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This study simulates soot formation processes in diesel combustion using a large eddy simulation (LES) model, based on a one-equation subgrid turbulent kinetic energy model. This approach was implemented in the KIVA4 code, and used to model diesel spray combustion within a constant volume chamber. The combustion model uses a direct integration approach with a fast explicit ordinary differential equation (ODE) solver, and is additionally parallelized using OpenMP. The soot mass production within each computation cell was determined using a phenomenological soot formation model developed by Waseda University. This model was combined with the LES code mentioned above, and included the following important steps: particle inception during which acenaphthylene (A2R5) grows irreversibly to form soot; surface growth with driven by reactions with C2H2; surface oxidation by OH radical and O2 attack; and particle coagulation.

Lateral distance from the center of a driver's seating position to the gas and brake pedals is one of the main design factors that relates to the ease of stepping on the pedals from one and the other. It is important to keep a certain distance between the pedals to prevent erroneous operations or to reduce the driver's anxiety. In this paper, we explain that the distance between the pedals is affected by the driver's seating height. In other words, if the driver sits lower, the accuracy of stepping on the pedals from the gas pedal to the brake pedal will increase compared to the higher seating position. In addition, we found out that providing auxiliary parts for the leg support enhances the accuracy of the pedal operations.

We have proposed a human mimetic machine, using electronics control technology, which is quasi-human like an android equipped with volition as a new technical concept for man-machine systems. This machine determines the driver's physiological and psychological conditions and, in response, controls surrounding stimuli, such as sounds and vibrations. In this way, the relationship between the driver and the vehicle is made more human like. To determine the significance of the human mimetic machine, we have been developing a biofeedback vigilance control system, which maintains an optimum vigilance level during driving by controlling stimuli. In the first stage of the study, we have developed an accurate method to determine vigilance level using multiple regression analysis of electroencephalograms.

An Advanced driving simulator has been developed at Mazda Yokohama Research Center. The primary use of this simulator is to research future driver-vehicle systems. In an emergency situation, a driver must respond rapidly to perceived motion and visual stimulus to avoid an accident. In such cases, because the time delay associated with the perception of motion cues is shorter than visual and auditory cues, the driver will strongly rely upon perceived motion to control the vehicle. Hence, a driving simulator to be used in the research of driver-vehicle interactions in emergency driving must include a high performance motion system capable of large amplitude lateral motion. The Mazda simulator produces motion cues in four degrees of freedom, provides visual and auditory cues, and generates control feel on the steering wheel. This paper describes the merit of the large amplitude motion system and the features of this newly developed driving simulator.

A method to inspect the rattle generated in a vehicle cabin has been developed. In the method, the waveform of overall in-cabin noise is analyzed using Wigner distribution, a kind of time-frequency analysis, and the rattle component of the waveform is condensed and separated from the background shake noise. Then the rattle component is classified into three levels, strong, middle and not detected, using a neural network. Fuzzy inference is also used to select normal waveform data. Experimental results show that the correct classification ratio of the method is more than 90%, which equals the ability of skilled inspectors.

This paper describes a calculating method to predict the quasi-static collapsing behaviors of spot-welded closed-hat section curved beams under axial compression. The overall deformat ions and the local buckling modes of beams were calculated using a geometrical model. Force-displacement relations were predicted by a elastic-plastic structural analysis method using the ‘plastic hinge’ concept. Collapsing tests were made on beams which are differenting section size, rotation angle, and metal sheet thickness. Comparisons between the calculated and experimental results of deformed shapes of beams, the local buckling modes and the force displacement relations are discussed.

For a crash analysis using FEM with respect to a structure that is composed of thin plates, we developed a new structure study method (plastic strain equalization method). This method defines the optimality criteria as in the linear analysis of a fully stressed design and indirectly finds an optimal solution. We assume that a structure with both a lightweight and high collapse load should have sufficient strength corresponding to impact loads in each area. This means that at any area the load value and the strength are balanced at a certain value. For the criteria that the plastic strain value is equal over the whole area, a solution can be found by repeating computations. The design variable is the thickness of shell elements and the computation is iterated until plastic strain values are almost equal. In this paper, a structure with both a lightweight and a high collapse load could be optimized by equalizing the plastic strain value.

As a demand for vehicles of higher functionality grows, automakers and material suppliers are devoting increasing efforts to develop technologies for greater safety, lighter weight, higher corrosion resistance, and enhanced quietness. The resin-sandwiched vibration damping steel sheet (VDSS), developed as a highly functional material for reducing vehicle vibration and noise, has been used for oil pans1) and compartment partitions2). First applied for a structural dash panel of the new Mazda 929, a Zn-Ni electroplated VDSS which allows direct electric welding has contributed to greater weight reduction as well as improved quietness.

The thermal fluid field in a vehicle cabin model is analyzed by the mesh free method as well as mentioned in the Part 1. This paper focuses on the steady state indoor climate in the vehicle cabin including the effect of the buoyancy, the heat generation of the driver and heat conduction through the vehicle body surface under the maximum air-cooling condition soaked in a climate chamber in the summer condition for the demonstration of the mesh free method without not only the deformation of the 3D-CAD model but mesh generation. The solar radiation distribution and heat generation through the exhaust pipe from the engine room are simply included in the analysis. Simulated results are compared with experiments in the conditions of both moving and idling states. As a result, no significant difference in air temperature between simulation and experiments can be obtained in both conditions.

A new and very practical technology has been developed to prevent gasoline permeation in plastic fuel tanks. The main body of the new tank is multi-layered, consist of high density polyethylene (HDPE), adhesive resin, polyamide (PA). The top and bottom parts of the tank are single layer consist of HDPE. This method has many advantages including such features as excellent gasoline permeation prevention, the processing time is the same as that for conventional blow molding methods, the method is safe because no toxic substances are used in the treatment process, the cost-performance ratio is excellent due to the minimum use of expensive auxiliaries (PA, adhesive resin), and the top and bottom single layer flashes can be re-used if they are pulverized.

First, this paper describes a measurement of the human back-backrest interface contours and a reduction procedure of the measured contours to reconstruct the statistical back contours of American 50 and 95-percentile male. Second, the paper illustrates the difference of the back contour between the statistical male drivers and SAE 3-D Manikin. Finally, the advantage of using the back contour model in experiment is given. The AM 50 back contour model was used as a loader to obtain the backrest pressure distribution and proved an excellent tool for backrest comfort evaluation.

To coat flexible parts such as R-RIM Urethane Fascia baked at low temperatures, a different painting approach from one for steel parts is employed. Since paint color differences between the fascia and the body would downgrade the product, a color matching technique is required. For better color matching, matching of color shades was attempted with improvement of paint resin, optimal pigment blending and analysis of how color is affected by varying conditions. Application of a primer for finishing has brought about the desired paint film distinctness. Introduced was also the high weatherablilty paint for plastic parts. All such techniques were utilized on R-RIM Urethane Fascia to achieve high-grade color matching.