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A new ring pack model has been developed based on the curved beam finite element method. This paper describes the first part of this model: simulating gas pressure in different regions above piston skirt and ring dynamic behavior of two compression rings and a twin-land oil control ring. The model allows separate grid divisions to resolve ring structure dynamics, local force/pressure generation, and gas pressure distribution. Doing so enables the model to capture both global and local processes at their proper length scales. The effects of bore distortion, piston secondary motion, and groove distortion are considered. Gas flows, gas pressure distribution in the ring pack, and ring structural dynamics are coupled with ring-groove and ring-liner interactions, and an implicit scheme is employed to ensure numerical stability. The model is applied to a passenger car engine to demonstrate its ability to predict global and local effects on ring dynamics and oil transport.

A new multiple dc-inputs direct electric-power converter (D-EPC) has been developed. It is placed between multiple dc power sources and an ac motor, eliminating the need for a dc/dc converter generally used in conventional converter/inverter systems. The D-PEC can improve the efficiency of the motor drive system with a more compact size. Its power distribution control is carried out by allotting voltage ratios to each of two different dc power sources on a time average basis. A new pulse-width-modulation (PWM) generation technique to drive switching devices in the D-EPC has also been developed. Tests have verified that the three-phase ac motor can be operated by controlling the power distribution between the two power sources.

Rare earths are a group of elements whose availability has been of concern due to monopolistic supply conditions and environmentally unsustainable mining practices. To evaluate the risks of rare earths availability to automakers, a first step is to determine raw material content and value in vehicles. This task is challenging because rare earth elements are used in small quantities, in a large number of components, and by suppliers far upstream in the supply chain. For this work, data on rare earth content reported by vehicle parts suppliers was assessed to estimate the rare earth usage of a typical conventional gasoline engine midsize sedan and a full hybrid sedan. Parts were selected from a large set of reported parts to build a hypothetical typical mid-size sedan. Estimates of rare earth content for vehicles with alternative powertrain and battery technologies were made based on the available parts' data.

In today's highly competitive automotive markets manufacturers must provide high quality products to survive. Manufacturers can achieve higher levels of quality by changing or improving their manufacturing process and/or by product inspection where many strategies with different cost implications are often available. Cost of Quality (CoQ) reconciles the competing objectives of quality maximization and cost minimization and serves as a useful framework for comparing available manufacturing process and inspection alternatives. In this paper, an analytic CoQ framework is discussed and some key findings are demonstrated using a set of basic inspection strategy scenarios. A case of a welded automotive assembly is chosen to explore the CoQ tradeoffs in inspection strategy selection and the value of welding process improvement. In the assembly process, many individual components are welded in series and each weld is inspected for quality.

For better understanding of soot formation and oxidation processes in a diesel spray flame, two kinds of planar soot imaging techniques, Laser-Induced Incandescence (LII) and Laser Scattering (LS) techniques, were applied simultaneously to a diesel spray flame in a constant-volume combustion vessel under a diesel-like condition (2.5MPa, 940K). An analysis of LII and LS images yielded 2-dimensional distribution images of concentration, size and number density of soot particles in the spray flame, based on an assumption that LII and LS signals are proportional to the soot particle size to the power of 3 and 6, respectively. In order to obtain clearer variation trend in the soot concentration, size and number density distribution in significantly fluctuating single-shot diesel spray flames, spontaneous and time-integrated ensemble averaging of the laser-measured images were employed.

Detergent additives in automotive gasoline fuel are mainly designed to reduce deposit formation on intake valves and fuel injectors, but it has been reported that some additives may contribute to CCD formation. Therefore, a standardized bench engine test method for CCDs needs to be developed in response to industry demands. Cooperative research between the Petroleum Association of Japan (PAJ) and the Japan Automobile Manufacturers Association, Inc. (JAMA), has led to the development of a 2.2L Honda engine dynamometer-based CCD test procedure to evaluate CCDs from fuel additives. Ten automobile manufacturers, nine petroleum companies and the Petroleum Energy Center joined the project, which underwent PAJ-JAMA round robin testing. This paper describes the CCD test development activities, which include the selection of an engine and the determination of the optimum test conditions and other test criteria.

Achieving a multi-cylinder engine with excellent noise/vibration character sties and low friction at the main bearings requires an optimal design not only for the crankshaft construction but also for the bearing support system of the cylinder block. To accomplish that, it is necessary to understand crankshaft system behavior and the bearing load distribution for each of the main bearings. Crankshaft system behavior has traditionally been evaluated experimentally because of the difficulty in performing calculations to predict resonance behavior over the entire engine speed range. A coupled crankshaft-block analysis method has been developed to calculate crankshaft system behavior by treating vibration and lubrication in a systematic manner. This method has the feature that the coupled behavior of the crankshaft and the cylinder block is analyzed by means of main bearing lubrication calculations. This paper presents the results obtained with this method.

The spray formation and mixing processes in a direct-injection gasoline engine are examined by using a sophisticated air flow calculation model and an original spray model. The spray model for a spiral injector can evaluate the droplet size and spatial distribution under a wide range of parameters such as the initial cone angle, back pressure and injection pressure. This model also includes the droplet breakup process due to wall impingement. The arbitrary constants used in the spray model are derived theoretically without using any experimental data. Fuel vapor distributions just before ignition and combustion processes are analyzed for both homogeneous and stratified charge conditions.

This paper describes a low-cost 48 × 48 element thermal imaging camera intended for use in measuring the temperature in a car interior for advanced air conditioning systems. The compact camera measures 46 × 46 × 60 mm. It operates under a program stored in the central processing unit and can measure the interior temperature distribution with an accuracy of ±0.7°C in range from 0 to 40°C. The camera includes a thermoelectric focal plane array (FPA) housed in a low-cost vacuum-sealed package. The FPA is fabricated with the conventional IC manufacturing process and micromachining technology. The chip is 6.5 × 6.5 mm in size and achieves high sensitivity of 4,300 V/W, which is higher than the performance reported for any other thermopile. This high performance has been achieved by optimizing the sensor's thermal isolation structure and a precisely patterned Au-black absorber that attains high infrared absorptivity of more than 90%.

Battery packs for Hybrids, Plug-in Hybrids, and Electric Vehicles are assembled from a system of modules (sheets) with a tight sheet metal casing around them. Each module consists of an array of individual cells which vary in the composition of electrodes and separator from one manufacturer to another. In this paper a general procedure is outlined on the development of a constitutive and computational model of a cylindrical cell. Particular emphasis is placed on correct prediction of initiation and propagation of a tearing fracture of the steel can. The computational model correctly predicts rupture of the steel can which could release aggressive chemicals, fumes, or spread the ignited fire to the neighboring cells. The initiation site of skin fracture depends on many factors such as the ductility of the casing material, constitutive behavior of the system of electrodes, and type of loading.

The influence on vehicle dynamics of braking force distribution to four wheels has been analyzed by computer simulation and experimentation. The analytical results indicate that a suitable braking force distribution control method can improve handling and stability during braking. A new braking force distribution cintrol strategy,using a steering wheel angle feedforward function and a yaw velocity feedback function,is shown to improve vehicle dynamic behavior.

Flow velocity distributions in the passenger compartment were measured from visualized images of particle flow paths obtained with a full-scale model. The flow paths were visualized using an approach that combined a particle tracing method with a pulse-laser light technique. Air was used as the fluid medium with the full-scale passenger compartment model and water was used as the fluid medium with a one-fourth scale model. A comparison of the results obtained with the two models confirmed that there was good agreement between the flow velocity distributions. Using the full-scale model, measurements were also made of the flow velocity distributions when two dummies were placed in the front-seats.

The combustion process after auto-ignition is investigated. Depending on the non-uniformity of the end gas, auto-ignition could initiate a flame, produce pressure waves that excite the engine structure (acoustic knock), or result in detonation (normal or developing). For the “acoustic knock” mode, a knock intensity (KI) is defined as the pressure oscillation amplitude. The KI values over different cycles under a fixed operating condition are observed to have a log-normal distribution. When the operating condition is changed (over different values of λ, EGR, and spark timing), the mean (μ) of log (KI/GIMEP) decreases linearly with the correlation-based ignition delay calculated using the knock-point end gas condition of the mean cycle. The standard deviation σ of log(KI/GIMEP) is approximately a constant, at 0.63. The values of μ and σ thus allow a statistical description of knock from the deterministic calculation of the ignition delay using the mean cycle properties

Hydraulic power steering is applied for petrol and diesel models of Infinity M series to provide supreme feeling of steering. Power assist of hydraulic power steering (here after called HPS), however, does not work when hybrid vehicle is in EV drive mode because the engine, which is the power source stops and the power is not supplied. Electric Power Steering (hereafter called EPS), therefore, “MUST” be installed to assist the power. Here comes the need that Nissan has developed our Hybrid EPS for Infinity M Hybrid model to keep providing supreme feeling of steering of hydraulic power steering without huge packaging change from the standard packaging of petrol & diesel models with hydraulic power steering. Our Hybrid EPS is the 1st hybrid EPS system in the world that is effectuated by oil pressure, and succesively realized by unique and excellent technology of Nissan.

This paper presents a measurement technique to visualize the distribution of the in-cylinder mixture temperature and an experimental approach for analyzing the effect of the temperature distribution prior to ignition on homogeneous charge compression ignition (HCCI) combustion. First, a visualization technique for mixture temperature distribution based on the temperature dependence of laser induced fluorescence (LIF) was developed. As the next step, measurement of the temperature distribution was applied to an analysis of HCCI combustion. Controlled non-uniform temperature distributions in the mixture prior to ignition were generated by a special intake system with a completely divided intake port having separate electrical heaters.

Brake judder caused by uneven heat spots on brake disc surfaces is a major issue in improving vehicle quality. This is especially true for rumble that occurs during high-speed braking. In order to determine the excitation mechanism of brake judder, it is necessary to measure the dynamic brake disc geometry and temperature distribution during actual operation on the road. A noncontact sensor system, suitable for a high temperature environment, was used to monitor these parameters, making it possible to visualize heat spots transiently. The data obtained revealed the influence of pad and disc parameters on heat spot formation.

The use of higher output engines and more auxiliary units is resulting in greater heat generation in the engine compartment. At the same time, design trends and demands for improved aerodynamic performance are diminishing the cooling air flow rate. These two sets of factors are making the thermal environment in the engine compartment more severe. In this work, heat flow in the engine compartment was investigated by numerical analysis and flow visualization, and flow control devices were devised for optimizing the temperature distribution. This paper discusses the heat flow optimization techniques and presents the results obtained in experiments with an actual vehicle.

The thermal environment in the automotive engine compartment is expected to become increasingly severe in the years ahead owing to the installation of a large-size manifold catalyst to reduce exhaust emissions, among other factors. This will make it even more important to analyze the engine compartment layout in terms of heat flow considerations at the design conceptualization stage of a new vehicle. In this research, a flow analysis program called DRAG4D was applied to find the flow velocity distribution and ambient air temperature distribution in the engine compartment during driving, idling and after the engine was turned off. This original program developed at Nissan takes into account the effects of the energy balance and buoyancy, and provides a practical level of prediction accuracy. The time required to create an analytical model and perform the computations has been shortened by using an automatic grid generation function, based on a solid model, and experimental equations.

This paper presents a numerical model of the rotational and lateral dynamics of the piston (secondary motion) and piston slap in mixed lubrication. Piston dynamic behavior, frictional and impact forces are predicted as functions of crank angle. The model considers piston skirt surface waviness, roughness, skirt profile, thermal and mechanical deformations. The model considers partially-flooded skirt and calculates the pressure distributions and friction in the piston skirt region for both hydrodynamic and boundary lubrication. Model predictions are compared with measurements of piston position using gap sensors in a single-cylinder engine and the comparison between theory and measurement shows remarkable agreement.

Japan’s recent dominance of the international auto industry does not result from some major single factor, such as technological superiority or advanced automation. It derives from twenty years of building flexible, durable industrial systems integrating assemblers, suppliers, and related companies. Current competitive advantages result from combinations of seemingly unrelated company, government, and labor practices. Japan’s position of leadership will instigate major changes in international labor forces, corporate strategies, and government policies, as former auto powers adapt to new competition, and simultaneous shifts in energy and economics.