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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Automotive Engineers
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Journal DOI :
The Korean Society of Automotive Engineers
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Volume & Issues
Volume 13, Issue 6 - Nov 2005
Volume 13, Issue 5 - Sep 2005
Volume 13, Issue 4 - Jul 2005
Volume 13, Issue 3 - May 2005
Volume 13, Issue 2 - Mar 2005
Volume 13, Issue 1 - Jan 2005
Selecting the target year
Vibration Analysis of Non-homogeneous Damped Beam Using the Differential Transformation Method
Shin, Young-Jae ; Jaun, Su-Ju ; Yun, Jong-Hak ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 1~6
In this paper, the natural frequencies of non-homogeneous damped beam are determined by using the differential transformation. The beam considered has different stiffness, damping and mass properties in each of two parts. The various boundary conditions are assumed at each end. The results obtained by the present method agree very well with those reported in the previous works. The present analysis shows the usefulness and validity of differential transformation in solving a non-homogeneous damped beam problem.
A Study on Development of the Reliability Evaluation System for VVVF Urban Transit
Bae Chul-Ho ; Kim Sung-Bin ; Lee Ho-Yong ; Chang Suk-Hwa ; Suh Myung-Won ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 7~18
Over the past twenty years, the maintenance system has been developed and its importance has been increased. For the effective maintenance of the urban transit, we have developed the maintenance system based on the concept of RCM(Reliability Centered Maintenance). RCM analysis is a systematic approach to developing a cost-effective maintenance strategy based on the various components's reliability of the system in question. It is performed according to process that includes the following steps; definition of function and functional failures of the systems, construction of RB D(Reliability Block Diagram), performance of FMEA(Failure Modes & Effects Analysis) and calculation of the reliability index. The final process of RCM is to determine appropriate failure maintenance strategies. This paper aims to define the procedure of maintenace based on the concept of RCM for urban transit. The key for a successful maintenance system is an automated scheduling to the maximum extent possible and timely executions. The developed system issues maintenance plan and repair request based on analyzed data and maintenance experience.
A Study on Effect of Cylinder Back Pressure on Feed Rate and Delivery Characteristics of Motor-driven Lubricator in a Large Two-stroke Diesel Engine
Bae Myung-whan ; Jung Hwa ; Ok Hyun-jin ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 19~28
It is of great economic importance to minimize the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine. The motor-driven cylinder lubricator was first developed fur a large two-stroke marine diesel engine made in
Switzerland Ltd. by the joint research of industry-university. In this study, the effects of revolution speed, plunger stroke and cylinder back pressure on maximum discharge and delivery pressures, delivery delay duration, and oil feed rate are experimentally investigated by the home-manufactured cylinder lubricator. The maximum discharge pressure with a spot of 0.03 m and the maximum loss pressure at spots of 5, 6.78 and i 0 m away from the end of lubricator slot are increased as plunger stroke, revolution speed and back pressure are elevated, and the delivery delay duration is shortened as plunger stroke, revolution speed and oil pipe length are increased. Also, oil feed rate is increased as plunger stroke and revolution speed are raised, but lowered as the back pressure is increased.
Stildy on the Methodology to Prevent Neck Injury at tow Speed Rear-End Impact
Park Insong ; Chun Yongbum ; Kim Guanhee ; Lim Jonghun ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 29~34
141,841 car-to-car collision had occurred in 2003, and among the accidents 51,796 were rear-end impact. According to insurance company for loss or damage, more than
of rear-end impact victims suffer neck injury. This means at least 31,000 neck injury victims have happened in 2003. More than
of the neck injury victims have low severity injury than A.I.S 2. Head restraint, which is designed to limit rearward head movement and equipped on seat, can considerably protect neck from rear-end impact. In this paper we evaluated head restraint geometry and drivers' sitting position according to RCAR standard and carried out low speed volunteer crash test. The crash speed is 4km/h and N.I.C value is used to determine injury probability. Through these research results we can introduce the method to prevent neck injury at rear-end impact.
Effect of Cooled-EGR on the Characteristics of Performance and Exhaust in a HCCI Diesel Engine
Lee, Chang-Sik ; Yoon, Young-Hoon ; Kim, Myung-Yoon ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 35~41
The effects of cooled-ECR on the characteristics of combustion and exhaust emissions were investigated in a single cylinder HCCI diesel engine The premixed charge (gasoline or diesel) was obtained with premixing chamber and high-pressure (5.5MPa) injection system. Exhaust pressure control and cooled ECR system were used in order to reduce pressure fluctuation and to mix the exhaust gas well with the fresh intake air. The experimental results show that NOx emissions from conventional diesel engine are steeply decreased by HCCI diesel combustion with cooled-EGR in both case of gasoline and diesel premixing. But soot emissions are rapidly increased with the increase of ECR rate. The recycled exhaust gas increased the ignition delay of mixture and decreased maximum combustion pressure. HC and CO emissions of HCCI combustion are increased with ECR rate.
Evaluation of Welding Characteristics on 3-lap Spot Joint of Zinc Coned Seel Sheet md High Seength Steel Sheet
Kwon Il-Hyun ; Kim Hoi-Hyun ; Baek Seung-Se ; Yang Seong-Mo ; Yu Hyo-Sun ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 42~49
In general, multi-lap spot weld joints are frequently present in automobile. Most research, however, has been focused on the single-lap spot weld joints until now. In this paper, tensile-shear strength tests are performed to examine the weldability of 3-lap spot joint welded by using the high strength steel sheet and the zinc coated steel sheet. The indentation depth and nugget diameter are used to propose the optimum welding conditions. The weldability is affected by the welding current and welding time for 3-lap spot joint. Meanwhile the expulsions is round to decrease with the increase of electrode force. The optimum welding conditions are presented for 3-lap spot joints of high strength steel sheet and zinc coated steel sheet.
A Study on the Axial Crushing Behavior of Aluminum Cm Circular Members for light-weight
Lee, Kil-Sung ; Cha, Cheon-Seok ; Yang, In-Young ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 50~56
Aluminum member absorbs energy by stable plastic deformation under axial loading. While CFRP(Carbon Fiber Reinforced Plastics) member absorbs energy by unstable brittle failure but its specific strength and stiffness is higher than those of aluminum member. In this study, for complement of detects and synergy effect by combination with the advantages of each member, the axial collapse tests were performed for aluminum CFRP members which are composed of aluminum members wrapped with CFRP outside aluminum circular members. Based on the respective collapse characteristics of aluminum and CFRP members, crushing behavior and energy absorption characteristics were analyzed for aluminum CRRP members which have different CFRP fiber orientation angle and thickness Test results showed that aluminum CFRP members supplemented the unstable brittle failure of CFRP members due to ductile nature of inner aluminum members. It turned out that the CFRP fiber orientation angle and thickness influence energy absorption capability together with the collapse mode of the members.
A Study on the Urea-SCR System for NOx Reduction of a light-Duty Diesel Engine
Nam Jeong-Gil ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 57~63
The effects of an urea injection at the exhaust pipe for a 4-cylinder DI(Direct Injection) diesel engine were investigated with the parameters such as urea-SCR(Selective Catalytic Reduction) and EGR system. The urea quantity was controlled by NOx quantity and MAF(Manifold Air Flow). The urea injection quantity can be controlled with the urea syringe pump, precisely. The effects of NOx reduction for the urea-SCR system were investigated with and without ECR engine, respectively. It was concluded that the SUF(Stoichiometric Urea Flow) is calculated and the NOx results are visualized with engine speed and load. Furthermore, the NOx map is made from this experimental results. It was suggested, therefore, that NOx reduction effects of the urea-SCR system without the EGR engine were better than that with the EGR engine except of low load and low speed.
Unsteady Intermittent Spray Characteristics of PEI Gasoline Injector
Kim Beomjun ; Lee Jaiho ; Cho Daejin ; Yoon Suckju ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 64~74
The effect of fuel injection spray on engine performance has been known as one of the major concerns for improving fuel economy and reducing emissions. In general, reducing the spray droplet size could prevent HC emission in gasoline engine. As far as PFI gasoline engine is concerned, the mixture of air and fuel may not be uniform under a certain condition, because breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve. This study, by constituting PFI gasoline spray system, was performed to study the transient spray characteristics and dynamic behavior of droplets from two-holes two-sprays type injector used in DOHC gasoline engine. Mean droplet size and optical concentration in accordance with various conditions were measured by LDPA and CCD camera. Through this study, the variation of drop size and optical concentration could be used for understanding the behavior of unsteady spray was declared and the existing the small droplets between each pulse spray could be estimated caused to the development of wall film was conformed.
Homogeneous Charge Compression Ignition Combustion and Exhaust Characteristics of a Common-rail Diesel Engine
Yoon, Seung-Hyun ; Lee, Doo-Jin ; Kim, Myung-Yoon ; Lee, Je-Hung ; Lee, Chang-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 75~81
An experimental study on homogeneous charge compression ignition combustion with direct fuel injection was conducted using a single cylinder common-rail diesel engine. To improve the homogeneity of fuel-air mixture, the premixed fuel (gasoline) was injected into premixing chamber and the diesel fuel was injected into the combustion chamber as an ignition source for the gasoline premixture. The experimental results show that soot emissions were dramatically reduced with the increase of fuel premixing ratio, however incomplete products such as HC and CO increased with the increase of the premixed ratio. Earlier injection of Dl diesel fuel increased the IMEP with the decrease of HC and CO concentrations.
Effect of Piston Cavity Geometry on Formation and Behavior of Fuel Mxture in a DI Gasoline Engine
Kim Dongwook ; Kang Jeongjung ; Choi Gyungmin ; Kim Duckjool ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 82~89
This study was performed to investigate the behavior and spatial distribution of fuel mixtures with different wall angle and diameter of piston cavity in a DI gasoline engine. The spatial distribution of fuel mixtures after impingement of the spray against a piston cavity is one of the most important. factors for the stratification of fuel mixture. Thus, it is informative to understand in detail the behavior and spatial distribution of fuel mixtures after impingement in the cavity. Two dimensional spray fluorescence images of liquid and vapor phase were acquired to analyze the behavior and distribution of fuel mixtures inside cylinder by exciplex fluorescence method. The exciplex system of fluorobenzene/DEMA in non-fluorescing base fuel of hexane was employed. Cavity wall angle was defined as an exterior angle of piston cavity. Wall angles of the piston cavity were set to 30, 60 and 90 degrees, respectively. The spray impinges on the cavity and diffuses along the cavity wall by its momentum. In the case of 30 degrees, the rolling-up moved from the impinging location to the round and fuel-rich mixture distributed at periphery of cylinder. In the case of 60 and 90 degrees, the rolling-up recircurated in the cavity and fuel mixtures concentrated at center region. High concentrated fuel vapor phase was observed in the cavity with 90 degrees. From. present study, it was found that the desirable cavity wall angle with cavity diameter for stratification in a Dl gasoline engine was demonstrated.
Fatigue Quality Index of Elliptical Holed Plate
Song Joonhyuk ; Shimamoto A. ; Nah Seokchan ; Yu Hyosun ; Kang Heeyong ; Yang Sungmo ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 90~95
Most of mechanical structures are composed of many substructures connected to one another by various types of mechanical joints with various shapes of cutouts. It is important to study these connected structures under dynamic forces for evaluation of stress concentration. In this paper, a FQI(fatigue quality index) analysis using the concept of SF(severity factor) is performed to various shape of elliptical hole. The SF is affected by the location of cutout in plate and radius ratio, static SF is analyzed with finite element analysis and the equation of FQI for predicting a dynamic SF is formed.
Quantification of Thermal Shock in a Piezoelectric Pressure Transducer
Lee, Seok-Hwan ; Choi, Wook ; Bae, Choong-Sik ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 96~103
One of the major problems limiting the accuracy of piezoelectric transducers fur cylinder pressure measurements in an internal combustion (IC) engine is the thermal shock. Thermal shock is generated from the temperature variation during the cycle. This temperature variation results in contraction and expansion of the diaphragm and consequently changes the force acting on the quartz in the pressure transducer An empirical equation for compensation of the thermal shock error was derived from consideration of the diaphragm thermal deformation and actual pressure data. The result indicate that the thermal shock equation provides reliable correction based on known surface temperature swing.
Analysis of Residual Stress Singularities on Interfaces of Friction Welded SUH35/SUH3
Chung, Nam-Yong ; Park, Chul-Hee ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 104~111
With increasing use of SUH35/SUH3 dissimilar materials for automotive engine valves, it is required that stress singularities under residual stress on an interface for friction welded dissimilar materials analyzed to establish strength evaluation. The stress singularity
and stress singularities
were calculated from using the results of stress analysis to consider residual stress and loads. The stress singularities on variations for shapes and thickness of welded flashes were analyzed and discussed. This paper suggested that the strength evaluation by using the stress singularity factors as fracture parameters, considering the stress singularity on an interface edge of friction welded dissimilar materials will be useful.
Spray Behavior and Atomization Characteristics of Dual Stream Gasoline Injectors
Song, Bhum-Keun ; Kim, Won-Tae ; Kang, Shin-Jae ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 112~120
The injector, which is used in a 4-valve gasoline engine, is required to be maintained the dual stream because of the design of dual intake port. In addition, the spray characteristics of fuel injector have strong influence on engine performance, exhaust emission, fuel consumption, and especially the cold start condition for the port injection. So, commercial gasoline injectors off different type were inspected. Those are 2 hole,4 hole, air shroud 4 hole, and air shroud 4 hole injector with separator. The spray behavior of dual stream was researched by the visualization system and PDPA system was employed to measure the droplet size. Atomization is one of the most important characteristic, so droplet size distributions and SMD are investigated. And the spray characteristics of each injector are also analyzed such as the spray tip penetration, spray angle, and separation angle.
Principle of Design and Performance of the Torque Sensor for a Electrical Power Steering
Lee Eung-Shin ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 121~126
This paper describes the attributes, performance and development status of a high performance capacitive torque sensor intended for use in a electric power steering (EPS) system. The EPS system is composed of torque sensor, ECU, motor, gears and etc. Among the elements, torque sensor in the steering column is one of the core technologies. The new capacitive torque sensor in this paper is developed differently from working principle and mechanical structure compare to extant torque sensors in market and patent. Based on the result of numerical analysis, a experimental equipment is made which is composed of a test jig and a capacitive sensor and validity of numerical analysis and feasibility of the torque sensor are verified.
Vibration Mode and Durability Characteristics of Automotive IDS using Rotary Swaging Process for Incremental Forming
Lim Seong-Joo ; Lee Nak-Kyu ; Lee Chi-Hwan ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 127~133
Rotary swaging is one of the incremental forming process which is a chipless process using the reduction of cross-sections of bars, tubes and wires. The TDS(Tube Drive Shaft) of monobloc used in automotive has been developed by the rotary swaging process. The mechanical characteristics of swaged parts such as the hardness, thickness and roughness are also estimated to conduct experimental analyses of rotary swaging process with the materials of 34Mn5 Furthermore the change in the vibration mode of TDS due to design parameters, which are the tube length, diameter and thickness, has been investigated and analysed. The weight of the TDS product is smaller by about
than that of SDS with the same performance. It could be evidently found that the TDS is designed to be much lighter than SDS (Solid Drive Shaft). This advantage might give some possibility to improve the NVH (Noise-Vibration-Harshness) characteristics. A maximum torque and a total number of torsional repetitions for the TDS is checked and measured to know the torsional intensity and fatigue strength through the static torsion test and torsional durability test, respectively. A total number of the torsional repetitions up to the fracture for the TDS is greater than 250,000 times.
Experimental Analysis of 2-Dimensional Rolling Ftiction Occurred in Semi-Spherical CVT
Kong Jinhyung ; Yoon Youngmin ; Lee Eung-shin ; Lim Wonsik ; Park Yeongi ; Kim Dongjo ; Lee Jangmoo ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 134~141
Semi-Spherical Continuously Variable Transmission(SS-CVT) is the CVT which transmits power by rolling friction between dry metals, and its outstanding advantage is the ability of realizations of neutral, forward and reverse states without relying on any other devices. A spherical shaped variator transmits power and also changes gear ratio where keeping contact with a output disk. The frictional direction to transmit power and the other direction to change gear ratio are perpendicular to each other, so we can describe that two dimensional rolling friction is occurred in the contact point between the variator and the disk. Since magnitudes or relations of the two forces are completely unknown, they were analyzed by the experiments in this study. We determined the variables related with the friction phenomena by the dimensional analysis, and manufactured the SS-CVT test bench which could measure the related variables. Finally, the empirical formula for evaluating the two friction forces was proposed based on the experimental results.
Development of a fatigue life Prediction Program for the Hub Bearing Unit
Hwang Chul-Ha ; Jun Kab-Jin ; Yoon Ji-Won ; Park Tae-Won ; Kim Seung-Hak ; Yi Kyung-Don ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 142~151
To predict the fatigue life of the Hub Bearing Unit(HBU), preload effect and initial axial clearance have to be considered. Various theory and equations for the HBU design used in the passenger car are well developed in many literatures. But most design hand book for bearings or bearing catalogues do not consider the initial axial clearance and preload effect. So there are limits and difficulties to use those data in actual bearing design. To consider the preload effect and initial axial clearance, complex elliptic integrals and nonlinear equations are involved. These equations are difficult to solve during the design process. In order to solve these problems effectively, a program is developed to solve these equations reliably and to help the designer in obtaining the performance data of the HBU such as load distribution, maximum contact stress and fatigue life. The preprocessor of the program helps users to prepare the input data through a dialog box and the post processor makes graphical presentation of the result. In this paper, theoretical and numerical background for the prediction of the fatigue life of the HBU is explained. A simple example is presented to show the usefulness of developed program.
Reliability Analysis and Feilure Mechanisms of Coolant Rubber Hose Materials for Automotive Radiator
Kwak Seung-Bum ; Choi Nak-Sam ; Kang Bong-Sung ; Shin Sei-Moon ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 152~162
Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under the thermal and mechanical loadings. In this study, test analysis was carried out for evaluating the degradation and failure mechanisms of coolant hose materials. Two kinds of EPDM rubber materials applicable to the hoses were adopted: commonly-used ethylene-propylene diene monomer(EPDM) rubbers and EPDM rubbers with high resistance against electro-chemical degradation (ECD). An increase of surface hardness and a large reduction of failure strain were shown due to the formation of oxidation layer for the specimens which had been kept in a high temperature air chamber. Coolant ageing effects took place only by an amount of pure thermal degradation. The specimens degraded by ECD test showed a swelling behavior and a considerable increase in weight on account of the penetration of coolant liquid into the skin and interior of the rubber specimens. The ECD induced material softening as well as drastic reduction in strength and failure strain. However EPDM rubbers designed for high resistance against ECD revealed a large improvement in reduction of failure strain and weight. This study finally established a procedure for reliability analysis and evaluation of the degradation and failure mechanisms of EPDM rubbers used in coolant hoses for automobile radiators.
A Study on the Development of Web-based Expert System for Urban Transit
Kim Hyunjun ; Bae Chulho ; Kim Sungbin ; Lee Hoyong ; Kim Moonhyun ; Suh Myungwon ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 163~170
Urban transit is a complex system that is combined electrically and mechanically, it is necessary to construct maintenance system for securing safety accompanying high-speed driving and maintaining promptly. Expert system is a computer program which uses numerical or non-numerical domain-specific knowledge to solve problems. In this research, we intend to develop the expert system which diagnose failure causes quickly and display measures. For the development of expert system, standardization of failure code classification system and creation of BOM(Bill Of Materials) have been first performed. Through the analysis of failure history and maintenance manuals, knowledge base has been constructed. Also, for retrieving the procedure of failure diagnosis and repair linking with the knowledge base, we have built RBR(Rule Based Reasoning) engine by pattern matching technique and CBR(Case Based Reasoning) engine by similarity search method. This system has been developed based on web to maximize the accessibility.
Bending Performance Evaluation of Reinforced Aluminum Square Tube Beams
Lee Sung-Hyuk ; Choi Nak-Sam ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 171~180
Bending performances of aluminum square tube beams reinforced by aluminum plates under three point bending loads have been evaluated using experimental tests combined with theoretical and finite element analyses. A finite element simulation for the three-point bending test was performed. Basic properties of aluminum materials used for initial input data of the finite element simulation were obtained from the true stress-true strain curves of specimens which had been extracted from the Al tube beams. True stresses were determined from applied loads and cross-sectional area records of a tensile specimen with a rectangular cross-section by real-time photographing, and true strains were obtained from in-situ local elongation measurements of the specimen gage portion by the multi-point scanning laser extensometer. Six kinds of aluminum tube beam specimens adhered by aluminum plates were employed fur the bending test. The bending deformation behaviors up to the maximum load described by the numerical simulation were in good agreement with experimental ones. After passing the maximum load, reinforcing plate was debonded from the aluminum tube beam. An aluminum tube beam strengthened by aluminum plate on the upper web showed an excellent bending capability.
Effects for Coexistent Reductant to NOx Adsorption and Desorption of the NOx Storage Catalyst
Lee, Choon-Hee ; Choi, Byung-Chul ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 181~187
The behavior of fox adsorption and desorption of the NOx storage catalyst supported on Ba additive were studied by the TPA/TPD experiments and reactivity tests. Applying the transient responses and NOx TPA/TPD test by CLD were effective methods to analyze the characteristics of the NOx storage catalyst. NOx variation of the NOx storage catalyst in the lean air/fuel conditions according to temperature was dominated by NOx adsorption and desorption rather than catalytic reduction. The presence of reductants in the lean mixture promoted the NOx desorption at the
higher temperature. The temperatures for maximum NOx conversion with CH4 and
as a rich spike reductant appear around
The Effect of EGR on Exhaust Emissions in a Direct Injection Diesel Engine
Jang, Se-Ho ; Koh, Dae-Kwon ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 188~194
The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments were performed at various engine loads while the EGR rates were set from
The emissions trade-off and combustion of diesel engine are investigated. The brake specific fuel consumption rate is very slightly fluctuated with EGR in the range of experimental conditions. The ignition delay increased with increasing EGR rate. The maximum value of premixed combustion for the rate of heat release is increased with increasing EGR rate. NOx emissions are decreased with increasing EGR rate at high load and high speed. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions.
An Investigation of Con01 Threshold of Vehicle Stability Control System
Chung, Tae-Young ; Yi, Kyong-Su ;
Transactions of the Korean Society of Automotive Engineers, volume 13, issue 5, 2005, Pages 195~201
In conventional Vehicle Stability Control (VSC) System, a control threshold is designed by average driver characteristics. Despite the stabilizing effort, VSC causes redundancy to an expert driver. An advanced VSC which has flexibility on its control property is proposed in this study. By using lateral velocity estimator, a control threshold is determined on side slip angle and angular velocity phase plane. Vehicle planar motion model based sliding controller is modified with respect to various control thresholds. The performance of the proposed VSC algorithm has been investigated by human-in-the-loop simulation using a vehicle simulator. The simulation results show that the control threshold has to be determined with respect to the driver steering characteristics. A VSC with variable control thresholds would provide an improvement compared to a VSC with a constant threshold.