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Welcome to Journal of Automotive Safety and Energy,
汽车安全与节能学报

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  • 2010, Vol. 1 No. 3 Published on:20 September 2010 Previous issue    Next issue
    Research progress of high efficient and clean combustion of automotive gasoline engines
    WANG Jianxin, WANG Zhi
    2010, 1(3):  167-178.  doi:10.3969/j.issn.1674-8484.2010.03.001
    Abstract ( 3223 )   PDF (2466KB) ( 4084 )  
    This paper illustrates the development of Chinese automotive industry and the evolvement of related energy and emission regulations in the decade 2000—2009. It points out that the importance of energy-saving will exceed the problem of pollution. Gasoline direct injection (GDI) and downsizing are the main two approaches for low fuel consumption.The downsizing technology for port fuel injection (PFI) gasoline engines has an advantage of low cost, while the downsizing technology for GDI engines has a better fuel economy. The 2nd generation of GDI engines with stoichiometric combustion has a limited potential of low fuel consumption. The 3rd generation of GDI engine should solve three problems, including knock at high compression ratio, combustion stability in exhaust diluted atmosphere, and particulate matters formation in stratified mixture. Homogeneous charge compression ignition ( HCCI) is an ideal combustion mode for energy-saving and emission reduction of gasoline engines. Gasoline/diesel dual-fuel combustion can reach the highest benefit on fuel consumption, providing the possibility for unification of gasoline engines and diesel engines in the future.
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    Electrification and Intelligence—Technologies that Drive Future Vehicles
    DENG Weiwen
    2010, 1(3):  179-189.  doi:10.3969/j.issn.1674-8484.2010.03.002
    Abstract ( 1900 )   PDF (1993KB) ( 2216 )  
    As automotive industry faces more and more stringent requirements in fuel economy and emissions reduction, electric and electric hybrid vehicles have gained great momentum in recent years. Besides many technical challenges ahead, however, there are market barriers with unaffordable cost and high expectation from consumers. While focus has been on green technology, the resulted vehicle electrification may push automotive industry to an inflection point that revolutionizes the way how vehicles are designed, engineered and built. Electrified vehicle enables intelligent vehicle, which is considered to be one of the ultimate solutions to vehicle safety and performance in general. This paper reviewed the state of the art and challenges in some key areas, in particular, electrical and electronic (E/E) architecture and integrated vehicle controls. The paper concluded that electrification and intelligence is a harmonious combination for vehicles, and the primary drive to the future automotive industry.    
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    Automotive Safety
    Comparison of Pedestrian Accident Scenarios in a Chinese Urban City and in Sweden
    Bing DENG, Zhentai WANG, Jikuang YANG, Chunyu KONG
    2010, 1(3):  190-194.  doi:10.3969/j.issn.1674-8484.2010.03.003
    Abstract ( 1668 )   PDF (1551KB) ( 2092 )  
    To understand the scenarios of vehicle accidents involving pedestrians in Chinese urban traffic, an in-depth accident investigation was conducted in Changsha, China. Accident cases were collected from the Traffic Police Bureau and hospitals from 2001 to 2006. Of the 497 cases collected, there were 446 cases with detailed information from the police, hospital, and retrospective investigations. Fifty-one cases were from on-site investigations. All of the collected cases were documented in a database, called the In-depth Investigation of Vehicle Traffic Accident in Changsha (IVAC). Statistic analysis was conducted using the 497 cases. The results were compared to a study using Swedish TRaffic Accident Data Acquisition (STRADA) data. The fatality rate is more than two times higher in Changsha than in Sweden, while the majority of accidents happened with good lighting conditions and in dry weather for both places. The identified scenarios in Changsha showed a significant difference in distribution compared to that in Sweden.  
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    Optimization design of side airbag based on side impact simulation
    MA Chunsheng, ZHANG Jinhuan, HU Jingyao, HUANG Shilin
    2010, 1(3):  195-199.  doi:10.3969/j.issn.1674-8484.2010.03.004
    Abstract ( 2408 )   PDF (1651KB) ( 1827 )  
    Side airbag plays an important role in improving occupant protection in vehicle side imapct. The whole vehicle finite element (FE) model for side impact was developed with the software of PAM-CRASH by ESI Group. The FE model was validated by comparing the simulation and test results. The optimization method of side airbag parameters was discussed based on simulation. The leakage area, inflator gas flow rate and dimension of side airbag on a passenger car were optimized. Upon the improvement, the C-NCAP (China New Car Assessment Program) rating score of thorax on the car is improved from 0 to 1.8.
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    Detection of driver's drowsiness using facial expression features
    MA Tianyi, CHENG Bo
    2010, 1(3):  200-204.  doi:10.3969/j.issn.1674-8484.2010.03.005
    Abstract ( 1875 )   PDF (1663KB) ( 3225 )  
    A method for detection of drowsiness using visual information of human facial expression was studied and tested. Facial expression features in the state of drowsiness were analyzed based on the characteristics of facial muscle movement and empirical knowledge, then 11 features were characterized. Fatigue driving experiments were conducted using a driving simulator. The features were obtained by the detection of facial markings. Four drowsy expression indexes with significant differences between different drowsy levels have been found, and a discriminating model for drowsiness prediction based on the four indexes has been established, which are eyes open width, eyebrow droop level, corners of the mouth droop level and mouth bending. The results show that the proposed method in this paper could reach an overall correct detection rate of 93%.
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    Crashworthiness design of bottle frame for a hydrogen vehicle
    ZHANG Siliang, ZHU Ping, FENG Qi, WAN Dangshui, ZHOU Qingwei
    2010, 1(3):  205-209.  doi:10.3969/j.issn.1674-8484.2010.03.006
    Abstract ( 1855 )   PDF (1850KB) ( 1936 )  
    The safety design of the hydrogen bottles is an important factor in hydrogen energy vehicle crashworthiness. The frontal impact and the rear impact of a hydrogen vehicle were simulated to investigate the deformation states of a hydrogen bottle framework. The equivalent static forces of impact loads were adopted in the new bottle frame structural optimization process. The material of new frame utilized aluminium alloy and satisfied the bending requirements of different load cases. Then safety of the new frame structure was validated in whole vehicle crashworthiness simulations. The results show that the performances of the new framework improved the vehicle impact safety, and the total mass of the frame is reduced by 27% to realize lightweight structure design.
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    Magnesium Alloy Seat Frame Design Using Sensitivity Analysis
    Younghan YOUN, Wanhee HAN, Kiseong KIM, Kwangsu KIM, Moonyoung CHOI, Beomjin HWANG
    2010, 1(3):  210-213.  doi:10.3969/j.issn.1674-8484.2010.03.007
    Abstract ( 2106 )   PDF (1853KB) ( 3154 )  
     Recently, due to the rapidly increasing fuel price and strict environmental alregulation, light mass vehicle design is one of the major issues in the auto makers. In this study, magnesium alloy seat frame was used to substitute conventional steel seat frame. Despite of higher material cost, the magnesium seat frame can be less mass as well as an excellent vibration absorption capacity. However, the strength of magnesium is lower than that of steel. Design factor on the most stressed parts of the frame were calculated and sensitivity analysis was conducted using orthogonal array table. The orthogonal array models were simulated with LS-Dyna software. The simulated results were analyzed by Taguchi method to find the most influencing design factors on stress and mass. The strength of new designed magnesium alloy seat frame is improved in both strength and stiffness.  
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    Validity of the human neck FE model in low-speed vehicle collisions
    WANG Fang, XIAO Zhi, WAN Xinming, YANG Jikuang
    2010, 1(3):  214-218.  doi:10.3969/j.issn.1674-8484.2010.03.008
    Abstract ( 2108 )   PDF (1712KB) ( 1923 )  
    An FE (finite element) neck model was improved with human like response in vehicle frontal, rear-end and side collisions based on an existing model developed in Hunan University. The model consists of the cervical vertebrae, intervertebral discs, ligaments and muscles that are modeled with various element types. The model was validated against kinematics data from volunteer tests carried out at the Naval Biodynamics Laboratory (NBDL) and Chalmers University of Technology. The results show that the model has good biofidelity with a good agreement with the test results for the main part of the time history of the collision events.
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    Empirical Studies of EGR Enabled Diesel Low Temperature Combustion
    Ming ZHENG, Xiaoye HAN, Graham T. READER
    2010, 1(3):  219-228.  doi:10.3969/j.issn.1674-8484.2010.03.009
    Abstract ( 2357 )   PDF (2509KB) ( 2257 )  
    The use of exhaust gas recirculation (EGR) is an effective way of achieving low temperature combustion (LTC) in diesel engines thereby enabling lower levels of the in-cylinder oxides of nitrogen (NOx) to be produced. In addition the fuel injection strategy used and the control of boost pressure are key aspects in attaining low NOx and soot emissions simultaneously. In the work reported in this paper, experiments were performed on an advanced testing engine platform which allows EGR, fuel injection timing and boost pressure to be precisely controlled and the influence of each parameter on the emissions to be studied independently. The results indicate that within the investigated LTC ranges, the ratio of EGR plays the most effective role in NOx reduction; the injection pressure and boost have a more modest effect on NOx emissions in general. Nevertheless, the increased injection pressure lowers the soot emission across the EGR sweep and the augmented boost reduces the soot significantly from a high soot level. It was also observed that with the high levels of the EGR, both the carbon monoxide and unburned hydrocarbon emissions increase. The effect is attributed to the reduced oxygen concentration and the lowered flame temperature.    
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    Effects of oxygenated fuels on heavy-duty vehicular diesel engine performance
    WANG Xiancheng, SUN Zhixin, HE Mu, HE Xing
    2010, 1(3):  229-234.  doi:10.3969/j.issn.1674-8484.2010.03.010
    Abstract ( 2087 )   PDF (2091KB) ( 1660 )  
    The effects of biodiesel and dimethyl carbonate (DMC) as oxygenate additives on combustion process power, output  and soot emission were investigated on an engine test bench to reduce the soot emission from a heavy duty diesel engine.  The test results show that the pressure curve in cylinder moves backward and the peak value drops when the proportion of the oxygenate fuel increases. The heat release rate curve moves backward either, but the peak value of the heat release increases. The oxygenated fuels decrease particulate matter (PM) emission. The addition of torque at full load biodiesel and DMC leads to less PM but more NOx emission. The engine drops about 5% with volume fraction 20% of biodiesel and 10% of DMC. After adjustment of the maximum fuel feeding, the power using oxygenate blends may be recovered to original value using pure diesel but the soot emission decreased 54.5%.
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    Measurement of  unregulated emissions from a light-duty vehicle fuelled with low-proportion methanol-gasoline blends during cold start
    WANG Zhen, ZHANG Fan, XIAO Jianhua, SHUAI Shijin
    2010, 1(3):  235-241.  doi:10.3969/j.issn.1674-8484.2010.03.011
    Abstract ( 1589 )   PDF (3056KB) ( 1718 )  
    The unregulated emissions were measured on a chassis dynamometer for a light-duty vehicle fuelled with pure gasoline,  fuels with the volume proportions of methanol are 10%, 20% and 30% in the methanol-gasoline blends, before and after conventional three-way catalyst (TWC) using a FTIR spectrometer. The measured results show that the regulated emissions such as CO, HC and NOx of low-proportion (≤30%) methanol- gasoline blends, are the same level as those of pure gasoline under both 25 °C and -7°C cold start. The unregulated emissions, such as unburned methanol and formaldehyde, before the catalyst increase with the increase of methanol proportion. However, the unburned methanol and formaldehyde have very high conversion efficiency and are near zero once the catalyst is lit off.
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    Life cycle assessment of the natural gas-based and coal-based DME as vehicle fuel
    WANG Ying
    2010, 1(3):  242-246.  doi:10.3969/j.issn.1674-8484.2010.03.012
    Abstract ( 2336 )   PDF (1732KB) ( 1737 )  
    The energy consumption, green house gas CO2 and main pollutant emissions per travel distance in life cycle were assessed when using natural gas-based dimethyl ether (DME) and coal–based DME as vehicle fuel. The assessment was based on different production technologies of the natural gas-based DME and coal-based DME and combined with vehicle data. The results show that all energy consumption and pollutant emissions of the natural gas-based DME are lower than those of the coal–based DME, except for CO emission in life cycle. The volatile organic compound (VOC), CO and NOx emissions of the coal–based DME and natural gas-based DME are lower than those of diesel, however, the energy consumption, CO2, particulate matter (PM) and SO2 emissions of DME are higher than those  of diesel. 
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    Simulation on two-stage injection of a heavy-duty diesel engine
    LI Minghai, HOU Chunlin, JIA Xianzhe
    2010, 1(3):  247-252.  doi:10.3969/j.issn.1674-8484.2010.03.013
    Abstract ( 2024 )   PDF (1929KB) ( 2479 )  
    Abstract: An engine cycle simulation model of 16V280ZJ diesel engine with an electronic injection system was established using the software GT-Power. The engine is the power unit of Chinese main railway diesel locomotives. A series of combustion cases of the heavy-duty direct injection (DI) diesel engine were calculated based on typical split injection modes. Simulation parameters are modified based on the comparison with given experimental results. Calculation results effectively demonstrated the effects of different injection velocity, fuel distribution and pulse interval on heat release rate. The injection optimization under multi-injection mode was proposed to lower the emissions and the pressure rise gradient. 
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