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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 22, Issue 7 - Nov 2014
Volume 22, Issue 6 - Sep 2014
Volume 22, Issue 5 - Jul 2014
Volume 22, Issue 4 - May 2014
Volume 22, Issue 3 - Apr 2014
Volume 22, Issue 2 - Mar 2014
Volume 22, Issue 1 - Jan 2014
Selecting the target year
A Study on Effect of Urea-SCR Aftertreatment System upon Exhaust Emissions in a LPG Steam Boiler
Bae, Myung-Whan ; Song, Byung-Ho ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 1~11
DOI : 10.7467/KSAE.2014.22.3.001
The aim of this study is to investigate the effect of SCR reactor on the exhaust emissions characteristics in order to develop a urea-SCR aftertreatment system for reducing
emissions. The experiments are conducted by using a flue tube LPG steam boiler with the urea-SCR aftertreatment system. The urea-SCR aftertreatment system utilizes the ammonia converted from 17% aqueous urea solution injected in front of SCR catalyst as a reducing agent for reducing
emissions. The equivalence ratio, urea injection amount, ammonia slip and
conversion efficiency relative to boiler load are applied to discuss the experimental results. In this experiment, the average equivalence ratio is calculated by changing only the fuel consumption rate while the intake air amount is constantly fixed at
. The average equivalence ratios are 1.38, 1.11, 0.81 and 0.57 when boiler loads are 100, 80, 60 and 40%. The
conversion efficiency is raised with increasing urea injection amount, and
slip is also boosted at the same time. Consequently, the
conversion efficiency relative to boiler load should be examined in combination with urea injection amount and
slip. The results are calculated by 89, 85, 77 and 79% for the boiler loads of 100, 80, 60 and 40%. The appropriate amount of urea injection for the respective boiler load can be not discussed by only
emissions, and should be determined by considering the
slip and reactive activation temperature simultaneously. In this study, the urea amounts of 230, 235, 233 and 231 mg/min are injected at the boiler loads of 100, 80, 60 and 40%, and the final
slips are measured by 8.48, 5.58, 11.97 and 11.34 ppm at the same conditions. THC emission is affected by the SCR reactor under other experimental conditions except 100% engine load, and CO emission at only 40% engine load. The rest of exhaust emissions are not affected by the SCR reactor under all experimental conditions.
A Study of Wheel Guards for Reduction of High Frequency Road Noise
Kim, Hyungyung ; Baik, Hongsun ; Lee, Moonsuk ; Kim, Donghyo ; Kim, Dohyung ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 12~18
DOI : 10.7467/KSAE.2014.22.3.012
This paper describes about the development of new concept's rear wheel guards for the reduction of Road Noise in the passenger vehicle using test. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance test and vehicle test. Through new developing process without vehicle test, Result of road noise will be expected when new concepts and materials of wheel guard is applied into automotive vehicle. As a result of the application of Aimed Helmholtz and Multi-layers concept, this paper classifies the road noise, cost and weight are reduced by new concepts and the solutions are adopted into the 2 cars.
Study on Value Appraisal after the Repair of Cars
Yun, Daekwon ; Lee, Haeteak ; Nam, Ilwoo ; Lee, Heongyu ; Kim, Yonghyeon ; Yun, Jaegon ; Kim, Juyeong ; Ha, Seongyong ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 19~24
DOI : 10.7467/KSAE.2014.22.3.019
This study, the exchange value of the car after the repair, which affects the valuation elements and repair characteristics factors were investigated. Based on this specific accident damaged condition of the car, repair range, repair methods, repair costs, market transactions, taking into account the vehicle's depreciation appraisal method is proposed.
Study on Increase the Production of Materiel(Military Vehicles) based 'Basic Plan for Defense Industry Promotion'
Lee, Bumkoo ; Lee, Sukhee ; Kye, Joongeup ; Lee, Chunbeom ; Jung, Dohyun ; Lee, Cheonsoo ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 25~32
DOI : 10.7467/KSAE.2014.22.3.025
There are many type vehicles in army. They are jeep and truck by basic type. Recently many countries are developing new conceptual military vehicles. And they try for export of those military vehicles to another countries. Also Korea Army is developing military tactical and combat vehicles, and considering various necessary factors for export. But as easing the cold war system tension and reducing of defense budget, decrease in quantity of military vehicles. We think this trend is accelerative. Therefore Government(Military) and defense industry make every effort to increasing sales and productions. In this study, I'll inquire '2013~2017 basic plan for defense industry promotion' for strengthen the power of international competitiveness, and then suggest the increasing method for productions of military vehicles.
Evaluation of Fretting Wear Damage of Electronic Connectors for the Automotive
Jang, SeungGyu ; Kim, Deokhyeon ; Kim, Jinsang ; Choi, SungJong ; Cho, HyunDeog ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 33~41
DOI : 10.7467/KSAE.2014.22.3.033
Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. When two pieces of materials, pressed together by an external static load, are subjected to a transverse cyclic loading or various vibrations, so that one contacting face is relatively displaced cyclically parallel to the other face, wear of the mating surfaces occurs. These fretting damages may be observed in electrical connectors for automotive components, where there are special environments and various vibration conditions. This study aims to evaluate the usefulness of fretting test equipment that was developed for reliability test of electrical connector. Fretting tests were carried out using tin coated connectors and friction force, contact resistance, contact area and roughness of contact region were investigated. The following results that will be helpful to understand the fretting wear mechanism, increase process the contact resistance and contact area were obtained. (1) In the same frequency and slip amplitude, the friction force, roughness and contact area increased rapidly until about
cycles, after which it was slightly changed. (2) In the various frequency and slip amplitude, the contact area increased with slip amplitude and cyclic numbers, but it did not depend on cyclic frequency. (3) The surface roughness of contact region did not depend on the cyclic frequency. From these results, the applicability of the fretting wear test equipment and reliability of connector were discussed.
A Study of GDI+MPI Engine Operation Strategy Focusing on Fuel Economy and Full Load Performance using DOE
Kim, Dowan ; Lee, Sunghwan ; Lim, Jongsuk ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 42~49
DOI : 10.7467/KSAE.2014.22.3.042
The gasoline direct injection (GDI) system is considerably spreading in automotive market due to its advantages. Nevertheless, since GDI system emit higher particle matter (PM) due to its combustion characteristics, it is difficult to meet strengthened emission regulation in near future. For this reason, a combined GDI with MPI system, so-called, dual injection (DUI) system is being investigated as a supplemental measure for the GDI system. This paper focused on power and fuel consumption effect by injection mode strategy of DUI system in part load and idle engine operating condition. In this study, port fuel injectors are installed on 2.4 liters GDI production engine in order to realize DUI system. And, at each injection mode, DOE (design of experiment) method is used to optimize engine control parameters such as dual injection ratio, start of injection timing, end of injection timing, CAM position and so on. As a consequence, DUI mode shows slightly better or equivalent fuel efficiency compared to conventional GDI engine on 9 points fuel economy mode as well as MPI mode shows less fuel consumption than GDI mode during idle operation. Furthermore, DUI system shows improvement potential of maximum 2.0% fuel consumption and 1.1% performance compared to GDI system in WOT operating condition.
Lane Positioning in Highways Based on Road-sign Tracking by Kalman Filter
Lee, Jaehong ; Kim, Hakil ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 50~59
DOI : 10.7467/KSAE.2014.22.3.050
This paper proposes a method of localization of vehicle especially the horizontal position for the purpose of recognizing the driving lane. Through tracking road signs, the relative position between the vehicle and the sign is calculated and the absolute position is obtained using the known information from the regulation for installation. The proposed method uses Kalman filter for road sign tracking and analyzes the motion using the pinhole camera model. In order to classify the road sign, ORB(Oriented fast and Rotated BRIEF) features from the input image and DB are matched. From the absolute position of the vehicle, the driving lane is recognized. The Experiments are performed on videos from the highway driving and the results shows that the proposed method is able to compensate the common GPS localization errors.
Thermal Analysis of a Battery Cooling System with Aluminum Cooling Plates for Hybrid Electric Vehicles and Electric Vehicles
Baek, Seungki ; Park, Sungjin ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 60~67
DOI : 10.7467/KSAE.2014.22.3.060
The battery cells in lithium-ion battery pack assembled with high-capacity and high-power pouch cells, are commonly cooled with thin aluminum cooling plates in contact with the cells. For HEV/EV lithium-ion battery systems assembled with high-capacity, high-power pouch cells, the cells are commonly cooled with thin aluminum cooling plates in contact with the cells. Thin aluminum cooling plates are cooled by cold plate with coolant flow paths. In this study, the effect of the battery cooling system design including aluminum cooling plate thickness and various position of cold plate on the cooling performance are investigated by using finite element methods (FEM). Optimal cooling plate and cold plate design are proposed for improving the uniformity in temperature distributions as well as lowering average temperature for the cells with large capacities based on the simulation results.
Software Fault Injection Test Methodology for the Software Verification of ISO 26262 Standards-based
Lee, Sangho ; Shin, Seunghwan ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 68~74
DOI : 10.7467/KSAE.2014.22.3.068
As the number of ECUs (Electronic control units) are increasing, reliability and functional stability of a software in an ECU is getting more important. Therefore the application of functional safety standards ISO 26262 is making the software more reliable. Software fault injection test (SFIT) is required as a verification technique for the application of ISO 26262. In case of applying SFIT, an artificial error is injected to inspect the vulnerability of the system which is not easily detected during normal operation. In this paper, the basic concept of SFIT will be examined and the application of SIFT based on ISO26262 will be described.
A Study of Valve-train Life Time Estimate in Engine Durability Test (2)
Kim, Jaejin ; Lee, Hwanhui ; Myung, Wanghee ; Min, Byengdu ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 75~80
DOI : 10.7467/KSAE.2014.22.3.075
In previous study, make an attempt to estimate exhaust valve seat and seat-ring wear acceleration factor for engine durability test with measuring and consideration of wear mechanism. But found abnormal initial wear rate in exhaust valve seat-ring. And have to improve exhaust valve seat-ring wear rate for reliability reason, because next GDI/Turbo engine is based on this engine and GDI/Turbo engine have higher combustion pressure and higher thermal load. In this study, Trying to find the cause of abnormal wear factor, improve valve-train durability by change specification & design of parts and verify variant parts for improving durability of valve-train. And then I would like to propose a design guide line of valve-train system in a reliability point of view, besides make a complement of previous study.
Establishing HP/LP-EGR System and Founding Operating Strategy of Low Temperature Combustion Engine to Improve Fuel Consumption
Shin, Seunghyup ; Han, Youngdeok ; Shim, Euijoon ; Kim, Duksang ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 81~89
DOI : 10.7467/KSAE.2014.22.3.081
This study researched on the effect of HP/LP-EGR system to improve fuel consumption of Low Temperature Combustion Engine. Firstly, low temperature combustion engine with HP/LP-EGR system was established using 6.0L wastegate turbocharger HDDI engine. And suppliable EGR rate of the engine was proven to be enough to realize stable low temperature combustion. Then, optimum operating strategy was founded to develop fuel consumption of the engine. Control parameters were HP/LP-EGR valve and IPCV(Intake Pressure Control Valve) duty. Experiments method was that characteristics of the engine were measured and analyzed according to HP/LP-EGR strategies while EGR rate was fixed. Operating range for the strategy were divided into three parts, low load for low temperature combustion, high load for conventional diesel combustion, and transient condition. Finally, with the above strategy of this study, BSFC of the engine was improved about 2% compared to the base engine, and emission level, NOx and PM, met Tier4Final emission regulation.
Strength Evaluation of Pb-free Solder Joints with Artificial Aging Time and Test Temperature
Park, Soyoung ; Yang, Sungmo ; Yu, Hyosun ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 90~96
DOI : 10.7467/KSAE.2014.22.3.090
The conventional SnPb solders were widely used for several decades in the electronic packing system due to the superior mechanical properties such as low melting point, better wettavility and good mechanical fatigue. However, in recent years, owing to adverse effect on the human health and environment, conventional SnPb solders have been replaced by Lead-free solders. In this research, the shear punch(SP) test of Sn-4Ag-(Cu)/Ni pad was performed. Pb-free solder alloys which are the environmentally friendly of the electronic components were performed at
for 100hr~1000hr to artificial aging processing. In order to evaluate the mechanical properties of solder joints, the SP test was conducted at
. As a result, the maximum shear strength of almost the whole specimens was decreased with the increase in aging time and temperature of SP test. The mechanical properties of Sn-4Ag-0.5Cu solder were most excellent in all Pb-free solder which were produced by the SP test at
Optimization of Base Plates and Contact Switches in Trunk Latches
Kim, Kyungnam ; Noh, Yoojeong ; Kim, Donghoon ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 97~104
DOI : 10.7467/KSAE.2014.22.3.097
Automobile trunk latches enable trunks to be opened and closed by a latch mechanism, which can be selectively positioned between a locked condition and an open condition. To maintain structural and electronic performance of the trunk latch, the latch needs to endure impact load that occurs in its open and close motion, and a dynamic mechanism needs to be electronically controled by a contact switch connected with a small DC motor. A base plate, which is the most important component relating to the structural safety, commonly uses a high stiffness material SAPH440-P with high manufacturing cost. In this paper, through structural analysis and optimization, production cost is significantly reduced by replacing SAPH440-P used in some region of the base plate with engineering plastic PBT GF 20%. The optimized contact switch reduces difference between distributed pressures of its two legs, which leads to improve the electronic performance of the trunk latch.
Spray and Flame Characteristics of Waste Cooking Oil Biodiesel and Diesel in a Compression Ignition Diesel Engine Using In-cylinder Visualization
Hwang, Joonsik ; Bae, Choongsik ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 105~113
DOI : 10.7467/KSAE.2014.22.3.105
Spray and combustion process with waste cooking oil (WCO) biodiesel and commercial diesel were analyzed in an optically-accessible single-cylinder compression ignition diesel engine equipped with a high pressure common-rail injection system. Direct imaging method was applied to investigate spray and combustion characteristics. From the mie-scattering results, it was verified that WCO biodiesel had a longer injection delay compared to diesel. Spray tip penetration length of WCO biodiesel was longer and spray angle was narrower than those of diesel due to poor atomization characteristics. In terms of combustion, WCO biodiesel showed later start of combustion, while flame was vanished more rapidly. Analysis of flame luminosity showed that WCO biodiesel combustion had lower intensity and lasted for shorter duration.
Dynamic Temperature Compensation System Development for the Accelerometer with Modified Spline Interpolation (Curve Fitting)
Lee, Hoochang ; Go, Jaedoo ; Yoo, Kwangho ; Kim, Wanil ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 114~122
DOI : 10.7467/KSAE.2014.22.3.114
Sensor fusion is the one of the main research topics. It offers the highly reliable estimation of vehicle movement by processing and mixing several sensor outputs. But unfortunately, every sensor has drift which degrades the performance of sensor. It means a single degraded sensor output may affect whole sensor fusion system. Drift in most research is ideally assumed to be zero because it's usually a nonlinear model and has sample variation. Plus, it's very difficult for the acceleration to separate drift from the output signal since it contains many contributors such as vehicle acceleration, slope angle, pitch angle, surface condition and so on. In this paper, modified spline interpolation is introduced as a dynamic temperature compensation method covering sample variation. Using the last known output and the first initial output is suggested to build and update compensation factor. When the system has more compensation data, the system will have better performance of compensated output because of the regression compensation model. The performance of the dynamic temperature compensation system is evaluated by measuring offset drift between with and without the compensation.
Development of a Monitoring and Verification Tool for Sensor Fusion
Kim, Hyunwoo ; Shin, Seunghwan ; Bae, Sangjin ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 123~129
DOI : 10.7467/KSAE.2014.22.3.123
SCC (Smart Cruise Control) and AEBS (Autonomous Emergency Braking System) are using various types of sensors data, so it is important to consider about sensor data reliability. In this paper, data from radar and vision sensor is fused by applying a Bayesian sensor fusion technique to improve the reliability of sensors data. Then, it presents a sensor fusion verification tool developed to monitor acquired sensors data and to verify sensor fusion results, efficiently. A parallel computing method was applied to reduce verification time and a series of simulation results of this method are discussed in detail.
Rack Force Estimation Method using a Tire Mesh Model
Kim, Minjun ; Chang, Sehyun ; Lee, Byungrim ; Park, Youngdae ; Cho, Hyunseok ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 130~135
DOI : 10.7467/KSAE.2014.22.3.130
In this paper, a new estimation method is proposed to calculate steering rack axial force using a 3 dimensional tire mesh model when a car is standing on the road. This model is established by considering changes of camber angle and contact patch between the tires and the ground according to steering angle. The steering rack bar axial force is estimated based on the static equilibrium equations of forces and moments. A tire friction force is supposed to act on the center point of the contact patch, and the proportional coefficient of friction depending on contact patch is suggested. Using the proposed estimation method, rack axial force sensitivity analysis is evaluated according to changes of suspension geometry. Then optimal motor power of Motor Driven Power Steering(MDPS) is evaluated using suggested rack forces.
Characteristics of Heart Rate Variability Derived from ECG during the Driver's Wake and Sleep States
Kim, Min Soo ; Kim, Yoon Nyun ; Heo, Yun Seok ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 136~142
DOI : 10.7467/KSAE.2014.22.3.136
Distinct features in heart rate signals during the driver's wake and sleep states could provide an initiative for the development of a safe driving systems such as drowsiness detecting sensor in a smart wheel. We measured ECG from health subjects (
in age) during the wake and drowsiness states. The proposed method is able to detect R waves and R-R interval calculation in the ECG even when the signal includes in abnormal signals. Heart rate variability(HRV) was investigated for the time domain and frequency domains. The STD HR(0.029), NN50(0.044) and VLF power(0.0018) of the RR interval series of the subjects were significantly different from those of the control group (p < 0.05). In conclusion, there are changes in heart rate from wake to drowsiness that are potentially to be detected. The results in our study could be useful for the development of drowsiness detection sensors for effective real-time monitoring.
The Effect of EMC by Metal Cover and Noise Reduction Method
Yun, Sangwon ; Park, Chuleui ; Lee, Chanho ; Kim, Sehyun ; Yang, Manyoung ; Kim, Dongsik ; Yoo, Jiyoon ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 143~147
DOI : 10.7467/KSAE.2014.22.3.143
The ECU which is operating inductive actuator like motor or solenoid should be designed with considering the heat removal performance and the EMC performance. In most cases, these two performances are trade-off. Especially, the metal cover with plastic housing for improving heat removal performance can affect EMC performance by coupling the noise source to harness cable and connector. Therefore, after analyzing the EMC effectiveness of the metal cover, countermeasures for EMC noise reduction should be established. In this paper, by simulating and testing of AHB Gen3 ECU, the influence of the metal cover to EMC performance is analyzed. And based on this result, we propose solutions for EMC noise reduction.
Development and Application of High Energy Ignition System Using Plasma
Kang, Hyehyun ; Choi, Duwon ; Park, Jinil ; Lee, Jonghwa ; Park, Kyoungseok ; Ahn, Jongyoung ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 148~156
DOI : 10.7467/KSAE.2014.22.3.148
This study is a follow-up study of "Development of Plasma Ignition System" was presented at the 2013 KSAE spring conference. This study compares lean limit of conventional ignition system with plasma ignition system on constant volume combustion test & Engine Combustion test.
A Study on Women's Specific Package Factors for Compact Vehicle
Nam, Jongyong ; Lee, Yong ; Kim, Taeyub ; Park, Inseong ; Lee, Hotaek ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 157~165
DOI : 10.7467/KSAE.2014.22.3.157
To develop a compact vehicle for women, the most important areas are 'behavioral characteristics, life style and driving posture'. Static AM95%ile manikin is used for package guideline. Since women's characteristics and sitting position are different from men, however, the guideline cannot satisfy women drivers. Therefore, the goal of this study is to make the database with dynamic women's driving posture and behavioral characteristics at compact vehicle. Research process will be made as follows. Firstly, through the online/offline survey and statistic analysis, lifestyle and behavioral characteristics (discomfort elements) of women are extracted. Secondly, the author performs scenario test to acquire the discomfort value of driving situation and life style. 3D models of women's manikin and driving posture were created by CATIA HUMAN. The 3D models are used for the purpose of analyzing women's driving posture. Finally, with the ANOVA result and comparison between real driving posture and package guidelines, the author is able to suggest the main issue for women drivers.
Study on Electric and Magnetic Characteristics of Engine Oil in Transport Truck
Kim, Man Jae ; Lee, Woo Sin ; Jung, Jong Hoon ; Lee, Sang Hoon ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 166~170
DOI : 10.7467/KSAE.2014.22.3.166
In this paper, we investigate the electric and magnetic properties of the engine oil, and estimate its changing time in transport truck. The four diesel trucks are selected, and the capacitance and inductance are investigated with parallel capacitor and induction coil, respectively. The measured capacitance gradually increases up to 10,000~14,000 km due to the activation of antioxidant, and then decreasing phenomena happen. The inductance decreases and the saturation began in 10,000~14,000 km range. Although the behavior of inductance is different from that of capacitance, but changing points are similar. From those results, we can estimate the changing time of engine oil is around 10,000~14,000 km and the inductance can be used for monitoring of engine oil in transport trucks.
A Numerical Study on the Optimization of Urea Solution Injection to Maximize Conversion Efficiency of NH
Moon, Seongjoon ; Jo, Nakwon ; Oh, Sedoo ; Jeong, Soojin ; Park, Kyoungwoo ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 171~178
DOI : 10.7467/KSAE.2014.22.3.171
From now on, in order to meet more stringer diesel emission standard, diesel vehicle should be equipped with emission after-treatment devices as NOx reduction catalyst and particulate filters. Urea-SCR is being developed as the most efficient method of reducing NOx emissions in the after-treatment devices of diesel engines, and recent studies have begun to mount the urea-SCR device for diesel passenger cars and light duty vehicles. That is because their operational characteristics are quite different from heavy duty vehicles, urea solution injection should be changed with other conditions. Therefore, the number and diameter of the nozzle, injection directions, mounting positions in front of the catalytic converter are important design factors. In this study, major design parameters concerning urea solution injection in front of SCR are optimized by using a CFD analysis and Taguchi method. The computational prediction of internal flow and spray characteristics in front of SCR was carried out by using STAR-CCM+7.06 code that used to evaluate
UI). The design parameters are optimized by using the
orthogonal array and small-the-better characteristics of the Taguchi method. As a result, the optimal values are confirmed to be valid in 95% confidence and 5% significance level through analysis of variance(ANOVA). The compared maximize
UI and activation time(
UI 0.82) are numerically confirmed that the optimal model provides better conversion efficiency of
. In addition, we propose a method to minimize wall-wetting around the urea injector in order to prevent injector blocks caused by solid urea loading. Consequently, the thickness reduction of fluid film in front of mixer is numerically confirmed through the mounting mixer and correcting injection direction by using the trial and error method.
Effect of Coolant Flow Characteristics in Cooling Plates on the Performance of HEV/EV Battery Cooling Systems
Oh, Hyunjong ; Park, Sungjin ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 179~185
DOI : 10.7467/KSAE.2014.22.3.179
Average temperature and temperature uniformity in a battery cell are the important criteria of the thermal management of the battery pack for hybrid electric vehicles and electric vehicles (HEVs and EVs) because high power with large size cell is used for the battery pack. Thus, liquid cooling system is generally applied for the HEV/EV battery pack. The liquid cooling system is made of multiple cooling plates with coolant flow paths. The cooling plates are inserted between the battery cells to reject the heat from batteries to coolant. In this study, the cooling plate with U-shaped coolant flow paths is considered to evaluate the effects of coolant flow condition on the cooling performance of the system. The counter flow and parallel flow set up is compared and the effect of flow rate is evaluated using CFD tool (FLUENT). The number of counter-flows and flow rate are changed and the effect on the cooling performance including average temperature, differential temperature, and standard deviation of temperature are investigated. The results show that the parallel flow has better cooling performance compared with counter flow and it is also found that the coolant flow rate should be chosen with the consideration of trade-off between the cooling performance and pressure drop.
Effects of EPS Assist Torque on On-center Steering Feel Indices
Kim, Sang Sup ; Kyeong, Jin Sil ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 186~193
DOI : 10.7467/KSAE.2014.22.3.186
On-center handling feel indices are the important numerical factors that meaning performance of manuability and stability felt by drivers. They should be considered to suspension design. The major factor that affect to these indices is the shape of assist torque curve. This paper presents the variables that meaning the shape of the assist torque curve and analyze the effect of each variables. And using interaction formulas, it is proposed that the method to extract the variables that satisfy the goal indices. The result of simulation that applied assist torque curve extracted by the method demonstrate the capability of this method with error under 8%.
Steering Axis Analysis of Multi-link Suspensions with Bushing Compliance
Kim, Sang Sup ; Kim, Seong Hun ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 194~202
DOI : 10.7467/KSAE.2014.22.3.194
Steering axis of suspensions is an important factor that affects ride and handling quality in the vehicle chassis development. Macpherson strut and double wishbone's steering axis are defined geometrically, but multi-link suspensions can not be geometrically analyzed. In this case instant axis theory is commonly used to find a steering axis. Since the steering axis is moving with varying caster and kingpin inclination angle, this method approximately corresponds with exact solution. In this paper, we propose a velocity analysis method to find a pure rotational axis of the wheel relative to suspension arms, that is exact solution of the steering axis. This paper extends the method to analyze the steering axis of multi-link suspensions with bushing compliance. The analysis results applied to double wishbone and multi-link suspensions demonstrate validity and accuracy of the proposed method.
Robust Rear Center-Hinge Bracket Optimization Based on Taguchi Method
Jung, Sebin ; Kim, Minho ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 203~209
DOI : 10.7467/KSAE.2014.22.3.203
The rear center-hinge bracket is designed for supporting and folding the rear-seat backrest. This bracket needs to be strong enough to be able to rigidly hold the rear-seat backrest and to withstand luggage loads from the car trunk that are generated when a vehicle is driving on the roads. Particularly, current accident studies report that many serious occupant injuries occurred when the rear-seat back easily folded inward toward the car interior, driven by the luggage loads in the trunk. Given this fact, the robust design of the rear center-hinge bracket that mainly supports the rear backrest has become more important for providing customer safety and preventing high warranty and durability problems. However, none of the studies have emphasized its significant role and considered its robust optimization. Therefore, this paper presents how the hinge-bracket design is optimized based on an application of the finite-element method coupled with the parameter design using Taguchi's design experiment. Finally, Taguchi method's application optimizes a robust center-hinge bracket that shows more rigid performance although it has lighter weight and thinner thickness.
Characteristics of the In-cylinder Flow and Fuel Behavior with Respect to Engine Temperature Condition in the MPI Dual Injection Engine
Lee, Seung Yeob ; Chung, Jin Taek ; Park, Young Joon ; Yu, Chul Ho ; Kim, Woo Tae ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 210~219
DOI : 10.7467/KSAE.2014.22.3.210
The MPI dual injection engine can enhance the fuel efficiency and engine power. By using one injector per one intake port, MPI dual injection engine has an excellent fuel atomization and targeting injection. As the basic research for the MPI Dual injection engine design, this research was investigated in order to understand the characteristic of the in-cylinder flow and fuel behavior according to engine temperature condition and the fuel type in the MPI dual injection engines. The 3D unsteady CFD simulation for the MPI Dual injection engine was performed using STAR-CD. The engine operating condition was 2,000 rpm/WOT. The parameters for this study were fuel types, fuel temperatures and wall temperatures. As a result, the intake air amount, evaporated fuel in the cylinder and the fuel film on the wall were presented according to parameters that depend on the fuel properties and engine wall temperature. Also, the results were influenced by in-cylinder flow such as the intake flow, back flow and so on.
Synchronous Interfusion of the Compensatory Filters Based on Multi-rate Sensors for the Control of the Autonomous Vehicle
Bak, Jeong-Hyeon ; Lee, Kwanghee ; Lee, Chul-Hee ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 220~227
DOI : 10.7467/KSAE.2014.22.3.220
This paper presents about multi-rate sensors' synchronization and filter fusion via a sigmoid function of the Kalman filter. To synchronize multi-rate sensors, the estimation states of the Kalman filter is modified. A specific matrix that makes the filter choose sensor values only updated is multiplied to measurement matrix. For the filter that has weak points on some criteria, filter fusion is suggested by using sigmoid function. Modified kalman filter is tested with practical case. A sigmoid function was designed for the test and the performance of the modified function is estimated with respect to conventional Kalman filter. Unscented Kalman filter is used to the base filter of the suggested filter because of its stability.
Modeling of Engine Intake Pressure for Predicting Braking Performance Affected by Altitude
An, Kwangman ; Lee, Jisuk ; Park, Jinil ; Lee, Jonghwa ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 228~233
DOI : 10.7467/KSAE.2014.22.3.228
Reduction of the atmospheric pressure in high altitude affects brake booster system which was operated by the difference between the intake pressure and the atmospheric pressure. So, braking system can not stably perform due to decrease of brake boost pressure. In this study, effects of altitude change on engine intake pressure was analyzed by prediction model of engine intake pressure which was studied previously. And engine intake pressure was simulated by simulation model in various driving conditions and environmental conditions.
Driving Concept Development for Elderly Drivers
Jung, Sebin ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 234~240
DOI : 10.7467/KSAE.2014.22.3.234
Driving-related injuries associated with elderly drivers are on the rise, although the overall rate of driving-related injuries has decreased. To determine the causes of this trend, we researched existing vehicle systems that use different sensors and signals to promote safe driving. We found that although the systems alert drivers to potential collisions and assist them in finding a location easily, they were created by people who rarely use the systems in their daily lives. For the most part, they're not created by people with driving difficulties caused by health problems, which in turn often afflict the elderly. To address this issue, we analyzed the drawbacks of the current systems and used a focus group of people with body conditions that have declined due to age to discover the problems they encounter while driving. With the focus group, we used diverse research activities, such as observation and interview to demonstrate how new system concepts could be developed for the elderly. Finally, we propose that adequate system concepts for the elderly would improve driving safety and provide a more enjoyable driving environment for this population.
Path Planning for Static Obstacle Avoidance: ADAM III
Choi, Heejae ; Song, Bongsob ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 241~249
DOI : 10.7467/KSAE.2014.22.3.241
This paper presents a path planning algorithm of an autonomous vehicle (ADAM III) for collision avoidance in the presence of multiple obstacles. Under the requirements that a low-cost GPS is used and its computation should be completed with a sampling time of sub-second, heading angle estimation is proposed to improve performance degradation of its measurement and a hierarchical structure for path planning is used. Once it is decided that obstacle avoidance is necessary, the path planning consists in three steps: waypoint generation, trajectory candidate generation, and trajectory selection. While the waypoints and the corresponding trajectory candidates are generated based on position of obstacles, the final desired trajectory is determined with considerations of kinematic constraints as well as an optimal condition in a term of lateral deviation. Finally the proposed algorithm was validated experimentally through field tests and its demonstration was performed in Autonomous Vehicle Competition (AVC) 2013.
A Study of Torque Vectoring Application in Electric Vehicle for Driving Stability Performance Evaluation
Yi, JongHyun ; Lee, Kyungha ; Kim, Ilho ; Jeong, Deok-Woo ; Heo, Seung-Jin ;
Transactions of the Korean Society of Automotive Engineers, volume 22, issue 3, 2014, Pages 250~256
DOI : 10.7467/KSAE.2014.22.3.250
EV(Electric Vehicle) has many benefits such as prevention of global warming and so on. But due to driving source changing from combustion engine to battery and e-motor, new R&D difficulties have arisen which changing of desired vehicle performance and multidisciplinary design constraints by means of strong coupled multi-physics domain problems. Additionally, dynamics performances of EV becomes more important due to increasing customer's demands and expectations for EV in compare with internal combustion engine vehicle. In this paper suggests model based development platform of EV through integrated simulation environment for improving analyse & design accuracy in order to solve multi-physics problem. This simulation environment is integrated by three following specialized simulation tools IPG CarMaker, AVL Cruise, DYMOLA that adapted to each purpose. Furthermore, control algorithm of TV(Torque Vectoring) system is developed using independent driven e-motor at rear wheels for improving handling performance of EV. TV control algorithm and its improved vehicle performances are evaluated by numerical simulation from standard test methods.