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This paper explores the extent to which standard dilution tunnel measurements of motor vehicle exhaust particulate matter modify particle number and size. Steady state size distributions made directly at the tailpipe, using an ejector pump, are compared to dilution tunnel measurements for three configurations of transfer hose used to transport exhaust from the vehicle tailpipe to the dilution tunnel. For gasoline vehicles run at a steady 50 - 70 mph, ejector pump and dilution tunnel measurements give consistent results of particle size and number when using an uninsulated stainless steel transfer hose. Both methods show particles in the 10 - 100 nm range at tailpipe concentrations of the order of 104 particles/cm3.

The feasibility of using experimentally determined flow fields at intake valve closing, IVC, as initial conditions for computing the in-cylinder flow dynamics during the compression stroke is demonstrated by means of a computer simulation of the overall approach. A commercial CFD code, STAR-CD, was used for this purpose. The study involved two steps. First, in order to establish a basis for comparison, the in-cylinder flow field throughout the intake and compression strokes, from intake valve opening, IVO, to top dead center, TDC, was computed for a simple engine geometry. Second, experimental initial conditions were simulated by randomly selecting and perturbing a set of velocity vectors from the computed flow field at IVC.

Gas carburized and quenched low alloy steels typically produce surface microstructures which contain martensite, retained austenite and often NMTP's (non-martensitic transformation products). The NMTP's are caused by a reduction of surface hardenability in the carburizing process from loss of alloying elements to oxidation. Gas carburized low alloy steels such as SAE 8620 with NMTP's on the surface have been shown to have inferior bending fatigue properties when compared to more highly alloyed steels which do not form NMTP's, such as SAE 4615M. One method of minimizing the formation of oxides and eliminating NMTP formation during carburizing and quenching is to use plasma carburizing instead of conventional gas carburizing. In this study the microstructures and bending fatigue performance of plasma carburized SAE 8620 and SAE 4615M is compared to the same alloys conventionally gas carburized and quenched.

Spark knock pressure oscillations can be detected by a cylinder pressure transducer or by an accelerometer mounted on the engine block. Accelerometer-based detection is lower cost but is affected by extraneous mechanical vibrations and the frequency response of the engine block and accelerometer. The knock oscillation frequency changes during the expansion stroke because the chamber geometry is changing due to the piston motion and the burned gases are cooling. Spectrogram analysis shows the time-dependent frequency content of the pressure and acceleration signals, revealing characteristic signatures of knock and mechanical vibrations. Illustrative spectrograms are presented which yield physical insight into accelerometer-based knock detection.

A method has been developed for the acquisition and analysis of electrical signals, called combustion signals, from the cylinders of spark ignition engines based on using the spark plugs as ionization probes. A correlation has been established between the simultaneously recorded combustion and cylinder pressure signals based on which combustion signals could be used to identify three types of burns. These burn types were called good burns, slow burns, and misfires. The statistical occurrence of these burn types was also correlated with the hydrocarbon exhaust emission levels for engines operating under dynamometer simulated decelerations and for engines operating with various amounts of exhaust gas recirculation (EGR). Both production and experimental engines have been investigated. It was found that during both decelerations and operation with EGR, the degradation from good burns followed the same pattern irrespective of engine type.

Engine designers need an objective measurement which can be tested on the engine to indicate acceptable idle quality. An experiment was performed to select objective measures based on cylinder pressure data, and two measures were selected. Standard deviation of indicated mean effective pressure (SDimep) is a measure of the statistical instability of combustion. Lowest normalized value (LNV) is a measure of the tendency toward misfire. These two measures are shown for a set of typical engines. The body of data shows the relation of SDimep and LNV to burn duration and timing.

There is a clearly demonstrated need to develop “real-time” methods for the measurement of diesel vehicle particulate emissions. Optical techniques provide One alternative for such methodology because of the rapid data acquisition times involved and the relatively simple sampling methods that can be used. This report describes two different approaches to this problem. The first, the spectrophone, measures light absorption by the diluted exhaust plume using photoacoustic spectroscopy, and the second, the long pathlength smokemeter, determines total light extinction across the diluted exhaust plume. For the measurement of total mass emissions, both techniques show estimated errors of ±15% for specific vehicles, while for a multi-vehicle diesel fleet the estimated errors are ±20% and ±30% for the long pathlength smokemeter and the spectrophone, respectively.

Rapid Prototyping, Fabrication and Tooling is a process that blends a series of technologies (machines, tools, and methods) capable of generating physical objects directly from a CAD database. The process dramatically reduces the time spent during product development by allowing for fast visualization, verification, iteration, optimization, and fabrication of parts and tools. Many new techniques of tooling have been and are being developed by using rapid fabricated parts. These are having a dramatic impact on both timing and costs throughout the automotive industry. One area that these methods can be utilized to their full potential is motorsports. Of particular interest is the growing use of bridge tooling to provide first article through production intent parts that promote cost effective changes.

AMONG the difficulties usually associated with measurement of combustion-chamber volume by liquid methods are amount of time required, contamination of combustion-chamber deposits, and inaccuracies arising from entrapped air. Use of a gaseous fluid such as air as the measuring medium eliminates most of the objectionable features of volume measurement with liquids. Techniques utilizing air for volume measurement fall into two basic classifications: dynamic or sonic methods, and static or pneumatic systems. Cylinder leakage and acoustic damping by engine deposits affect the accuracy of volume measurements based on dynamic properties of combustion-chamber volume, hence small volumes occupied by combustion-chamber carbon deposits must be measured separately by static or pneumatic means.

This research focuses on study of feasibility of using ceramic oxide coatings on the cylinder wall of hypoeutectic aluminum silicon alloy engine blocks. Coatings are achieved in an aqueous electrolytic bath and composed of both alpha and gamma phases of Al2O3 and have shown promising wear resistance. Composition and acidity level of the electrolyte creates a variation of surface roughness, coating hardness and thickness which has direct influence on the wear behavior of the sliding surfaces. The effect of load bearing and coating morphology on coefficient of friction was studied. SEM images of the substrate showed no predominant wear behavior or delamination. Coefficient of friction and wear rate were also measured. This study shows the importance of surface structure on oil retention and wear rate. Coarser coatings can be desirable under starved oil condition since they show lower coefficient of friction.

The use of Shadowgraph and Schlieren optical systems is a simple method to determine flow patterns of heated air external to the vehicle at idle. In particular, the method can be used to visualize natural convective air flow patterns at the underbody to aid in heat shielding design. Moreover, air recirculation patterns around the front end of the vehicle can be visualized without the use of smoke. The optical equipment is described and recommendations proposed for setting up the equipment. A video tape of some results is also presented.

Many suppliers and OEMs adopted the concept of transmissibility ratio as a method of choice to evaluate the NVH performance of cylinder head cam covers. The was defined as the transfer function between the cam cover and the cylinder head average vibrations. The was shown to be independent of the engine speed and declared to be a characteristic intrinsic to the cam cover system. This paper examines the correlation between the predictions and the measured cam covers sound power. For this purpose, a comprehensive study was conducted using several cam covers with different materials, designs and isolation systems. The results indicated a moderate correlation between the and the sound power for the isolated covers only. Analysis of the measured cam cover and cylinder head vibrations shows the potential cause for this weak correlation and demonstrates the need for improving the definition in order to accurately guide the cam cover NVH design.

This paper benchmarks some methods of nondestructive testing for zero and high mileage spot weld quality/integrity and degradation evaluation (pin holes, voids, cracks, fatigue, corrosion, etc.). The methods include X-ray radiography, ultrasonic imaging, ultrasonic pulse/ echo, pulsed infrared or thermography, and laser/TV holographic interferometry imaging. The advantages and limitations of each method are provided with descriptive principles and real test examples. It is found that X-ray radiography combined with ultrasonic echo technique is the most favorable one considering time and cost for the current zero and high mileage spot weld evaluation.

The 1997 Ford Explorer introduces a new two valve single overhead cam (SOHC) version of the 4.0L V6 engine. Maximum power output is increased to 153 KW net (205 HP) at 5000 rpm and 340 N-M of torque (250 lb-ft) at 3000 rpm, which represents a 28% increase in power and an 11% increase in torque over the existing 4.0L overhead valve (OHV) design. The new design's performance features are single overhead camshafts driven by a patented “Offset Y-drive” dual stage chain system, a plastic variable induction system, and aluminum cylinder heads. For quieter and smoother operation, a main bearing ladder frame and a unique second-order balance shaft (4x4 only) are added.

This book draws upon a variety of the author's experiences during more than 25 years in automotive safety. It gives an introduction to plain film radiographs (x-rays), computed tomograms (CTs), and magnetic resonance images (MRIs) such that vehicle safety professionals can use these techniques to help piece together the puzzle and provide a better understanding of the relationship between vehicle crash scenarios and occupant injury. For those with a primarily vehicle background, Neck Injury provides an overview of how x-rays, CTs, and MRIs may be used as a source of information to help analyze vehicle crashes and the associated injuries. For those with a clinical background, the book provides insight into how injuries relate to the vehicle crash. Chapters cover: Anatomy Imaging Injuries and Injury Mechanisms

A new turbocharged 60° 2.7L 4V-V6 gasoline engine has been developed by Ford Motor Company for both pickup trucks and car applications. This engine was code named “Nano” due to its compact size; it features a 4-valves DOHC valvetrain, a CGI cylinder block, an Aluminum ladder, an integrated exhaust manifold and twin turbochargers. The goal of this engine is to deliver 120HP/L, ULEV70 emission, fuel efficiency improvements and leadership level NVH. This paper describes the upfront design and optimization process used for the NVH development of this engine. It showcases the use of analytical tools used to define the critical design features and discusses the NVH performance relative to competitive benchmarks.

In modeling of engine fuel-air mixing, it is desired to be able to predict fuel spray atomization under different injection and ambient conditions. In this work, a previously developed sheet atomization model was studied for this purpose. For sprays from a pressure-swirl injector, it is assumed in the model that the fuel flows out the injector forming a conical liquid film (sheet), and the sprays are formed due to the disintegration of the sheet. Modified formulations are proposed to estimate sheet parameters including sheet thickness and velocity at the nozzle exit. It was found that the fuel flow rate of a swirl injector satisfied the correlation well. Computations of correlation well. Computations of the sprays injected in an engine with a side-mounted injector were performed for conditions that duplicated a set of experiments performed in an optical engine. The computed results were compared with the spray images obtained from the optical engine using elastic (Mie) scattering.

Work has been performed to study side glass vibrations of a typical automobile using a scanning laser vibrometer. The objective of this work was to achieve better understanding of the source and path mechanisms for aeroacoustically generated wind noise. As a tool for measuring aeroacoustically generated vibrations, the laser vibrometer presents many advantages over traditional methods. These advantages, discussed in this paper, include rapid setup, full field imaging, high spacial resolution, non-contact operation, and wide dynamic and frequency ranges.

The development, evaluation, and selection of Plasma spray powder material for the coating of aluminum-alloy engine cylinder block bores was conducted to yield a bore system which provides numerous benefits relative to the present cast iron sleeve system. These include: a reduction in ring/bore wear, friction, and in engine oil consumption as well as a benefit in reduced corrosion. A reduction in engine weight, overall costs, and improvements in machining and honing operations are shown. Alternate thermal spray processes are also described in this investigation. Test evaluation leads to the selection of two plasma powder material spray systems. One system emphasizes low cost relative to the present system. The second system provides significant reduction in friction and ring/bore wear through the introduction of solid lubricant in the material composition.

While weight reduction in automotive design and manufacturing has been on-going for several years, in the area of powertrain technology lightweighting has been a difficult challenge to overcome due to functional requirements, as well as material and manufacturing constraints. The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefit and fuel reduction.