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The effect of ambient gas hydrocarbon content on diesel spray ignition and combustion was examined in this research project. A single-stroke rapid compression machine was used to prepare the ambient gas pressure and temperature before the diesel fuel injection process. Variations of ambient gas composition were achieved by adding different quantities of methane and propane to the intake air, the content ranged from 0.0 to 0.6 equivalence ratio. The two-color method was applied to analyze the flame temperature and KL factor was determined from the colored flame image taken by a high-speed camera. Also, compression ignition characteristics of lean methane-air and propane-air mixtures were examined.

Typical DI diesel engines operate with fuel injection taking place within a range of about 30 crank angle degrees before top dead center, at the end of the compression stroke. When injection takes place far earlier, at the beginning of the compression stroke, another form of combustion occurs, which we termed PREmixed lean Diesel Combustion, or PREDIC. With PREDIC operation, self-ignition occurs near top dead center and NOx emissions are drastically lower. When ignition occurs, the fuel-air mixture is thought to be nearly homogeneous, with only slight heterogeneity. Appropriate fuel spray formation is very important for successful PREDIC operation. Using a single-zone NOx formation model, calculations showed that the mean excess air ratio in the PREDIC combustion zone was 1.87, which resulted in very low (20 ppm) NOx emissions. Conventional combustion at the same conditions resulted in a mean combustion zone excess air ratio of 0.88.

For some years now the new HID technology has been used for headlamp systems to improve safety and comfort during night time driving. A new generation of projector type headlamps starts series production in 1997. The characteristics of the HID bulb and the specific requirements of the light distribution make it necessary to calculate special optical systems to control the high amount of light. There are different possible design strategies. On one hand, it is possible to improve the light pattern, e.g. increase the luminous flux and the range. On the other hand it is possible to build a system with extremely small dimensions. Such a system ensures an excellent light quality even in smallest headlamps and gives way to new styling possibilities. To match such different targets, some parameters of the reflector and the lens have to be optimized. Some examples of projection headlamps which are designed for different applications will be discussed.

Signal lamp for a motor vehicle with a complex reflector design is presented. The reflector is composed of set of rectangular bicubic Bezier ‘pillows’ creating desired horizontal and/or vertical light spread. Cover lens with no or weakly-spreading optics is assumed. Mathematical background is discussed in part 2 - parametric equations for individual pillow are presented, equations for control points ensuring proper optical function of the pillow are derived and parameter controlling intensity distribution of output beam is introduced. Option to prevent beam asymmetry of conventional signal lamps with big rake angles of cover lens using ‘semicomplex’ optical system (i.e. complex reflector combined with optical elements on the cover lens) is discussed, too.

A design strategy for implementing High Intensity Discharge (HID) light sources in low beam head lamps with Free-Form Reflectors (FFRs) is presented. A theoretical analysis of a light source image formed by each portion of a reflector is presented as well as a strategy for using those images to create a head lamp beam pattern. Simulation results are shown for a head lamp design using this strategy.

For the automotive industry, the styling of a car is an important feature. Since the appearance of a car is strongly characterized by the headlamp, stylistic aspects have an increasing influence on the development of headlamps. At the same time, the trend goes toward reducing the constructional volume available to the headlamp and also integrating other functions such as foglamps. To fulfill all these requirements, new reflector shapes had to be created. In this paper, different reflector concepts for low beam, high beam and foglamps are presented. They will be discussed under consideration of stylistic aspects (e.g. space for the required bulb shield, semi-clear outer lens) and technical aspects (e.g. thermal stress of plastic lenses).

In recent years, the automotive industry has seen a rapid increase in the “on-board electronics content” of vehicles. Such technology has given rise to ever increasing levels of safety, comfort and performance in this high production-volume industry. Cost considerations require that most on-board electronics be implemented on fixed-point processors. As companies look to extract more (performance) for less (implementation costs & lead time) the job of designing on-board fixed-point application software is becoming more and more challenging. This paper discusses the use of fixed-point design tools that were recently introduced in the MATRIXx® product family. These tools feature a high-performance fixed-point simulator, and a kit of interactive tools that enable engineers to study signal ranges and overflow/underflow conditions. Tools to perform trade-off studies between performance and fixed-point attributes are also discussed.

Automotive applications require complex systems with strong interaction between electrical and mechanical modes of operation. To achieve fast to market products and reduce development costs, math modeling is essential to analyze these complex mechatronic systems and accurately characterize their behavior. One of the tools widely employed by GM to address this need is Sabera®. While Sabera® is well developed in electrical and mechanical domains, it is difficult to accurately model the magnetic behavior. To alleviate this problem, the magnetic circuit is characterized by the finite element analysis program, Maxwell®, and then integrated with Saber®. This paper discusses the development of models using this process with a transmission application.

The development of modern engine mechanical systems and electronic control systems has been advanced significantly over the last few years by increased use of engine modeling. A key requirement for improved modeling will be more accurate verification of the prototype engine performance to that predicted by the model. As percentage gains in engine power, fuel economy, and emissions become incrementally smaller, accurate measurements of these parameters are more critical. In addition, as engine testing in the dyno cell moves more toward transient operating conditions which more accurately represent actual driving conditions, measurement speed of the engine and ECM performance must increase tenfold or more to fully characterize transient behavior. This paper will illustrate these points with examples of engine development problems accompanied by descriptions of the key data system requirements such as sampling speed, measurement accuracy, and triggering flexibility.

PET (Powertrain Engineering Tool) [1, 2] is based on an object-oriented hierarchy system and therefore each component (parent) has its own sub-component (child) systems. Developing explicit forms of objective functions and constraints is simple due to the object-oriented component system of PET. This system automatically recognizes the geometry of components and related design functions in its sub-component levels. This paper discusses computational efficiency, solution accuracy and robustness of software when using closed-form representatives of the derivatives of objective functions and constraints in sequential quadratic programming. Examples of generating closed-form representatives of the derivatives of objective functions and constraints in C/FORTRAN language syntax by using a symbolic processor, Mathematica [3], and mass reduction of the piston-pin are also presented.

A numerical process, which consists of free or force vortex motion, boundary element methods and optimization methods, was developed to calculate the design parameters of an axial flow fan. Rotational speed, tip and hub diameters, and number of blade were used as the input data. Stagger angle, radial varation of the blade angles, was calculated with this numerical process. Sum of the difference of the stagger angle for numerical solution and that for current design was minimized by using the optimization methods. Parameters of the computational solution, including lift and drag of an aerofoil, inlet flow angle and velocity, outlet flow angle and velocity, and variation of axiaI velocity in the radial direction, were calculated to investigate the current product of axial flow fan. Three cases were run to validate the numerical solutions. Case A and case B were the Valeo's current products; case C was the Valeo's prototype fan.

Hardware-in-the-Loop Simulation allows ECUs to be tested in a simulated environment in closed loop. Engines, vehicles, and other components the ECU normally controls are replaced by high-fidelity models executed on a real-time computer system. This paper shows that today's hardware/software technology makes comprehensive and powerful low-cost desktop simulators feasible. It is also shown that it is now possible to use the same tools for Hardware-in-the-Loop Simulation that have been used in the control development.

In today's automotive development environment it is necessary to look at the totality of an automotive system. For this approach is necessary in order to optimize system designs for reliability, manufacturability and cost. Optimization in the case of the automotive system or subsystems, entails performing trade-off studies on the different components taking into account their interactions. In doing so it is necessary to employ a mixed domain simulation tool. In the case of the Cranking and Charging System electrical, mechanical and thermal domains must be co-simulated. The focus of this paper will be to show how a typical Cranking/Charging system can be analyzed and how the appropriate design decisions can be made.

Simulation is by now considered an essential activity prior to the implementation of complex, embedded real-time systems such as automotive control units. However, the models required for a meaningful systems simulation are often heterogeneous -(such as software, hardware, hydraulics, mechanics etc.) and developed in parallel using different tools from different vendors, thereby making comprehensive system simulations very hard. An open architecture for cosimulation of heterogeneous systems and its first implementation within the MATRIXx tool family, based on the Common Object Request Broker Architecture (CORBA) is described. It allows plug-and-play cosimulations between a wide range of simulation tools and can serve as the foundation of sophisticated virtual prototyping and systems simulation activities.

KIA has completed the development of the future DOHC 16 valve spark ignition engine designated the T-series. An all new design was devised for the T-series engine which is being produced on an entirely new plant. This engine has many positive features such as low emission level, good combustion stability, low noise and vibration. The basic construction of the T-series engine is characterized by 4 cylinder belt-driven DOHC engine, state-of-the-art combustion chambers with tumbling intake ports and a valve angle of 45, deep skirt cylinder block, laminated metal cylinder head gasket, aluminum structural oil pan, and a six ribbed serpentine belt driven accessory system. Thorough durability testing was carried out on all production parts for the first engine of the T-series; called the T8D engine, of 1.8 litre displacement. Mass production of the T8D engine, installed in the new KIA CREDOS, began in July 1995.

For a 1997 model year passenger car, Honda has released an all-new 3.0 liter, transversely mounted, SOHC VTEC (Variable Valve Timing and Lift Electronic Control) V6 engine. This compact, light-weight, state-of-the-art V6 engine achieves 147 kW @ 5500 rpm, improves fuel economy, and uses regular unleaded fuel. This is the world's first SOHC VTEC V6 engine, and the first V6 to be manufactured in the United States by Honda.

Modern passenger car engines are designed to operate at increasingly higher rated engine speeds with more internal parts (multi-valve engines) requiring lubrication. The paper presents results of research and development activities to reduce the actual feed rate of the oil consumers to their real requirements depending on the most significant influence parameters. Based on these results an optimization strategy is presented which combines CAE tools with data from experimental work. In the conclusion of the paper recommendations are summarized to show the optimization potential of actual lubrication and ventilation systems concerning design. power input respectively oil consumption.

Ford introduced a new in-line 4-cylinder 2.3L DOHC 16-valve engine in its European D-class Scorpio vehicle. The engine is based on the proven 2.0L-DOHC engine with 8 or 16 valves. The new engine replaces the 2.0L DOHC 8-valve version. Primary focus of the development of this new 2.3L engine was on the noise and vibration improvement, both for the engine and for the vehicle interior noise. One measure to achieve this target was the application of balance shafts. In this paper, the development of the new engine will be described from the design stage to the production version. It will focus on the design of the balance shaft housing and all relevant engine NVH features. The various stages of the design and detailed optimization are explained. The NVH prediction by CAE methods is verified with experimental results. The influence of optimized components like the oil pan, front cover and the chain tensioner on the noise behavior will be discussed.

Casting technology developmentshave led to a manufacturing process that allows the casting of thin wall (2-3mm) heat resistant ferritic stainless steel exhaust manifolds which can replace stamped and tubular weldments as well as iron castings where temperature requirements are increased. This casting process combines the thin wall and clean metal benefits of the counter gravity, vacuum-assist casting process using thin, light-weight bonded sand molds supported by vacuum-ridgidized sand. This combination is called the LSVAC (Loose Sand Vacuum Assisted Casting) process, a patented process. This process will significantly contribute to the growth of near-net shape steellstainless steel castings for automotive and allied industries. For exhaust manifolds, a modified grade of ferritic stainless steel with good oxidation resistance to 950°C in high dew point synthetic exhaust gas atmospheres was developed.

Gas shielded metal arc welding is generally applied to automobile chassis parts. However, the weld parts with the E-coat show poor corrosion resistance. Therefore, the corrosion mechanism of the weld parts was investigated. The results found two reasons why the weld parts corroded faster than the non weld parts:(1)inadequate phosphating (2)defects in the E-coat. After detailed investigation, it was clarified that the major cause of poor corrosion resistance was the defects in the E-coat caused by slags formed on the surface of the weld bead. Therefore the amount of slag has to be decreased to improve the corrosion resistance. The effect of shielding gas composition on the amount of slag was then investigated. In the case of Ar and oxidizing gas mixture, the corrosion resistance improved as the oxidizing gas content decreased. This was due to the reduction of slags.