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Economic market forces and increasing environmental awareness of gasoline have led to interest in developing alternatives to gasoline, and extending the current global supply for transportation fuels. One viable strategy is the use of alternative alcohol fuels for combustion engines, with ethanol and methanol in various concentration ranges proposed and in-use. Utilizing and citing data from this review, a comprehensive overview of the materials selection and engineering challenges facing metals, plastics and elastomers are presented. The engineering approach and solution-sets discussed will focus on production feasibility and implementation. The effects from the fuel chemistry and quality of fuel ethanol produced on the related vehicle components are discussed.

Currently, the dominant technology used in the manufacture of mass-market automobile structures is sheet-metal stamping because of its suitability for producing accurate, strong, durable components in large quantities [1]. While cost-effective and fast for high-volume applications, the cost of manufacturing stamping dies is difficult to profitably amortize over a low-volume product in any but the most high-priced vehicle segments. This study examines the application of automated fabrication technologies as an alternative to stamping for the production of low-volume body structure components, including the impacts on both design and performance.

Internal combustion engines (ICEs) exhaust emissions, particularly nitrogen oxides (NOx), have become a growing environmental and health concern. The biggest challenge for contemporary ICE industry is the development of clean ICEs, and the use of advanced design tools like Computational Fluid Dynamics (CFD) simulation is paramount to achieve this goal. In particular, the development of aftertreatment systems like Selective Catalyst Reduction (SCR) is a key step to reduce NOx emissions, and accurate and efficient CFD models are essential for its design and optimization. In this work, we propose a novel 3D-CFD methodology, which uses a Machine Learning (ML) approach as a surrogate model for the SCR catalyst chemistry, which aims to enhance accuracy of the simulations with a moderate computational cost. The ML approach is trained on a dataset generated from a set of 1D-CFD simulations of a single channel of an SCR catalyst.

The cooled EGR system has been focused on as a method for knocking suppression in gasoline engines. In this paper, the effect of cooled EGR on knocking suppression that leads to lower fuel consumption is investigated in a turbo-charged gasoline engine. First, the cooled EGR effect is estimated by combustion simulation with a knock prediction model. It shows that the ignition timing at the knocking limit can be advanced by about 1 [deg. CA] per 1% of EGR ratio, combustion phasing (50% heat release timing) at the knocking limit can be advanced by about 0.5 [deg. CA] per 1% of EGR ratio, and the fuel consumption amount can be decreased by about 0.4% per 1% of EGR ratio. Second, the effect of cooled EGR is verified in an experimental approach. By adding inert gas (N2/CO2) as simulated EGR gas upstream of the intake pipe, the effect of EGR is investigated when EGR gas and fresh air are mixed homogeneously. As a result, the ignition timing at the knocking limit is advanced by 7 [deg.

A pioneering approach to implement transfer path analysis (TPA) is proposed in this paper through applying it to an automobile. We propose to use particle velocity as a measure of TPA, in addition to using sound pressure as a conventional measure for TPA. These two quantities together will give a comprehensive and complete definition of sound. Although sound pressure is a scalar, while particle velocity is a vector, it is also proposed that the same technique of the conventional sound pressure TPA should be independently applicable to each component of particle velocity vector. This has been experimentally verified with a study on our test box system. In this paper, we apply the proposed TPA to an actual vehicle to examine its applicability, advantages and limitations. The driving motor sound of a hybrid electric vehicle is chosen as the case study. A tri-axial particle velocity sensor which also measures sound pressure at the same point is utilized in the experiment.

Emission regulations continue to be strengthened, and it is important to decrease cold start hydrocarbon concentrations in order to meet them, now and in the future. The HC concentration in engine exhaust gas is reduced by controlling the air-fuel ratio to the low HC range and retarding the ignition timing as much as possible until the engine stability reaches a certain deterioration level. Conventionally however, the target air-fuel ratio has been set at a richer range than the low HC range and the target ignition timing has been more advanced than the engine stability limit, in order to stabilize the engine for various disturbances. As a result, the HC concentration has not been minimized. To solve this problem, a new engine control has been developed. This control uses a crank angle sensor to simultaneously control the air-fuel ratio and the ignition timing so that the HC concentration can be minimized.

To detect an air-fuel ratio in wide range is very important to control the automotive engines with low fuel consumption and low exhaust emissions. Although the application of zirconia electrolyte for this purpose has been proposed by the authors several years ago, there remained several problems due to the contamination of gas diffusion apertures which are exposed to the exhaust gas environment. Here the behavior of ions transported in zirconia electrolyte have been analyzed to optimize the structure and characteristics, and to guarantee the long life operation of sensor. Gas contents and their reactions in combustion process under the wide range air-fuel ratio have been analyzed, and these results were reflected to the analysis of ion transportation in zirconia electrolyte. Experimental results supported the analytical results, and they showed the possibilities of long life operation of zirconia air-fuel ratio sensor utilizing ion transportation phenomena.

A new urea-dosing device with an active-ammonia production function was developed. This function is achieved by an electrically heated bypass passage with a hydrolysis catalyst for urea-to-ammonia conversion. The new device also has the function of mixing ammonia and exhaust gas. It is compact and has low-pressure loss by using the vortex occurring at the back of a static vane. We built a trial device for a small diesel engine and obtained steady state and transient data. The heated-bypass concept can be used in the aftertreatment system of passenger cars. Although active-ammonia production consumes electric power, a predictive calculation of power consumption (based on experimental results) shows that the developed bypass heater can suppress the energy consumption enough not to harm the high-energy efficiency of diesel engines.

The present work aims to characterize the microstructure of valvetrain camshaft lobes that are currently applied in the automotive industry, obtained by different processing routes. The cam lobe microstructure has been assessed by microscopy, whereas the mechanical properties by hardness profile measurements on the surface region. Microconstituents type and form, composing the final microstructure at the cam lobe work region, are defined by the casting route and/or post-heat treatment process other than alloy chemical composition, so that knowledge and control of processing route is vital to assure suitable valvetrain system assembly performance and durability. Most of the mechanical solicitations on the part occur at the interface between cam and follower; the actual contact area is significantly smaller than the apparent area. As a result, the microstructure at and near the surface performs a direct role on the performance of the valvetrain, cam lobe and its counterpart.

Deionized (DI) water is being used for humidification and cooling on some fuel cell designs. This highly purified water is corrosive, yet the high purity is required to maintain the function and durability of the fuel cell. A study of the deionized water system was undertaken to determine the effect of various materials on water quality, and also to determine the effect of deionized water on each material. The test setup was designed to circulate fluid from a reservoir, similar to an actual application. The fluid temperature, pressure, and flow rate were controlled. The resistivity of the water was observed and recorded. Pre- and post-testing of the water and the materials was performed. The goal is to achieve system cleanliness and durability similar to a stainless steel system using lighter, less expensive materials. This paper describes the test setup, test procedures, and the overall results for the eight materials tested.

A continuously variable valve event and lift (VEL) system, actuated by oscillating cams, can provide optimum lift and event angles matching the engine operating conditions, thereby improving fuel economy, exhaust emission performance and power output. The VEL system allows small lift and event angles even in the engine operating region where the required intake air volume is small and the influence of valvetrain friction is substantial, such as during idling. Therefore, the system can reduce friction to lower levels than conventional valvetrains, which works to improve fuel economy. On the other hand, a distinct feature of oscillating cams is that their sliding velocity is zero at the time of peak lift, which differs from the behavior of conventional rotating cams. For that reason, it is assumed that the friction and lubrication characteristics of oscillating cams may differ from those of conventional cams.

Highly automated driving systems have a responsibility to keep a vehicle safe even in abnormal conditions such as random or systematic failures. However, creating redundancy in a system to respond to failures increases the cost of the system, and simple redundancy cannot detect systematic failures because some systematic failures occur in each system at the same time. Systematic failures in automated driving systems cannot be verified sufficiently during the development phase due to numerous patterns of parameters input from outside the system. A safety concept based on a “safety sustainer” for highly automated driving systems is proposed. The safety sustainer is designed for keeping a vehicle in a safe state for several seconds if a failure occurs in the system and notifying the driver that the system is in failure mode and requesting the driver to take over control of the vehicle.

In this work, an experimental and analysis methodology was developed to evaluate the preignition propensity of fuels and engine operating conditions in an SI engine. A heated glow plug was introduced into the combustion chamber to induce early propagating flames. As the temperature of the glowplug varied, both the fraction of cycles experiencing these early flames and the phasing of this combustion in the engine cycle varied. A statistical methodology for assigning a single-value to this complex behavior was developed and found to have very good repeatability. The effects of engine operating conditions and fuels were evaluated using this methodology. While this study is not directly studying the so-called stochastic preignition or low-speed preignition problem, it studies one aspect of that problem in a very controlled manner.

As automotive OEMs (Original Equipment Manufacturer) struggle to reach a balance between Design and Performance, environmental legislations continues to demand more rapid gains in vehicle efficiency. As a result, more attention is being given to the contributions of both tire and wheels. Not only tire rolling resistance, but also tire and wheel aerodynamics are being shown to be contributors to overall efficiency. To date, many studies have been done to correlate CFD simulations of rotating wheels both in open and closed wheeled environments to windtunnel results. Whereas this ensures proper predictive capabilities, little focus has been given to thoroughly explaining the physics that govern this complex environment. This study seeks to exhaustively investigate the complex interactions between the ground, body, and a rotating tire/wheel.

A new engine drivetrain control system is described which can provide a higher gear ratio and leaner burning mixture and thus reduce the fuel consumption of spark ignition engines. Simulations were performed to obtain reduced torque fluctuation during changes in the air - fuel ratio and gear ratio, without increasing nitrogen oxide emissions, and with minimum throttle valve control. The results show that the new system does not require the frequent actuation of throttle valves because it uses direct fuel injection, which increases the air - fuel ratio of the lean burning limit. It also achieves a faster response in controlling the air mass in the cylinders. This results in the minimum excursion in the air - fuel ratio which in turn, reduces nitrogen oxide emissions.

A new diagnosis method for an air-fuel ratio cylinder imbalance has been developed. The developed diagnosis method is composed of two parts. The first part detects an occurrence of an air-fuel ratio cylinder imbalance by using a two revolution frequency component of an EGO sensor output signal or an UEGO sensor output signal upstream from a catalyst. The two revolution frequency component is from a cycle where an engine rotates twice. The second part of the diagnosis method detects an increase of emissions by using a low frequency component which is calculated from the output of an EGO sensor downstream from the catalyst. When the two revolution frequency component calculated using the upstream sensor output is larger than a certain level and the low frequency component calculated using the downstream sensor output is shifted to a leaner range, the diagnosis judges that the emissions increase is due to an air-fuel ratio cylinder imbalance.

The need for accurate virtual prototyping prediction is well documented in the literature. For welded body structures one notable shortcoming has been the ability for finite element analysis (FEA) to accurately predict the failure of welded joints due to cyclic loading. A new approach to representing spot-welds for durability evaluation in automotive sheet metal structures is presented here. Excellent correlation with spot-weld failures in actual tests have been observed through this modeling approach. We present a method of representing spot-welds using the finite element method. This method has shown to be able of predicting the behavior of spot-welds prior to the build of any prototypes or testing. Further, for spot-weld failures we present evidence that reveals which radial quadrant of the spot-weld will contain the failure. This method also allows engineers to determine the mechanism of failure. This paper describes in detail the spot-weld modeling method.

Model-based methodologies for the engine calibration process, employing engine cycle simulation and polynomial regression analysis, have been developed and the reliability of the proposed method was confirmed by validating the model predictions with dynamometer test data. From the results, it was clear that the predictions by the engine cycle simulation with a knock model, which considers the two-stage hydrocarbon ignition characteristics of gasoline, were in good agreement with the dynamometer test data if the model tuning parameters were strictly adjusted. Physical model tuning and validation were done, followed by the creation of a dataset for the regression analysis of charging efficiency, EGR mass, and MBT using a 4th order polynomial equation. The stepwise method was demonstrated to yield a logarithm likelihood ratio and its false probability at each term in the polynomial equation.

Low pressure cooled exhaust gas recirculation (EGR) to suppress engine knocking is increasingly being used to downsize engines and increase the compression ratio to improve thermal efficiency. This study aims to develop an ignition system to extend the EGR limit and EGR operation area. The ignition system must be improved to enhance ignitability of a mixture of fuel and air. In this paper, we focus on ignition energy of the ignition coil and summarize experimental results on a test dyno obtained by using reinforced conventional ignition coil on the basis of ignition energy and engine speed. As engine speed (mixture flow velocity between ignition plug electrode-gap) and EGR ratio were increased, the secondary energy requirement of the ignition coil was increased. This increase was considered to be caused by an increase of mixture flow velocity at the plug gap and a decrease of laminar flame velocity as EGR ratio increased.

A hydrogen economy is an increasingly popular solution to lower global carbon dioxide emissions. Previous research has been focused on the economic conditions necessary for hydrogen to be cost competitive, which tends to neglect the effectiveness of greenhouse gas mitigation for the very solutions proposed. The holistic carbon footprint assessment of hydrogen production, distribution, and utilization methods, otherwise known as “well-to-wheels” carbon intensity, is critical to ensure the new hydrogen strategies proposed are effective in reducing global carbon emissions. When looking at these total carbon intensities, however, there is no single clear consensus regarding the pathway forward. When comparing the two fundamental technologies of steam methane reforming and electrolysis, there are different scenarios where either technology has a “greener” outcome.