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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 14, Issue 6 - Nov 2006
Volume 14, Issue 5 - Sep 2006
Volume 14, Issue 4 - Jul 2006
Volume 14, Issue 3 - May 2006
Volume 14, Issue 2 - Mar 2006
Volume 14, Issue 1 - Jan 2006
Selecting the target year
A Fundamental Study on the Investigation of Bubbling Phenomenon in the Injector for the Development the LPDi Engine
Noh, Ki-Chol ; Lee, Jong-Tai ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 1~8
One of the most important subjects to develop a LPDi engine is to suppress the bubble generated inside the liquid LPG direct injector. For the purpose of this, the analogy visualization injector to visualize the generation and behaviors of bubble is manufactured, and the bubbling phenomenon and behaviors of bubble are visualized and investigated according to the change of the temperature around an injector wall, fuel pressure and a needle configuration. As results, it was found that the bubble inside the injector is generated around an injector hole and after rising by buoyancy it disappears around the top of a nozzle. The number of bubbles generated is little changed regardless of the lapse of time but it remarkably increases as the temperature around the injector increases. Also, it was known that as the sac volume in LPDi injector decreases the generation of bubble is more active and the rising velocity of bubble generated is increased.
Knocking and Combustion Characteristics at Rich Limit of Gasoline HCCI Engine
Yeom, Ki-Tae ; Jang, Jin-Young ; Bae, Choong-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 9~16
Variable valve timing is one of the attractive ways to control homogeneous charge compression ignition (HCCI) engine. Hot internal residual gas which can be controlled by variable valve timing(VVT) device, makes fuel evaporated easily, and ignition timing advanced. Regular gasoline was used as main fuel and di-methyl ether(DME) was used as ignition promoter in this research. HCCI engine operating range is limited by high combustion peak pressure and engine noise. High combustion pressure can damage the engine during operation. To avoid engine damage, the rich limits have to define using various methods. Peak combustion pressure, rate of cylinder pressure rise was considered to determine rich limit of engine operating range. Knock probability was correlated with the rate of cylinder pressure rise as well as the peak combustion pressure.
Prediction of Durability, Static and Dynamic Properties on Rubber
Kim, Choon-Hyu ; Kim, Kee-Joo ; Jeong, Hyo-Tae ; Kim, Cheol-Woong ; Sohn, Il-Seon ; Kim, Joong-Bae ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 17~23
Rubber materials have the nonlinear, large deformation and viscoelastic behavior. W.D. Kim et al. studied these characteristics through the static, fatigue, dynamic, aging and viscoelastic test. This paper discussed that the properties of engine mounting rubber, such as static stiffness, fatigue life and damping factor, are predicted based on CAE by using material properties acquired by the report of Kim et al. In result, the static stiffness of engine mounting rubber is predicted approximately in comparison with test value. Also, it was confirmed that the relationship of fatigue life and Green-Lagrange strain in specimen was the valid tool to predict the fatigue life of engine mounting rubber. From the results of transient viscoelastic analysis the damping factor changed rapidly at the range less than 8hz.
A Study of Increasing Regeneration Energy and Braking Using Super Capacitor(EDLC)
Kwon, Oh-Jung ; Park, Chang-Kwon ; Oh, Byeong-Soo ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 24~33
This experiment explains about electrical braking equipment which will be used for 1.2kW PEMFC HEV. The equipment is made of BLDC motor and super capacitor(EDLC). The circuit is designed for regeneration braking that can save the energy from low voltage of generation with BLDC motor. Increasing a regeneration energy from braking system is effected with regeneration current and SoC of super capacitor(EDLC). Electrical braking in electrical vehicle is suitable for regeneration braking with dynamic braking together.
Development of Predictive Smoothing Voter using Exponential Smoothing Method
Kim, Man-Ho ; Lim, Chang-Hwy ; Lee, Suk ; Lee, Kyung-Chang ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 34~42
As many systems depend on electronics, concern for fault tolerance is growing rapidly. For example, a car with its steering controlled by electronics and no mechanical linkage from steering wheel to front tires(steer-by-wire) should be fault tolerant because a failure can come without any warning and its effect is devastating. In order to make system fault tolerant, there has been a body of research mainly from aerospace field. This paper presents the structure of predictive smoothing voter that can filter out most erroneous values and noise. In addition, several numerical simulation results are given where the predictive smoothing voter outperforms well-known average and median voters.
Correlations among Different Tumble Measuring Methods and Significance of Tumble Ratios from Steady Flow Rig on SI Engine Combustion
Lee, Si-Hun ; Kim, Myoung-Jin ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 43~49
Optimizing in-cylinder flow such as tumble or swirl is one of the key factors to develop better internal combustion engines. Especially, the tumble, which is more dominant flow in current high performance gasoline engines, has significant effects on the fuel consumptions and exhaust emissions under part load conditions. The first step for the tumble optimization is to find an accurate but cost-effective way to measure the tumble ratio. From this point of view, tumble ratios from three different measuring methods were compared and correlated in this research. Steady flow rig, water rig, and PIV were utilized for that purpose. Engine dynamometer test was also performed to find out the effect of the tumble. The results show that the tumble ratios from those methods are well correlated and that the steady flow rig is the effective method to measure the tumble despite its limitations.
Numerical Analysis of Flow Characteristic of Residual Gas due to Changes in Valve Timings during an Idle Operation in an SI Engine
Lee, Joon-Ho ; Kim, Duk-Sang ; Baik, Doo-Sung ; Cho, Yong-Seok ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 50~56
Residual gas fraction in a combustion process is very crucial to improve combustion and cyclic variations. Especially, the residual gas fraction is strongly affected by backflow of the residual gas during the valve overlap period in an idle operation. Therefore, it is one of the most interesting that valve timings can affect flow characteristics of gas exchange process, especially during idle operation. This analysis investigates residual gas fraction with respect to valve timing changes which is critical for combustion efficiency and engine performance. Flow characteristics of residual gas by changing intake and exhaust valve timing are calculated by CFD methodology during an idle operation in an SI engine. It is analyzed that retarded EVO and advanced IVO results in the increase of valve overlap period and consequently, residual gas fraction. Futhermore, changes in IVO have stronger effects on variation of residual gas fraction.
Approximate Function Method for Real Time Multibody Vehicle Dynamics Model
Kim, Sung-Soo ; Lee, Chang-Ho ; Jeong, Wan-Hee ; Lee, Sun-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 57~65
An approximate function approach has been developed using the subsystem synthesis method for real-time multibody vehicle dynamics models. In this approach, instead of solving loop closure constraint equations of the suspension linkage, approximate functions are used. The approximate function represents the functional relationship between dependent coordinates and independent coordinates of the suspension subsystem. This kinematic relationship is also included in the suspension subsystem equations of motion. Different order of polynomial functions are tried to find out the best candidate functions. The proposed method is also compared with the conventional subsystem synthesis method to verify its efficiency and accuracy.
Analytical Investigation on the Track Separation Mechanism for Tracked Excavator
Lee, Yun-Sig ; Ok, Jin-Kyu ; Kim, Hyo-Joon ; Yoo, Wan-Suk ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 66~72
In this paper, an analytical investigation on the track separation mechanism for tracked excavator was studied. Relative motions of track links, sprocket, idler and support rollers are very important in the driving of an excavator The interference and friction between each components lead to noise and vibration. And also this has a great influence on the life for tracked excavator. RecurDyn program was used for the three dimensional modeling of the track assembly. Investigating the interference between sprocket and track links, the mechanism of the track separation was analyzed.
Development of Conversion Technology of a Decrepit Diesel Vehicle to the Dedicated Natural Gas Vehicle
Ryu, Kyung-Hyun ; Kim, Bong-Kyu ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 73~81
A commercial diesel engine was converted into a dedicated natural gas engine to reduce the exhaust emissions in a retrofit of a diesel-fueled vehicle. The cylinder head and piston were remodeled into engine parts suited for a spark ignition engine using natural gas. The remodeling of the combustion chamber changed the compression ratio from 21.5 to 10.5. A multi-point port injection(MPI) system for a dedicated natural gas engine was also adopted to increase the engine power and torque through improved volumetric efficiency, to allow a rapid engine response to changes in throttle position, and to control the precise equivalence ratio during cold-start and engine warm-up. The performance and exhaust emissions of the retrofitted natural gas engine after remodeling a diesel engine are investigated. The emissions of the retrofitted natural gas engine were low enough to satisfy the limits for a transitional low emission vehicle(TLEV) in Korea. We concluded that a diesel engine can be effectively converted into a dedicated natural gas engine without any deterioration in engine performance or exhaust emissions.
Behavioral Adaptation to an Adaptive Cruise Control System
Lee, Woon-Sung ; Kim, Young-Suk ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 82~88
The study investigated how an adaptive cruise control system induced behavioral adaptation in drivers using a full-scale driving simulator. Forty drivers with different driving styles participated in the study to compare headway-time, vehicle lateral position variation, and head and eye movement when driving with and without the adaptive cruise control system. Results showed that system induced positive behavioral adaptation by drawing consistency in driving speed and headway-time regardless of the driving styles. However, the results also showed that the drivers' reliance on the system induced negative adaptation including reduced lane keeping ability and reduced attention during driving. As a strategy to prevent negative adaptation, the study proposed information service to drivers with the adaptive cruise control system status and driving environment, and investigated effectiveness of the service. Twelve drivers participated in the experiment to compare headway-time, vehicle lateral position variation and subjective ratings when driving with and without the information service. Results showed that the information service assisted the drivers to maintain safer and more comfortable headway-time without impairing drivers' steering ability.
The Real Time Measurement of Dynamic Radius and Slip Ratio at the Vehicle
Lee, Dong-Kyu ; Park, Jin-Il ; Lee, Jong-Hwa ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 89~94
The tire delivering power generated from engine to the ground pulls a vehicle to move. Radius of tires is changeable due to elasticity that depends on the speed of vehicle and traction force. The main objectives on this study are real time measurement of dynamic radius and slip ratio according to the speed and traction force. The dynamic radius is proportional to speed and traction force. According to measurement, the dynamic radius is increased about 3mm under 100km/h compared to stop. It is also increased about 1.5mm when a traction force is supplied as much as 4kN compared to no load state at low speed. There is no strong relationship between slip ratio and vehicle speed. The slip ratio is measured up to 4% under WOT at first stage gear. Through this research, the method of measuring dynamic radius and slip ratio is set up and is expected to be applied to the measurement of traction force in chassis dynamometer or accelerating and climbing ability.
A Study on the Brake Frictional Heat between Wheel Tread and Brake Shoe of E.M.U.'s
Kim, Seong-Keol ; Yoon, Cheon-Joo ; Goo, Byeong-Choon ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 95~103
Wheel treads of E.M.U. are usually under a heavy thermal load by brake frictional heat between wheel and brake shoe and damaged by repeated thermal and mechanical loads. To examine the cause of wheel tread damage of E.M.U.'s in service running, a systematic approach has been used. This study is composed of three parts. Frictional heat analysis was conducted in the first part by finite element method. Two kinds of brake shoes in service were considered. In the second part, experimental study was carried out on a brake dynamometer. Temperatures were measured for the two brake shoes. And experimental study in service running E.M.U.'s was performed. Wheel and brake shoe temperatures were measured by using thermocouples and temperature indicating strips. Finally metallurgical characteristics were examined by a SEM/EDS and the cause of the wheel damage was analyzed. It seems that aggregated ferrous component is a main cause of the wheel tread damage.
Measurement of Local Heat Transfer Coefficients and Numerical Analysis in the Flow Passage of Disc Brake with Spirally Grooved Surfaces
Lee, D.H. ; Park, S.B. ; Lim, C.Y. ; Kim, H.S. ; Lee, K.S. ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 104~111
A ventilated disc brake having spirally fluted surface has been proposed to improve the thermal judder by way of heat transfer enhancement. The local heat transfer coefficients were measured in the flow passage of disc brake. These measured local heat transfer data were utilized to do the finite element numerical analysis which predicts the maximum temperatures on the disc brake. The results show that the maximum temperatures on the disc surface with spirally fluted surface are approximately 26.6% lower than those without them.
Light-weight Design with a Simplified Center-pillar Model for Improved Crashworthiness
Bae, Gi-Hyun ; Huh, Hoon ; Song, Jung-Han ; Kim, Se-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 112~119
This paper is concerned with the light-weight design of a center-pillar assembly for the high-speed side impact of vehicle using advanced high strength steels(AHSS). Steel industries continuously promote the ULSAB-AVC project for applying AHSS to structural parts as an alternative way to improve the crashworthiness and the fuel efficiency because it has the superior strength compared to the conventional steel. In order to simulate deformation behavior of the center-pillar assembly, a simplified center-pillar model is developed and parts of that are subdivided employing tailor-welded blanks(TWB) in order to control the deformation shape of the center-pillar assembly. The thickness of each part which constitutes the simplified model is selected as a design parameter. Factorial design is carried out aiming at the application and configuration of AHSS to simplified side-impact analysis because it needs tremendous computing time to consider all combinations of parts. In optimization of the center-pillar, S-shaped deformation is targeted to guarantee the reduction of the injury level of a driver dummy in the crash test. The objective function is constructed so as to minimize the weight and lead to S-shape deformation mode. Optimization also includes the weight reduction comparing with the case using conventional steels. The result shows that the AHSS can be utilized effectively for minimization of the vehicle weight and induction of S-shaped deformation.
Vehicle Dynamic Characteristics according to the Coherence of Road Roughness between Left and Right Wheels
Choi, Gyoo-Jae ; Jang, Bong-Choon ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 120~126
Vehicle dynamic simulation has been carried out using the coherence of road roughness between left and right wheels. The generated twin tracks with the coherence of road roughness between left and right wheels are in good agreements with the measured coherence relation of left and right wheels. And these tracks reflect well on the roughness characteristics of real roads. Using the generated roads and multibody dynamic simulation program, vehicle dynamic simulation is performed. The vertical and roll motion analysis of a vehicle are carried out using the realistic road profiles with the coherence between left and right wheels and the results are in good agreements with the dynamic characteristics of a vehicle.
Rigorous Modeling of Single Channel DPF Filtration and Sensitivity Analysis of Important Model Parameters
Jung, Seung-Chai ; Park, Jong-Sun ; Yoon, Woong-Sup ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 127~136
Prediction of diesel particulate filtration is typically made by virtue of modeling of particulate matter(PM) collection. The model is closed with filtration parameters reflecting all small scale phenomena associated with PM trapping, and these parameters are to be traced back by inversely analyzing large-scale empirical data-the pressure drop histories. Included are soot cake permeability, soot cake density, soot density in the porous filter wall, and percolation constant. In the present study, a series of single channel DPF experiment is conducted, pressure histories are inversely analyzed, and the essential filtration parameters are deducted by DPF filtration model formulated with non-linear description of soot cake regression. Sensitivity analyses of model parameters are also made. Results showed that filtration transients are significantly altered by the extent of percolation constant, and the soot density in the porous filter wall is controlling the filtration qualities in deep-bed filtration regime. In addition, effect of soot particle size on filtration quality is distinct in a period of soot cake regime.
A Study on the Geometry Decision of Catalytic Converter for Motorcycle
Yi, Chung-Seub ; Chung, Han-Shik ; Jeong, Hyo-Min ; Suh, Jeong-Se ; Lee, Cheol-Jae ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 137~142
This research represents the catalytic converter for application in the motorcycle. Present research model type is monolithic catalytic converter and this type have been widely used for satisfaction on and the regulations of pollutant emissions in automobiles. The flow characteristics in a single monolith automotive catalytic converter were investigated by using a computational simulation method without chemical reaction. So we limit the discussion to the effect of flow uniformity in the catalytic converter. Simulation result shows that the flow uniformity of megaphone type catalytic converter is higher than that of a base type. Therefore, the megaphone type is more suitable to motorcycle.
Development of a New Bushing Model for Vehicle Suspension Module Design
Ok, Jin-Kyu ; Park, Dong-Woon ; Yoo, Wan-Suk ; Sohn, Jeong-Hyun ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 143~150
In this paper, a new bushing model for vehicle dynamics analysis using Bouc-Wen hysteretic model is proposed. Bushing components of a vehicle suspension system are tested to capture the nonlinear behavior of rubber bushing elements using the MTS 3-axes rubber test machine. The results of the tests are used to define parameters in Bouc-Wen bushing model, which was employed to represent the hysteretic characteristics of the bushing. Bushing parameters are obtained by using genetic algorithms and sensitivity analysis of parameters are also carried out. ADAMS program was used for the identification process and VisualDOC program was employed to find the optimal parameters. A half-car simulation was carried out to show the usefulness of the developed bushing model.
Prediction of Fuel Cell Performance and Water Content in the Membrane of a Proton Exchange Membrane Fuel Cell
Yang, Jang-Sik ; Choi, Gyung-Min ; Kim, Duck-Jool ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 151~159
A one-dimensional numerical analysis is carried out to investigate the effects of inlet gas humidities, inlet gas pressures, and thicknesses of membrane on the performance of a proton exchange membrane fuel cell. It is found that the relative humidity of inlet gases at anode and cathode sides has a significant effect on the fuel cell performance. Especially, the desirable fuel cell performance occurs at low relative humidity of the cathode side and at high humidity of the anode side. In addition, an increase in the pressure ranging from 1 atm to 4 atm at the cathode side results in a significant improvement in the fuel cell performance due to the convection effect by a pressure gradient toward the anode side, and with decreasing the thickness of membrane, the fuel cell performance is enhanced reasonably.
Multi-function Control of Hydraulic Variable Displacement Pump with EPPR Valve
Jung, Dong-Soo ; Kim, Hyong-Eui ; Kang, E-Sok ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 160~170
If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.
Concentration Interaction of Premixed and Triple-layer Flames in Lean Burn with Methane Fuel
Oh, Tae-Kyun ; Chung, Suk-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 171~178
The performance in the practical combustion system including reciprocating engines and gas turbine combustors is being much governed by turbulent reacting flow that is often analyzed by both a laminar flamelets concept and flame interaction. The characteristics of laminar flame interaction have been investigated numerically to provide basic understanding of wrinkled turbulent flames under concentration interaction resulting from inhomogeneity in fuel-air mixing, especially focused on the transition of flame characteristics such as diffusion flame, partially premixed diffusion flame, and triple-layer flame by the variation in the degree of premixedness. The extinction stretch rates to the premixedness have also been obtained in this paper. The boundary defining the regime of the existence of triple-layer flames as functions of both stretch rate and premixedness has been determined which agrees well with previously reported experiment measuring OH radical concentration peaks based on PLIF.
Consideration for the Vehicle Head Restraint Geometry Test Method
Shim, So-Jung ; Hwang, Duk-Soo ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 179~183
Whiplash injuries of the neck are one of the most common injuries reported from automotive rear impacts. Whiplash injuries can be reduced by changing geometry of head restraint. Therefore, geometries of head restraint were evaluated according to the test procedures of the Korea New Car Assessment Program(KNCAP) to improve safety of head restraint. In this study, nine vehicle's head restraints were tested. As the test results, one head restraints is rated at "Marginal", three head restraints are rated at "Acceptable" level, and the last five head restraints are rated at "Good" level.
A Study on the Tumble Flow Test Rig Used to Developing Engine Induction System
Yun, Jeong-Eui ; Kim, Myung-Hwan ; Nam, Hyeon-Sik ; Min, Sun-Ki ; Sim, Dae-Gon ; Park, Pyeong-Wan ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 184~189
Tumble flow test rig has been used as the useful tool in the developing intake system because major flow pattern induced by intake port of DOHC engine is tumble. Angular momentum of in-cylinder tumble flow can not be directly measured by impulse torque meter in the test rig like that of in-cylinder swirl flow due to rotational axis of the flow. Therefore the adaptor to transform tumble to swirl flow must be adapted in the test rig. In this study, using the commercial CFD code STAR-CD, we studied the effects on measured results due to the variation of the major design variables in the adaptor, tube length(L), tube diameter(D) and cylinder height(H). The effect of the attached angle(
) of the test head to the adaptor also was simulated.
A Study on Vehicle Crash Characteristics with RCAR Crash Test in Compliance with the New Test Condition
Lim, Jong-Hun ; Park, In-Song ; Heo, Seung-Jin ;
Transactions of the Korean Society of Automotive Engineers, volume 14, issue 6, 2006, Pages 190~194
This research investigates vehicle structure acceleration and vehicle deformation with RCAR crash test. To investigate vehicle damage characteristics in an individual case, it is possible to RCAR low speed crash test. In this study, two tests were conducted to evaluate difference between RCAR new condition and RCAR old condition. A two large vehicles were subjected to a frontal crash test at a speed of 15km/h with an offset of 40%
angle barrier and flat barrier. The results of the 15km/h with an offset of 40%
angle barrier revealed high acceleration value on the vehicle structure and high repair cost compared to the RCAR 15km/h with an offset of 40% flat barrier. So in order to improve damage characteristics in low speed crash of vehicle structure and body component of the monocoque type passenger vehicles, the end of front side member and front back beam should be designed with optimum level and to supply the end of front side member as a partial condition approx 300mm.