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International Journal of Automotive Technology
Korean Society of Automotive Engineers (KSAE)
International Journal of Automotive Technology

Korean Society of Automotive Engineers (KSAE)

1229-9138

International Journal of Automotive Technology/Journal International Journal of Automotive TechnologyEISCIISTP
正式出版
收录年代

    Performance Prediction of Engine Coolant Circulation Type Melting System of Frozen Urea: Effect of Heating Coil Design

    Jeong, SeokhoonKim, HyunjunKwon, OhyunPark, Eunyong...
    7页
    查看更多>>摘要：Designing a urea heating coil by repeating a urea melting experiment is a very time-consuming and cost-taking task. In this paper, insight on how to design the heating coil of engine coolant type urea tank is provided from numerical analysis. The numerical analysis conditions used in this study were brought from the EPA test procedure, and numerical analysis results are compared with experiment results to investigate reliability of the numerical analysis. The case studies comparing the melted amount of urea of six different urea heating coils are carried out and a following conclusion is reached. Increasing the occupied volume of the urea heating coil by enlarging pitch distance of the heating coil can improve the performance of melting of frozen urea.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Multi-stage Ignition System With Self-adaptive Control for Lean Combustion in SI Natural Gas Engine

    Tang, Hui SongWu, Chang Shui
    11页
    查看更多>>摘要：Due to the wide application of SI engines, there is an urgent need to improve their thermal efficiency. Lean combustion technology is an advanced technology that effectively improves the efficiency of ignition engines. However, the change of the combustion cycle deteriorates with the increase of the dilution of the mixture, so reducing the influence of the combustion variations during lean combustion is the key issue to increase the excess air ratio. In the lean limit combustion, the combustion stability and heat release rate can be improved by choosing the appropriate spark advance and spark discharge energy. In this paper, a self-adaptive multi-stage ignition system is designed, which can realize the control of adaptive ignition energy and SA according to the real-time operating condition. Through experiments, the effects of ignition energy and SA on the cycle-to-cycle variations are analyzed, and it is verified that the system effectively improves the lean combustion thermal efficiency and can ensure the combustion stability under lean combustion.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Numerical Study on the Design of Air Cooled Battery Thermal Management System for Eco-friendly Vehicles

    Huluka, Alemayehu WakjiraKim, Chul-Ho
    10页
    查看更多>>摘要：Electric vehicles are a clean energy transportation option recently emerged as an alternative to the conventional engine powered vehicles. These vehicles are using Lithium ion battery as energy storage for their propulsion because of its energy density. Due to the chemical reaction of battery elements and internal resistance, the battery releases heat during charging and discharging. Unless this heat is controlled to be within the battery optimum operating temperature, the battery performance and life will be seriously affected. This paper is dedicated to conduct fundamental studies on the battery cooling. A three dimensional numerical analysis is made using PHOENICS version 2018. Cylindrical type battery cell is used in this study. The study gives insight to thermal response, flow field and temperature profiles in the battery module with air flow direction relative to battery cell orientation and cell arrangement. Temperature variation along the flow, and transverse direction of the battery pack is discussed. With a 5 mm inter cell spacing and symmetric arrangement, maximum cell to cell temperature variation in the axial flow type is observed to be 0.2 degrees C, while in the radial flow type about 3.5 degrees C for same arrangement. Quantitative and qualitative results obtained from the numerical test are presented. Furthermore, this work is believed to contribute to the improvement of battery air cooling system design in such a way the associated cost and efficiency is compromised.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Pedestrian Collision Avoidance Using Deep Reinforcement Learning

    Rafiei, AlirezaFasakhodi, Amirhossein OliaeiHajati, Farshid
    10页
    查看更多>>摘要：The use of intelligent systems to prevent accidents and safety enhancement in vehicles is becoming a requirement. Besides, the development of autonomous cars is progressing every day. One of the main challenges in transportation is the high mortality rate of vehicles colliding with pedestrians. This issue becomes severe due to various and abnormal situations. This paper proposes a new intelligent algorithm for pedestrian collision avoidance based on deep reinforcement learning. A deep Q-network (DQN) is designed to discover an optimal driving policy for pedestrian collision avoidance in diverse environments and conditions. The algorithm interacts with the vehicle and the pedestrian agents and uses a specific reward function to train the model. We have used Car Learning to Act (CARLA), an open-source autonomous driving simulator, for training and verifying the model in various conditions. Applying the proposed algorithm to a simulated environment reduces vehicles and pedestrians' collision by about 64 %, depending on the environment. Our findings offer an early-warning solution to mitigate the risk of a crash of vehicles and pedestrians in the real world.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Analysis and Optimization of Beam Opening Angle of Torsion Beam Suspension to Improve Frequency Response Characteristics of Whole Vehicle

    Gao, JinHan, Peifeng
    18页
    查看更多>>摘要：Taking torsion beam suspension as the research object, the kinematics characteristics of the suspension are analyzed, and the expressions of the wheel alignment parameters are established. It also explains why the changes in the suspension's roll stiffness and the load transfer between the left and right wheels affect the handling stability. According to the established 3-DOF vehicle dynamic model, the transfer functions of the vehicle response index relative to the steering wheel angle are deduced. The rigid-flexible coupling model of torsion beam suspension and the multi-body dynamics model of the vehicle are established. The influence of the opening angle on the suspension performance and the mechanism are analyzed through simulation. Based on swept-sine input simulation, the change law of the transient response index in low and high frequency, and the relationship between the opening angle and the transient stability index are obtained. Finally, the opening angle is taken as the optimization variable, and the transient response index of the vehicle at 0.5 Hz under swept-sine input simulation is taken as the optimization objective through NSGA-II algorithm. When the opening angle is about 85 degrees, the vehicle's transient response index reaches the optimal, which is the optimal opening angle.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Spray Development Process Utilizing a Multi-Hole GDI Injector with Different Spray Hole Lengths and Step Hole Diameters

    Park, JeonghwanPark, Sungwook
    9页
    查看更多>>摘要：This study focused on the spray development process via spray visualization experiment using different nozzle shape. Specifically, the spray penetration and initial spray angle were determined by high-speed camera and Long distance microscope (LDM) visualization system. Additionally, a sheet beam Nd-YAG laser was used to obtain the spray pattern. The experimental results showed that an injector with a step hole of smaller diameter has a narrower spray angle at the initial injection stage and longer spray penetration compared to an injector with a step hole of larger diameter. In addition, spray penetration was greater for a shorter spray hole length. These results demonstrate that the structure of the step and spray hole for a multi-hole Gasoline direct injection (GDI) injector is an important parameter in the spray development process. Because the air flow path could be changed according to the spray and step hole dimensions. Moreover, CFD simulation was conducted by Star-CCM+ 13.06 in order to find out about air recirculation phenomenon.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    High-load Expansion by Varying Effective Compression Ratio Using Variable Valve Duration System under Dual-fuel Premixed Compression Ignition

    Lim, DonghyunShin, HyungjinChu, SanghyunLee, Jeongwoo...
    8页
    查看更多>>摘要：In this study, a high-load expansion strategy was investigated by varying the effective compression ratio (CR) using the variable valve duration (VVD) method during combustion in a gasoline/diesel dual-fuel premixed compression ignition engine. The effective CR was varied from 15.0 to 10.6 via the retardation of the intake valve closing timing (IVC) at 1,500 rpm. With respect to optimization, the diesel injection timing, fuel ratio, and exhaust gas recirculation (EGR) rate were adjusted for each optimized condition. The limitations were the maximum pressure rise rate (below 10 bar/deg) and in-cylinder pressure (below 150 bar) with NOx < 40 ppm and soot < 0.2 FSN. The results emphasized that when the effective CR was 12.7, the maximum load increased by 10.5 % (gIMEP from 13.3 to 14.7 bar) compared with that at a CR of 15.0. Although the decrease in CR resulted in a gross thermal efficiency loss, the difference was negligible (from 45.9 to 45.5 %). The main reason for high-load expansion was the increase in intake air volume under the same intake pressure upon lowering the CR and the margin for the maximum in-cylinder pressure. From this result, it can be concluded that the Miller cycle is useful for the expansion of high load ranges in premixed combustion systems.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Impact Overlaps on Occupant Lower Limb Injuries under Car Frontal Crash

    Xiao, SenShi, XueweiSun, XiuxiuZhang, Hao...
    7页
    查看更多>>摘要：The lower extremity is one of the most difficult parts to protect in a car collision. The purpose of this paper is to determine the injury characteristics of the lower extremities under frontal collisions with different overlaps. The test device for human occupant restraint (THOR) 50th finite element model was used to conduct three collision simulations based on the actual load environment. Then the kinematic responses of the lower extremity like axial force/moment of the femur, and tibial index in frontal collision were compared to analyse the relationship between lower extremity injury and collision overlaps. Results show that the kinematics of the occupant's lower limbs is sensitive to collision overlap rates. As the collision overlap increased, the amplitude of lower limb displacement would decrease. The most serious femoral injury occurred in the 25 % overlap frontal collision. Especially in the left middle femur, the peak axial force reaches 3.2 kN and the peak bending moment reaches 108 Nm. In a full-frontal collision, the risk of femoral injury is serious, which may relate the great vehicle acceleration. The tibia index is not significantly different in frontal collisions with overlap rates. This study can provide a reference for the study of lower extremity injury mechanism during frontal collision.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Regenerative Braking Control Strategies with Fixed Ratio and Variable Ratio Braking Forces Optimization Distribution for Electric Vehicles during Downhill Process

    Li, XiangjieZhang, XiangwenWang, Yangxiong
    15页
    查看更多>>摘要：The regenerative braking system can recover the braking energy to extend the mileage of electric vehicles, however, recovering more energy and ensuring the braking stability are conflicted each other. In addition, during the downhill process, the road slope angle has a great influence on braking stability and braking energy recovery efficiency. In this study, considered the road slope angle estimation, the fixed ratio and variable ratio braking forces optimization distribution methods are designed based on the vehicle stability demand, and the regenerative braking control strategies are proposed to recovery more energy with the designed braking forces distribution methods. In this way, the conflict between braking stability and energy recovery can be solved. In order to verify the strategies, the system model, road condition and driving intentions are established on dSPACE's ASM and Simulink co-simulation platform, and the regenerative braking control strategies are realized and simulated on different slope roads and UDDS urban road cycle conditions. The results show that the estimated error of the road slope angle can be within 0.4 degrees. The two strategies can ensure the vehicle braking stability. The recovered energy increases obviously with the increase of slope angle. The optimization distribution methods have a better energy recovery effect than the unoptimized methods, the optimal variable ratio method increases the recovered energy by up to 3.67 %, and the optimal fixed ratio method increases the recovered energy by up to 3.38 %.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae

    Valve Optimization with System-fluid-magnetic Co-simulation and Design of Experiments

    Oh, U.Nonaka, NorihikoIshimoto, Jun
    10页
    查看更多>>摘要：This paper presents the design optimization results for the anchor shape of the solenoid part of a flow-rate control valve by executing the design of experiments (DOE) for developing a quieter high-pressure pump. The impact of the noise level increases with an increase to the valve impingement velocity, so the objective of the design optimization is to reduce the valve impingement velocity. In this study, we executed the DOE to simulate two models of the anchor/core of the solenoid part of a flow-rate control valve, grooved and oblique, to optimize the anchor shape by varying four design parameters and then compared them with the original anchor/core design. We evaluated the anchor impingement velocity results with regard to the factor effects and clarified the relation between the velocity and the design parameters.
      原文链接:
    • NSTL
    • Korean Soc Automotive Engineers-Ksae