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Diagnostic tools and service information are often viewed and developed as separate tools for the automotive technician to use while repairing a vehicle. However, the service technician often uses both of them interactively when diagnosing and repairing a problem on a vehicle. Expert-system technology and electronic information retrieval technology are available to create tools that will help technicians improve their efficiency. However, the ultimate advantage of these technologies is not realized until the two applications are linked together so that they can be used interactively. Selecting the appropriate technologies and linking them together as an integrated system is critical to the ultimate effectiveness, acceptance, and success of the system.

High speed tires were measured on the road and in the lab, both on a rear wheel drive and a front wheel drive vehicle. The tests described refer to standard methods used in the tire industry. They include various tire patterns as well as direction-oriented patterns. Depending upon vehicle type and driven axle, the subjective test result in varying sequences in the main groups of tested parameters - slalom, curve behaviour, handling characteristics and steering response. Static, quasi-static and dynamic measurements on tires were performed in the Semperit lab. The data obtained in the lab did not result in distinct sequences. In case we have to decide which tire is best suited for the intended purpose, the basis for decisions in neither precise nor clear, and conventional engineering mathematics will not suffice. Therefore, “Fuzziness” has to be introduced. The basis of the Fuzzy-Set-Theory is a maximum/minimum principle.

Safety systems must have sound structural performance and, as safety performance targets and vehicle complexity rise to ever higher levels, the impact performance of vehicle structures comes under microscopic scrutiny. Full scale crash tests are used to demonstrate the impact performance of a vehicle's structure but the required number of expensive prototypes may not be available in the early stages of any vehicle programme. Hence a means is required to develop the structural performance under impact loading by using the minimum number of vehicles without reducing quality and performance or increasing costs and development timescales. Based on its experience of crash technology, MIRA has designed, developed and installed a new tool to address this issue, in the form of a barrier load cell array with significantly increased geometric resolution and superior data processing, called the Microcell Barrier.

Modeling and simulation have become integral parts of the engineering process and will assume an even greater role in the years ahead. DoD initiatives like Simulation-Based Acquisition mandate a central role of simulation in systems design and engineering. As system engineers and designers rely increasingly on simulation to address design issues, there is an increasing need to develop integrated simulation and modeling environments to support human factors analysis. This paper addresses how and why it would be beneficial to link human process models to human figure models. We discuss how the linked models promote visualization of human factors design concepts. For example, capturing timing and error information from a human figure model greatly enhances the validity of the human process model. Likewise, using human process models to represent the aspects of the process that do not require a human figure model allows larger, more complex processes to be modeled.

Measurements of the initial values lead to an inverse and mathematically unprecisely formulated problem. A precise definition of an inverse problem is possible. It is to state a mathematical model of a physical process with clearly defined initial and exit values for the system behind the process. One can grasp the idea of an inverse problem by considering the tire as a copy of the objects of nature in a room with observations. Interpretation of nature is generally a result of an inverse problem. On one hand, the tire may be represented through the sensory organs and the nervous system as well as the experiences of the developer''s existing apparatus of the projection of reality. On the other hand, it may be represented by a physical law or a model that can be confirmed or is to be refuted with teh help of suitable measurements.

Polyurethane foam is often a major constituent of automotive seating, and exhibits highly nonlinear behavior under normal operating conditions. Efficient design requires an understanding, as well a good model, of the foam behavior. The work presented here is an attempt to link continuum and microstructural approaches to modeling foamed materials and take advantage of the utility in each. The outcome will ultimately be the ability to generate a foam superelement that is sensitive to microstructural properties but does not require the computational complexity of a microstructural finite element model. This will facilitate the iterative design of seating for comfort and other dynamic considerations. To this end, an Ogden-type continuum model for compressible rubber-like solids, is fitted to the results of numerous simulated compression tests conducted on finite element models of two-dimensional foam.

The formation of deposits within injector nozzle holes of common-rail injection fuel systems fitted to modern diesel cars can reduce and disrupt the flow of fuel into the combustion chamber. This disruption in fuel flow results in reduced or less efficient combustion and lower power output. Hence there is sustained interest across the automotive industry in studying these deposits, with the ultimate aim of controlling them. In this study, we describe the use of Scanning Electron Microscopy (SEM) imaging to characterise fuel injector hole deposits at intervals throughout an adaptation of the CEC Direct Injection Common Rail Diesel Engine Nozzle Coking Test, CEC F-98-08 (DW10B test)[1]. In addition, a similar adaptation of a previously published Shell vehicle test method [2] was employed to analyse fuel injector hole deposits from a fleet of Euro 5 vehicles. During both studies, deposits were compared after fouling and after subsequent cleaning using a novel fuel borne detergent.

The rear end geometry of road vehicles has a significant impact on aerodynamic drag and hence on energy consumption. Notchback (sedan) geometries can produce a particularly complex flow structure which can include substantial flow asymmetry. However, the interrelation between rear end geometry, flow asymmetry and aerodynamic drag has lacked previous published systematic investigation. This work examines notchback flows using a family of 16 parametric idealized models. A range of techniques are employed including surface flow visualization, force measurement, multi-hole probe measurements in the wake, PIV over the backlight and trunk deck and CFD. It is shown that, for the range of notchback geometries investigated here, a simple offset applied to the effective backlight angle can collapse the drag coefficient onto the drag vs backlight angle curve of fastback geometries.

Liquefaction is one approach for increasing the density of natural gas and hydrogen to make them practical motor vehicle fuels. Productive on-vehicle utilization of the “cold energy” invested in these fuels by the liquefaction process is investigated. This “cold energy” enthalpy change is approximately 1.7% and 3.2% of the lower heating value of LNG and LH2, respectively. Direct utilization for truck cargo cooling and engine charge densification has been demonstrated. Indirect utilization involves power generation to drive vehicle auxiliary equipment. The maximum power is limited by the thermodynamic availability, which can exceed the “cold energy” enthalpy change. A system to drive an LNG vehicle high-pressure fuel pump without engine attachments or parasitic power consumption is described. Ethylene in a Rankine cycle receives heat from the engine coolant, direct drives the reciprocating pump, and rejects heat to the LNG.

Natural Gas Vehicle (NGV) engine technology is mainly based on a well-known and already established engine functioning principle, the Otto engine. The recent developments achieved and the OEMs push for this kind of technology clearly shows the confidence and reliability of this technology, especially when it comes to the use of compressed natural gas (CNG). For the above-mentioned reasons, the number of applications involving NGVs has increased worldwide. Environmental and economic reasons, on the whole, have been the main drive for this diffusion. Natural Gas chemical properties are an irrefutable proof of the advanced behavior, environmentally speaking, of a fuel that emits less CO₂ (due to its carbon-hydrogen balance when compared to other fuels) and less NOx and PM. In many countries, favorable taxation schemes have helped the development and entrance into the market of the NGV technology, especially for the light-duty vehicles.

Liquefied natural gas, commonly referred to as LNG, is gaining popularity as an alternate fuel for heavy duty automotive applications. The use of LNG as an alternate fuel for automotive applications is in its early stages and is not yet defined by any standards. While technology improvements are common within the automotive industry, changes in fuel formulation are usually minor and evolutionary in nature. Technology advancement may play a dominant role in defining the LNG fuel standard of tommorrow but, the emergence of LNG as an alternate automotive fuel requires LNG to shed its “cryogenic mystique” and assume properties which can be understood by the automotive user. The two industries, cryogenic and automotive, represent sophisticated, mature technologies, each individually understood within its respective industry.

Liquefied natural gas (LNG) is being developed as a heavy vehicle fuel. The reason for developing LNG is to reduce our dependency on imported oil by eliminating technical and costs barriers associated with its usage. The U.S. Department of Energy (DOE) has a program, currently in its third year, to develop and advance cost effective technologies for operating and refueling natural gas–fueled heavy vehicles (Class 7-8 trucks). The objectives of the DOE Natural Gas Vehicle Systems Program are to achieve market penetration by reducing vehicle conversion and fuel costs, to increase consumer acceptance by improving the reliability and efficiency, and to improve air quality by reducing tailpipe emissions. One way to reduce fuel costs is to develop new supplies of cheap natural gas.

Because fuel accounts for a high percentage of railroad operating costs, interest is developing in a possible alternate fuel, liquefied petroleum gas (LPG). This paper discusses LPG in terms of cost, availability, and methods of adaptation to present locomotive engines.

ALTHOUGH the use of liquefied petroleum gas in automotive vehicles dates back to the early Thirties, it is only in recent years that there has been considerable interest in this application of LPG. The author lists the factors contributing to this increasing interest as follows: 1. Rising operating costs in the bus industry. 2. The increased supply of LPG. 3. The availability of engines of higher compression ratio. The author discusses both the fuel and the vehicles in which it can be used, placing particular emphasis on cost considerations.

The automotive industry is rapidly changing as electric vehicles (EVs) have gained share in the market, bringing new challenges to ensure passenger comfort through noise, vibration, and harshness (NVH) management. Automotive acoustics engineers employ a variety of materials to reduce NVH across the audible frequency spectrum. In general, these materials have been tailored to address vibrations related to internal combustion engines (ICE). For example, liquid applied sound damping (LASD) coatings are widely employed to reduce structural vibrations due to their ease of application and light weight. LASD coatings are typically applied to the vehicle body to reduce structural vibrations at frequencies <1000 Hz, since ICE vehicles tend to exhibit vibrational modes primarily at these frequencies. However, EVs are known to also excite higher frequency vibrational modes up to 3000 Hz.

It is well known that heat generated during vehicle braking affects wear and stopping distances. To improve these conditions, supplemental retarders, such as exhaust brakes on diesel powered trucks and electromagnetic retarders have been used for years. Several of the diesel engines (below 7 Liters) are no longer designed to allow the use of exhaust brakes, and gas powered vehicles do not have that option either. Other options such as electromagnetic retarders are heavy, draw excessive amounts of current, and are a costly installation. To fill the void left by the elimination of exhaust brakes from some of these vehicles, and to provide an option that improves upon the undesirable aspects of electromagnetic retarders, a new technology; Liquid Cooled Disc Brakes, has been developed and designed into a product that fits on most popular truck chassis in the Class 2 - 4 range.

In order to use an electric induction motor to power an automotive vehicle, heat occurred in a motor is an important issue. Generally, an induction motor could be operating at a high load for many extensive periods. The generated heat in motor could cause damage on motor parts subsequently decreasing their useful service life. The objective of this study was to develop a cooling system of the induction motor by introducing liquid coolant passages on a housing part to obtain higher cooling efficiency than that of conventional Totally Enclosed Fan Cooled system (TEFC). Principally, conventional TEFC finned housing and rear fan would be replaced by a cylindrical aluminum housing. Special heat transfer oil was chosen as a coolant mainly due to its dielectric property. The liquid cooling housing geometry was defined by series of cooling passages to guide the liquid coolant through and around the housing. The design of liquid cooling system was performed via computational simulation.

Twisted nematic (TN) liquid crystal display technology has now attained a level of maturity which matches the uncompromising requirements for its implementation in automobiles. Present day performance of TN-LCD’s is analysed in terms of basic intrinsic properties, cell technology performance and polarizer quality. Future developments aim at higher information densities and increased system reliability, they include the incorporation of integrated driver circuits on the glass substrate of the display. Other LC display technologies as e.g. dichroic displays shall become available for dashboards; they greatly profit from the cell technology experience gained through TN-LCDs, yet their performance has still to be improved through progress in LC and dye material research.

This paper describes motor vehicle lamp assemblies employing a mask that controls the photometric output, or cosmetic appearance of the lamp. The mask is comprised of materials such as liquid crystal or electro-optic and electrochromic films or coatings. Such materials exhibit optical anisotropy based on the application of an electric current. A drive circuit is coupled to the mask and controlled by the motorist or a programmable microprocessor. The optical conditions of various sections of the mask are altered by the applied voltage from this controller. The photometry and colorimetric values at any point in the beam pattern can be altered. The mask also can be constructed to produce various cosmetic appearances, including lamp concealment.

A liquid-crystal display using the twisted nematic mode was developed for an automotive instrument panel. A low viscosity, quick response liquid crystal of wide nematic range (−30 to 85°C) was designed with the aid of the molecular theory for viscosity of liquid crystals. A liquid crystal less than 20 cp at 25°C with wide mesomorphic range (−30 to 85°C) was developed. A display with this material gave quick response, about one and one-half seconds at −30°C. For the most uniform response and widest viewing angle, a liquid crystal molecular alignment of low tilt angle was developed. A simple rubbing alignment technique was used which is compatible to glass sealing. A polarizer resistive to high temperature and high humidity was applied. The display can be operated with good performance and high reliability.