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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Automotive Engineers
Editor in Chief :
Volume & Issues
Volume 9, Issue 6 - Nov 2001
Volume 9, Issue 5 - Sep 2001
Volume 9, Issue 4 - Jul 2001
Volume 9, Issue 3 - May 2001
Volume 9, Issue 2 - May 2001
Volume 9, Issue 1 - Jan 2001
Selecting the target year
The Experimental Study of Early Fuel Evaporation Characteristics Gasoline Engine Using Glow-Plug
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 1~10
In order to reduce hydrocarbon emissions of spark ignition engine, it is important not only to improve catalyst conversion efficiency but also to reduce direct engine out hydrocarbon emissions, during cold starting and warm up process. Tjerefore many researchers have been attracted to develop an early fuel evaporator (EFE) by introducing a ceramic heater for a solution of engine out hydrocarbon emissions in SI engine. But, the performance of the EFE in MPI engine to reduce the exhaust emissions and to improve the cold startability has nat been clarified yet. The purpose of this study is to evaluate the feasibility of a glow plug for EFE.
Influence of SAC Shape on Injection Characteristics and Spray
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 11~18
To clarify the influence of SAC shape of hole-type diesel nozzle on injection characteristics and spray patterns, the injection rate of three nozzle types(standard SAC nozzle, Needle-cut VCO nozzle and VCO nozzle) were measured by Zeuch's method and pictures of the sprays were taken by CCD camera. As the pump speed became higher, the injection characteristics of the three nozzles were different. Injection rate and perssure curves at the high pressure pipe in Needle-cut VCO nozzle were much more similar to the VCO nozzle than those of the SAC nozzle. When the needle was at pre-lift period for all speeds, the spray of the Needle-cut VCO nozzle showed almost the same shape as the SAC type nozzle. There was no differense in spray pattern at the needle full-lift periods.
In-Cylinder Fuel Behavior According to Fuel Injection Timing and Port Characteristics in an SI Engine : Part I-Without Swirl
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 19~27
This paper is the first of 3 companion papers which investigate axial stratification process. In-cylinder fuel behavior has been investigated in the port injected SI engine by visualization for the purpose of understanding stratification. Planar laser light sheet from an Nd:YAG laser has been illuminated through the transparent quartz cylinder of the single cylinder optical engine and the Mie scattered light has been replaced with an air-ethanol mixture to utilize atomized fuel spray for the visualization purposes. This results have been compared with steady flow concentration measurement. For no swirl port, the axial penetration depends on the fuel injection timing. The fuel tends to remain in the upper region of the cylinder far from the spark plug and the distribution is not affected by the injection timing except 90 ATDC.
The Effect of Injection Pressure Variations on the Smoke and Fuel Consumption in a Small HSDI Diesel Engine with Common Rail Injection System
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 28~34
Great attentions are paid to HSDI diesel engine for passenger cars because of its high thermal efficiency. The most interesting research in HSDI diesel engine developments is focused on applying common rail system as a fuel injection equipment. In this study, a series of tests are carried out to investigate the effect of injection pressure variation on the smoke and fuel concluded in a small HSDI diesel engine with common rail system. As a result of this study it is concluded that there is an optimum rail pressure dependent on combustion system such as nozzle type, combustion chamber geometry
The Experimental Study on the Removal of Diesel Engine Pollutant Emissions Using DC Non-Thermal-Plasma(NTP)
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 35~42
The diesel engine exhaust gas is know as one of the causes to produce photochemical smog, which causes damage on environmental. However, due to the high thermal efficiency and low carbon dioxide emission, the usage of a diesel engine is prevailed. In this study, the DC non-thermal plasma technology used to the particulate matter (PM) aftertreatment. The exhaust gas characteristics and energy density were investigated on the dynamometer test bed and chassis dynamometer with CVS-75 mode in a passenger diesel car. It was reported that the smoke removal efficiency has around the 70% in the dynamometer test with 80W energy consumption and the PM removal efficiency has the 68% in the real car test. The NOx also reduced the 20% according to electrode type respectively. Considering these results, plasma technology is one of the ways to simultaneously removing method the particulate matter (PM) and NOx.
Fast Light-Off of Catalyst using Cranking Exhaust Gas Ignition
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 43~49
In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition(CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst, In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.
Characteristics of Spray Development from Vapor/Liquid Phase Distribution for GDI Spray
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 50~58
The purpose of this research is to obtain the information of the development process of a vaporizing GDI spray using exciplex fluorecence method. Fluorobenzene/DEMA system was used as the exciplex-forming dopants. The 2-D spray images of liquid and vapor phases were acquired, and the behavior of both phases was analyzed by the image processing. The experiment was performed at the three different ambient perssures and the ambient temperature of 273K and 473K. As the result of this work, it was found that the development characteristics of GDI spray have stronger effect on the ambient pressure than on the ambient temperature. With an increase of ambient pressure, the distribution of vapor phase was decreased and the concentration of that was denser. Two regions, namely cone and mixing regions could be identified from those resulrs.
A Study on Estimate of Flow Coefficient with Variation of Hole Number in Multi-hole Diesel Nozzle
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 59~66
This experimental study is to investigate the flow characteristics of the multi-hole nozzle used in the fuel injection system of a heavy-duty diesel engine. A multi-hole diesel nozzle with a 2-spring nozzle holder was used in this study and without changing the total orifice exit area, its hole number varied from 3(
=0.42mm) to 8(
=0.25mm). The injection pressure and needle lift were measured and Bosch type injection rates measurement system was used. The discharge flowrates of each orifice in the multi-hole nozzle changed by the flow conditions inside the nozzle sac hole. In case that pump speed and injection quantity were low, the orifice located in the vertex of nozzle tip had a great deal of injection quantity compared with that of others. As the increment of multi-hole number, the injection duration and the mean injection pressure decrease. The mean and peak injection rates, however, increase. Actually, the mean flow coefficient(
) increases, too. The flow coefficient of the multi 8 hole was evaluated as Cd(mean)=0.74 and that is the maximum value among the examined conditions.
Reducing Exhaust Hydrocarbon at Gasoline Engine with Catalytic Converter using Synchronized Secondary Air Injection
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 67~74
A synchronized secondaty air injection method has been developed to hydrocarbon emission by injecting secondary air intermittently into exhaust port. The method has been tested in a single cylinder spark-ignition engine operating at cold-steady / cold-start conditions. Effects of air injection timing, intake pressure and engine air-fuel ratio have been investigated at cold-steady condition. Also, hydrocarbon emission and exhaust gas temperature with catalytic conberter are compared with a continuous SAI method and base condition at cold-start condition. Resules show that hydrocarbon reduction rate and exhaust gas temperature are sensitive to the timing of synchronized SAI. At cold-steady condition, HC emission is minimum at engine air-fuel ratio of 10. At cold-start condition, the accumulated hydrocarbon emission during the first 120 s decreases about 56% and 22% with the synchronized and continuous SAI, respectively, compared to that of base condition.
Combustion Characteristicsof Plasma JetIgnition for Different Swirl Velocity in a Constant Volume Vessel
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 75~83
This paper presents the evaluation of combustion characteristics of sing-hole plasma jet ignitions in comparison with conventional spark ignition for variable of swirl velocity. Plasma jet plugs are three types according to ejecting directions : center of chamber, positive and negative swirl flow direction. Experiments are carried out for equivalent ratio 1.0 of LPG-air mixture in a constant volume cylindrical vessel. Not only the flame propagation is photographed at intervals, but the pressure variation in the combustion chamber is also recorded throughout the entire combustion process. The results show that the plasma jet ignitions and spark ignition enhance the overall combustion rate by increasing the swirl velocity. The dependence of the combustion rate swirl velocity leade to the conclusion that the placma jet plug, which ejects plasma jet to the cwnter of combustion chamber is the most desirable ignitor than other plugs.
An Experimental Study on the Pressure Distribution for the Surface of a Road Vehicle Model Subjected to Various Wind Direction
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 84~91
To investigate the aerodynamic characteristics of the on a road vehicle, experimenrs were performed at an Atmospheric Boundary Layer Wind Tunnel. The scaled model of an automobile with 1 : 3 scaling ratio was used. The Reynolds number based on the free stream velocity and model length was
. The influence of crosswind to the stability of automobile was investigated by the pressure distribution measurements and flow visualization studies. with the variation of the angle of attack, the change in pressure coefficient depends highly on the flow separation regimes. The experimental and numerical results are compared and found to be in good agreements.
A Study on the Thermal Stress Analysis of a Piston in a Turbocharged Diesel Engine
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 92~98
We determined the transfer coefficient through the analysis of three dimensional temperature distribution in comparison with the measured temperature on the piston in the turbocharged diesel engine. And we analyzed the thermal stress and the thermal deformation with that heat transfer coefficient by using finite element method. According to this results, we found that maximum tempetature range of the piston appeared at the upper part of the piston crown and that the heat transfer coefficient of the upper part of the piston is smaller than that of the lower one. It showed that the maximum thermal deformation is shown at the edge of the upper part of piston and that the maximum thermal stress was shown on the lower part of the piston crown. Finally, we defined the method of determination of a piston heat transfer analysis by using measured temperature on the piston and analyzed temperature with finite element method.
Optimum Design of A-Pillar Trim for Occupant Protection
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 99~106
NHTSA has been conducting biomechanical studies to reduce inujuries sustained sustained during automotive collision. Furthermore, NHTSA added the regulation to the FMVSS 201, limiting the equivalent HIC(Head Injury Criterion) value under 1000. In the presont work, a methodology was developed for the optimum design of the A-pillar trim with rib-structures. The design variables for the rib-strucrures were the transverse spacing, the longitudinal spacing, and the thickness. The required sets of the design varibles were decided based on the design of experiments. The head impact simulations were carried out using the LS-DYNA3D, and the HIC(d) values were computed using the resulrs of the head impact simulation. The objective function was constructed using the response surface methed (RSM). When the obtained optimum values were not inside the region of interest, the design proceduers were repeated by changing the region of interest. Finally, an A-pillar trim with rib-structures, which resulred in HIC(d) value under 850 for 15 mph head-trim impact, was developed.
A Study on the Practical Load with T-shape Joint Structure by the FEA
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 107~115
It is required more precise analysis for practical load because of complexities and varieties of vehicle structure. To establish the numerical model, many researchers have been developed designing tools for linking F.E. Analysis results and experimental results. There studies have generally focused on each experimental method or analytical method separately. There are few studies based on both methods. This paper conceives new procedure for the determination of the load direction and magnitude applied on mechanical structures. New procedure is the combination of the analytical and empirical method with analyzed strain by F.E. Analysis under unit load and with measured principal stress by strain gages under driving load, respectively. In this paper, we theorize the procedure of practical load determination and make the validity and the practicality of the procedure with the application to T-shape jointed structure. F.E. Analysis is conducted to get the principal stress on arbitrary points in the F.E. model of T-shape joint under unit load. Then experiment is carried out to get the principal stress on the same points of F.E. model. To demonstrate the actual driving condition, the load conditions are bending and torsion. From these two data sets, the magnitude, the direction and the position of load can be obtained. Theory and practice do not always coincide; since there are some errors such as ill-poseness, measuring error and modeling error in experimental data, we examine the proper method of error minimization.
Determination of Crash Pulse to Minimize Injuries of Occupants and Optimization of Crash Components Using Response Surface Method
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 116~129
Traditional occupant analysis has been performed with a pre-determined crash puse which is produced from a test and the involved components are designed based on the analysis resuls. The method has limitations in that the design does not have much freedom. Howrver, if a good crash pulse is proposed, the body structure can be modified to generate the crash pulse. Therefore, it is assumed that the crash pulse can be changed to imptove the occupant crash performance. A preferable crash pulse is determined to minimize the occupant injuty. A constraint is established to keep the phenomena of physics valid. The response surface method(RSM) is adopted for the optimization process. An RSM in a commercial code is utilzed by interfacing with an in-house occupant analysis program called SAFE(Safety Analysis For occupant crash Enviroment). Design of involved components called is carried out through optimization with the RSM. The advantages of the RSM are investigated as opposed to other methods, and the tesults are compared. Also, the design under the new crach pulse is compared with that trom the pre-detetmined pulse.
Application of a Brake Pressure Restriction Valve to a Motorcylce ABS
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 130~136
This paper presents an of a brake pressure restriction valve to a motorcycle anti-lock brake system(ABS). In the conventional anti-lock brake system of automobiles, slip ratio as a control variable is actively controlled, which requires wheel speed sensors, ECU, and a pressure modulator. In the ABS valve that has been developed for use in motorcycles, however, the brake pressure that is close to the wheel locking pressure is preset by simple exercises and then the valve just allows to pass the wheel locking pressure and cutoff the remaining pressure. Simulation studies with a single wheel braking dynamics and lumped chassis model show that the pressure restriction valve has basic ABS functions as well as some robustness properties for the uncertain load and road conditions as well as various initial braking speeds. Field tests also show that the pressure restriction valve avoids the wheel locking effectively.
Throttle/Brake Combined Control for Vehicle-to-vehicle Distance and Speed Control
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 137~142
A throttle/brake control law for the intelligent cruise control(ICC) systems has been proposed in this paper. The ICC system consists of a vehicle detection sensor, the control algorithm and a throttle/brake actuators. The control performance has been investigated through vehicle tests. The test vehicle is equipped with a MMW radar sensor, a solenoid-valve-controlled Electronic-Vacuum-Booster(EVB) and a step-motor controlled throttle actuator. The results indicate the proposed throttle/brake control laws can provide satisfactory vehicle-to-vehicle distance and velocity control performance.
A Study on Operational Software Development and Calibration of Multi-Axis Vibration Testing Device
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 143~151
In the recent day, fatigue life prediction techniques play a major role in the design of components in the ground vehicle industry. Full scale durability testing in the laboratory is an essential of any fatigue life evaluation of components or structure of the automotive vehicle. Component testing is particularly important in todey's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, Multi-axis durability testing device is used to carry out the fatigue test. In this paper, The operation software for simultaneously driving Multi-axis vibration testing device is developed and the input and output data are displayed in windows of PC controller with real time. Moteover the characteristics of the displacement and the load of Multi-axis actuators are calibrated separately.
A Simulation Program for the Braking Characteristics of Tractor-Semitrailer Vehicle
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 152~167
Recently safety systems for the commercial vehicle have been rapidly developed. However, we still have many problems in the vehicle stability and the braking performance. Especially, a commercial vehicle may meet a dangerous braking condition when the vehicle is lightly loaded or empty and when the road is wet or slippery. Under these conditions, the truck can spin out or the tractor can jackknife or the trailer can swing out. To design the air brake system for the commercial vehicle, since the air brake system has many design variables, there must have been intensive researches on a method how to prevent dynamic instability and how to maximize the vehicle deceleration. In this study, mathematical models about the tractor-semitrailer and the air brake system including an ABS controller have been constructed for computer simulation. Also, simple examples are applied to show the usefulness of the program. Designers can use this simulation program for understanding the braking characteristics such as trajectory, braking distance, longitudinal deceleration, lateral deceleration, and yaw rate on various road conditions.
A Study on Noise Transfer Path Analysi for Sound Improvement of Vehicle Using the Vibrational Power Flow
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 168~175
Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do net quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.
Estimator Design for Road Friction Coefficient and Body Sideslip Angle for Use in Vehicle Dynamics Control Systems
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 176~184
The VDC(Vehicle Dynamics Control) is a control system whose target is to improve vehicle stability under critical motion. The system has a good potential of becoming a standard active safety unit in passenger vehicles since it can be implemented on top of the ABS/TCS system with little extra cost. This, however, is possible only when the signals that the VDC system demands can be obtained with sufficient accuracy. In this research, estimators for the road friction coefficient and body sideslip angle have been designed. The two variables have great influence upon performance of the VDC system but not directly measurable. For the estimator design, the Newton method and the nonlinear observer theory have been exploited. The performance of the estimator have been verified via simulations on critical driving conditions.
Development of Powertrain Model for Vehicle Dynamic Analysis Program, AutoDyn7
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 185~191
In many papers, the powertrain system generally has been madeled as one-dimensional torque model. One-dimensional powertrain model may calculate the torque correctly but it does not consider the non-rotational degrees-of-freedom of the powertrain components and the interaction of these degrees-of-freedom with the vehicle body frame and suspension. To consider the non-rotational degrees of freedom, the differential is modeled as a three-dimensional rigid body in this paper. A constant velocity joint is newly formulated and a relative constraint is also formulated to model the motion transfer due to gear ratio of the differential. Implementing the proposed powertrain system in the multibody model, more detail dynamic responses can be obtained. Obtained outputs such as reaction torques on the constant velocity joint and reaction forces on the rack can be useful data in the design of a powertrain.
Damping performance Analysis for an Electronically Contralled Shock Absorber
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 192~201
Analyzing internal structure, flow rate and dynamic behavior characteristics of electronically controlled shock absorber, damping performance limit is identified to comprise the two reciprocal characteristics of ride comfort and handling safety. Regardless of its lower performance than the active suspension control system, the semi-active suspension control system has been taking interest because of its absolutely higher performance than passive suspension system. Since the pervious studies have been concentrated mostly on analytic aspect and survey on the internal structure of the shock absorber remain insufficient, the main discourse of this paper is focused on analyzing the nonlinear shock absorber which varies the damping force of semi-active suspension system and the dynamic characteristics of the solenoid valve, a sort of pressure valve, and proposing the design factors of importance.
A Study on Converter OBD
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 202~209
As a part of stringent emission regulations, OBD on a converter is requested by EU and CARB. It demands that MIL is light-on to inform the failure to the driver when the converter is failed in its function. Usually dual oxygen sensor method is used for converter OBD. For this, detail methods, like amplitude ratio, time delay and frequency ratio methods are adapted for vehicle application. Actually, the cars produced later than MY94 for US market are using one of these methods. In this study, OSCs of converters are investigated with an absolute measuring method. The converters are aged with a furnace aging, an engine bench aging and vehicle aging method to represent various aging condition in field applications. An OBD index that is used for TLEVs regulation is also investigated to find a relation between two parameters. The relations of these parameters with THC emission on vehicle are evaluated.
Development of Wiper Antenna for Automobile using Single Sleeve Monopole
Transactions of the Korean Society of Automotive Engineers, volume 9, issue 2, 2001, Pages 210~215
The pole antenna of vehicles for AM/FM radio broadcasting receptions has many probems, such as damageable mechanical system and noise etc. It is considered that noise is composed of the structural vibration noise and the air flow induced aerodynamic noise. Also we find out that the setting process of a printed on-glass automobile antenna has many difficulties. Recently, the above mentioned problems can be reduced by employing enhanced wiper antenna which utilizes the windshied wiper arm. The new system is a passive antenna. In this study, experiments for the characteristics of a wiper antenna by measuring the SWR, radiation pattern and received powe have been carried out. The experimental results show that the efficiency of the wiper antenna has better performance than any other antenna.