advantage strategies in a car company. For the design of brand sound, the selection of descriptive word for a car sound is one of major works in automotive sound quality research. In this paper, booming and rumbling sound, which are professional words used by sound and vibration engineers are used for the design of brand sound. We employed sound quality metrics, which are used in the psychoacoustics. By most research results, the relationship between subjective evaluations and sound quality metrics has nonlinear characteristics. In order to correlate these subjective evaluations with sound quality metrics, the artificial neural network technology has been applied to two-dimensional sound quality index for a passenger car. These indexes are used for 46 passenger cars, which are samples of the famous cars around the world. Also a preference evaluation for car sound was carried out by sound and vibration engineers. We coupled this preference with booming and rumbling sounds by using artificial neural network. In future, the two dimensional sound and preference index will be very useful to develop brand sound in passenger cars.

• 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.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.107-113
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• 2007

This research addressed the problem of describing how the operating characteristics of passenger car and large vehicle differ qualitatively and quantitatively through the analysis of field survey data. A formulation that estimates passenger car equivalents used in this paper is derived by microscopic headway method. Regression analysis was used to focus on the effect of vehicle type on intervehicular spacings and the modeling technique for the statistical analysis was detailed.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.74-87
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• 2015

A numerical parametric study has been accomplished to figure out the effect of grille shape built in a small passenger car on the aerodynamic performance such as drag and mass flow rate through CRFM(Condenser Radiator Fan Module). Three grille opening parameters and three grille mesh parameters are selected and adopted to a simple shape passenger car model. This research will provide a design guideline for grille opening geometry and mesh shape in the grille. FLUENT, which is very well known commercial code, hires k-${\epsilon}$ turbulence model at the driving speed of 110km/h with moving wall boundary condition. A porous media condition is prepared to estimate the pressure drop amount through CRFM parts.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.393-399
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• 2008

A Study has been conducted on the characteristics of temperature variation depending on passenger number that is measured in Bundang Line(From Sunleng To Bojong). As a basic study, the air quality of passenger room for the electric rail car is evaluated. Although ISO7730 recommends that the height of measuring points for the heat environment is to set at 0.1m, 0.6m, 1.1m and 1.7m respectively, temperature are measured at two points at 1.1m and 1.7m because of the difficulty to measure temperature of 0.1m height in rush hour. We compared the results of temperature variations between two stations in rush hour(07:56-08:41). In general, the capacity of a passenger car is designed for 160 persons, but over 280 persons often board on electric rail in rush hour. The temperature of room is adjusted from $22^{\circ}C$ to $24^{\circ}C$, but it is measured from $26^{\circ}C$ to $28^{\circ}C$ on average. Therefore, it shows that there are difference between the set temperature and measured one. This article suggests the ways of the time adjusting and air-conditioning to satisfy customer's demand and the guide line to design the optimum capacity of air-conditioner of the new electric rail car which will be introduced in the near future.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.79-83
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• 2006

The present low speed crash regulations and RCAR test for insurance estimate do not tend to reflect car crash occurred on a road. Therefore, car makers are trying to readjust test standard be similar to a real situation. Passenger cars and SUV vehicles on the market will be subject to this study for car to car crash. In addition, we will discuss improvement of test methods for a low speed crash and direction of bumper design by performing this impact analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.1-8
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• 2014

Safety performance of a new car is evaluated through USNCAP and their results in the star rating are provided to the consumers. It is very important to obtain high score of USNCAP to appeal their performance to consumers. Therefore the car companies have made the effort to improve their car safety performance. These efforts should satisfy the demand not only to get high score but also to pass the FMVSS, NHTSA regulations on safety. Huge numbers of car crash tests have been conducted on these bases by car companies. However physical tests spend too much cost and time, as an alternative way, the simulation on the car crash could be a solution to reduce the cost and time. Therefore the simulations have been widely conducted in car industry and various researches on this have been reported. In this study, restraint system had been optimized to minimize the injury of female passenger. Belted $5^{th}%ile$ female frontal crash test was selected from various test methods of USNCAP for the study. Initial velocity of the test was 56km/h. The combination injury probability of USNCAP was selected as an objective function and the injury limit value, which was defined in FMVSS, was set to an optimization constraint. Many researches that were similar to this study had been conducted, however most of them had limitation that interaction between airbag and safety belt had not been considered. Contrary to these researches, the interaction was considered in this study.