Recently diesel engines are required to reduce fuel consumption further. Combined cycle is one of the heat recovery technologies and has already applied to practical use in large scale power plants. In this study, the possibility of the Diesel-Rankine combined cycle, which combines diesel cycle with Rankine cycle with superheating was predictively investigated. As a result, it found that Diesel-Rankine combined cycle has a potential to improve the brake specific fuel consumption for about 2.6-3.0 % at a full load condition, whichever water, methanol, toluene or HCFC-123 is utilized as a working fluid of Rankine cycle with superheating.

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For diesel engine, more lower compression ratio has been demanded to improve fuel consumption, output power and emission recently. However, low compression ratio engine may have some issues in combustion instability under cold start condition. In this study, the validity of the multi pilot injection which was combustion instability improvement methods of diesel engine was considered using the combustion analysis by cylinder pressure sensor with glow plug function and CFD simulation which was improved to apply under cold start condition. As a result, it was found that controlling the equivalence ratio and temperature surrounding glow plug appropriately by multi pilot injection was contributing to the improvement of combustion stability under cold start condition.

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Diesel engines of low compression ratio have issues of white smoke and combustion instability under cold start conditions. TI(Time-scale Interaction) combustion model applied cold start conditions in order to resolve those issues. TI combustion model has been developed for simulating combustion phenomena with high accuracy from premixed charged combustion to diffusion combustion. This model is based on a reasonable combustion mode, taking into account the characteristic time scale of chemical reactions and turbulence eddy break-up. In addition, parameters of the ignition model and computational grids near glow-plug were improved to apply under cold start conditions. Comparisons of measured and calculated heat release patterns show good agreement under cold conditions. It was shown by application of TI combustion model under cold start conditions that the fuel reaction near the glow plug is significant for ignition.

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Particle formation and oxidation processes in diesel combustion are investigated in the point of view of instantaneous and spatial characteristics by using a CFD code which accounts for finite-rate elementary chemical reactions coupled with the phenomenological multiple steps soot model. Particle formation and oxidation processes derived from CFD simulation is compared with observation result with laser techniques firstly, then, influences on the process in different fuel injection conditions are analyzed.

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In this study, degradation of heat transfer performance of multi-tube type EGR-cooler, which had spirally-grooved flow channel for exhaust gas, was evaluated by JE05 test mode. Cold start and hot start tests were conducted and deposition thickness after each test was measured. EGR-Cooler after cold start tests showed 10% degradation of thermal ratio and slight change of pressure loss. On the other hand, EGR-Cooler after hot start tests showed 37% degradation of thermal ratio and reduction of pressure loss. Deference of these results was assumed to be due to bulk density of deposit layer on heat transfer wall.

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The durability of hexagonal cell and square cell SiC diesel particulate filters (DPFs) were evaluated in the mechanical strength test and the drop to idle test (DTIT test). Results show that the b-axis and c-axis mechanical strengths of the hexagonal cell DPF are almost equal, and the values of Young’s modulus of hexagonal cell DPF are lower compared with those of the square cell DPF. In addition, if the same soot amount is burned in drop to idle test, the difference between minimum and maximum temperatures inside hexagonal cell DPF is smaller than that of square cell DPF.

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Cold weather operation has been a major issue for fuel cell vehicles (FCV). To counteract the effects of low temperatures on FCV operation, an approach for rapid warm-up operation based on concentration overvoltage increase and conversion efficiency decrease by limiting oxygen or hydrogen supply was adopted. In order to suppress increases in waste hydrogen concentration due to pumping hydrogen during rapid warm-up, dilution control using bypass air and reduction of concentration overvoltage by a minimum voltage guard were implemented. These approaches effectively control waste heat generation and suppress waste hydrogen concentrations during cold start and warm-up. These developments were incorporated into the 2008 Toyota FCHV-adv and it was confirmed that the rapid warm-up operation strategy allowed the FCHV-adv to be successfully and repeatedly started at -30℃.

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“G-Vectoring Control”is an automatic longitudinal acceleration control method that responds to vehicle lateral jerk caused by the driver’s steering manoeuvres, and improves vehicle’s agility and stability. This method can be realized not only by electrically controlled brake actuators, but also by electric motors on hybrid electrical vehicles or battery electrical vehicles. In this paper, we formulate the amount of regenerated energy during G-Vectoring deceleration control by an electric motor theoretically. We also estimate the peak motor power during braking by fixing the turning trajectory as clothoid curve. Using test vehicle with an electric motor, the accuracy of the theoretical values is evaluated.

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In-wheel motor is one of the methods to increase the driving efficiency. And direct drive can realize the highest mechanical efficiency because of its simple structure. Direct drive has no gears between the motors and the wheels. Therefore the parts that have mechanical loss are the bearing and the seals. The frictions of the parts are tested and the new method of parts layout is also suggested. The friction of the direct drive motors is 30.4N with the tires whose radius is 0.3 meters. And electric consumption of the friction is 8.94 Wh / km in JC08 mode.

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Steering shimmy is a phenomenon of straight-driving performance that causes customer dissatisfaction. This paper describes the Steering shimmy improvement utilizing the Quality Variation Control Process which is developed by Nissan to improve quality variation. Design countermeasures and key characteristics to be controlled in the manufacturing process are clarified by conducting the design response analysis and the variation effect analysis. Appling the countermeasures to a new model in US market the Steering shimmy nominal value and variation improvement is confirmed.

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Common automobile trims are made of polypropylene with grained or wooden texture. Although people regard a trim as comfortable due to its high-grade appearance, once they knock it, they feel uncomfortable because the knocking sound is very cheap in contrast to its appearance. This is because the trim development is based on only visual sensation. For this reason, the demand for new-design trims with both high-grade appearance and high sound quality is rising. In this study, following three results are shown: (1) comfortable knocking sound index, (2) structure to make pleasant sounds, (3) effect of both appearance and sound improvement.

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To realize efficient combustion noise countermeasures focused on enhancement of sound quality, a method was constructed that uses multiple regression analysis to separate the contributions of combustion noise and mechanical noise in the time domain. Compared to the conventional method, this new method understands the combustion noise of each cylinder and calculates a structural transfer function that takes into account the phase. This method was used to analyze actual engine radiation noise, and the results confirmed that combustion noise, which is a strong cyclically fluctuating noise, can be accurately separated from other irregular mechanical noise in the time domain. In addition, the structural transfer function and the separated combustion noise and mechanical noise exhibited appropriate characteristic changes with respect to in-cylinder pressure and structural specification changes, which confirmed the validity of this method.

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Current study investigated which cognitive functions were related with occurrence of the backward maneuver and merging behaviour in highway. We found that the cognitive function for re-mapping of the intrinsic - extrinsic coordinate was correlated with driving performance on backward maneuvers, particularly, parking (Experiment 1). We also found that both of the cognitive functions in attention and its switching and in decision-making caused individual differences in merging behaviour at highway ramps (Experiment 2).

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Although the number of senior drivers in Japan has been rising yearly, a specific and proven training method for senior drivers still remains to be developed. To develop such a training method, anti-human error measures should be studied from a comprehensive viewpoint based on an analysis of (1)recurrent traffic accident, (2)the driver's aptitude, and (3)the senior driver's actual driving behavior. In this study, we consider an approach to grasp actual situation of the senior driver's driving behavior and confirming safe conditions as a preparation for the development of this training method.

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In this paper, thoracic and abdominal injury of motor vehicle belted occupant’s in frontal impact was analyzed based on in-depth accident sampling and investigation with medical and engineering network data. A total of 28 patients with AIS 2＋ injury data was collected. We analyzed the relationships between frequency distribution of chest and abdominal injury and injury source, vehicle equivalent barrier speed(EBS), age effect. The results show that rib/sternum injury, lung injury and mesentery injury were occurred frequently belted occupant’s in frontal impact. It found that chest injury were occurred at EBS 25 km/h, abdominal injury was occurred at EBS 35 km/h.

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The effect of sun glare direction on traffic accident occurrence in Chiba was analyzed. It was found that the rate of rear-end accidents tended to be higher when the sun was behind the vehicle. The rate of right- and left-turning accidents tended to be higher when the sun was in front of the vehicle. The rate of left-turning accidents tended to be higher when the sun was in front or on the left. Accidents between right-/left-turning cars and oncoming cyclists/pedestrians tended to be migh higher when the sun was in front of the vehicle. Vehicle drivers were adversely affected by sun glare not only from the front but also from other directions.

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The conspicuity of the motorcycles put on the market in recent years is evaluated paying attention to the closing collision, right turn collision and the rear-end collision. First report has shown that the relative arrangement of headlights and position lights affects motorcycle conspicuity. In the second report, more detailed analysis of the arrangement of position lights is conducted, and also analysis of the arrangement of headlights and stop lamps is conducted. The relative arrangement of headlights and position lights and the light intensity of headlights in front of the vehicle affect motorcycle conspicuity of the front. The height of stop lamps affects motorcycle conspicuity of the back.

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This research investigated how to present a critical and urgent message among different messages through visual and auditory displays at the same time to reduce negative impacts on drivers’ responses to dangerous situations. Participant drivers were provided from one to four different messages through visual and auditory displays while driving on a straight road and stopping at the intersection in the driving simulator. The results indicated that drivers found it difficult to understand messages when many displays were presented simultaneously. The results also demonstrated that presenting many messages negatively impacted drivers’ reactions to risky situations and controlling their vehicle before entering a curve. However, when the most important message was differentiated from other ones by color and size of visual presentations and by tone of auditory presentations, the negative impacts were reduced even when many displays were presented, especially for the curve situation.

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The comfortable environment in a truck cabin is important for a truck driver. Thus the purpose of this study is to discuss ventilation efficiencies and inhaled air quality in a truck cabin with human body model, which has not been considered in the previous research. In this research, at first, the flow behavior of a 1/3 scaled truck model is evaluated and the accuracy of CFD results is discussed by the comparison with experimental results. Then, the Ventilation Efficiencies and inhaled air quality are evaluated by CFD and the impact from human body upward flow is discussed.

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These measures that are reduction of global warming gasses, saving energy and fuel diversification need a method of considering cost effectiveness in the long-term. Especially, China, India and ASEAN countries are predicted to rapidly increase demand in the transport sector. The authors focused on passenger car sectors in these three regions and developed an energy and CO₂ emission analysis model that is based on the multinomial logit model that projects probability of consumer’s choices. The authors estimated CO₂ reduction potential by assuming not only future automotive technology evolutions but integrated approaches such as eco-driving and improved traffic flows by the year 2050. As results, total CO₂ emission in three regions with technology advanced and integrated approach case is estimated to be decreased by 45% compared with a business as usual case defined in this paper.

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The fatigue strength of bolt and nut is experimentally investigated for three types of different pitch difference. The effect of fitting clearance on the strength of bolt is discussed as well as the effect of pitch difference. The conclusions are summarized as follow : (1)By introducing the pitch difference, the mean stress and stress amplitude can be reduced at the first root of bolt thread. (2)The fracture position of bolt thread is changed depending on the pitch difference. (3)The clearance affects the stress distribution along threads more significantly when the pitch difference is larger.

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The influence of residual stresses on the fatigue strength of specimens with a punched hole was investigated in two grade high strength steel sheets. Punching induces tensile and compressive residual stresses in the circumferential direction near the edge of the hole. Tensile residual stress exists in the area of shear drop and the area of fractured surface. Proper conditions of stress relief heat treatment were selected to avoid softening around the hole. The increase of fatigue strength by the heat treatment should depend on the decrease of tensile residual stresses near the edge of the hole.

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The panel stiffness of door parts has been evaluated sensuously by hand-pushing. In this study, it is succeeded to evaluate and to predict the panel stiffness quantitatively by optimizing the indenter condition. Especially, it is the most important that the indenter size is adjusted to the examiner’s palm. By applying the indenter condition, the experimental results are reproduced in the finite element analysis. Accordingly, door parts could be designed more easily in consideration of panel stiffness without the trial manufacturing. Finally, it is expected that weight saving examination could be possible in the early stages of automotive development.

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