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The automobile plays a very important role in the American way of life. The private passenger car has been for generations an expression of a basic American freedom called mobility. In our generation society as a whole, through the federal government, has imposed constraints on the expression of this mobility freedom. These constraints have been imposed in the form of regulations concerning safety, environment and energy. Accordingly, the modern automobile must then be designed to achieve competing objectives in the presence of severe constraints. Discussed here are modern optimization methods which can be useful in this design environment. Included in the discussion are the very powerful Generalized Reduced Gradient and Method of Multipliers algorithms. Mechanical component and system design examples are given which demonstrate the utility of the optimization approach. Particular attention is given to the engine as a major automotive component.

The boundary integral equation (BIE) method has emerged as a promising alternative to the finite element method because in many cases it may significantly reduce the generation and checkout time required to describe the geometry model. Structural analysis is simplified because only the surface of the component being analyzed needs to be defined. Advantages and limitations of the BIE method are discussed. Two example problems are modeled using both the finite element method and the BIE method. One problem is a planar analysis of a gear segment. The other is a three-dimensional analysis of a diesel engine piston.

More plastics than ever before, including thermosetting and thermoplastic, are being utilized for exterior body automotive applications requiring Class A finishes. The subject of meeting Class A finishes is becoming more important as materials such as SMC, BMC, and RIM are more widely used. The scope of the material presented is to discuss some basic requirements necessary to obtain a Class A finish and solutions to common production problems encountered on the finishing line.

After a review on history, market, physical facts of fuel injection follows a short description of present systems. Influences on fuel consumption and emissions, including Lambda-control, are described. Some notes are given on the influence of injection timing, single point injection, combination of fuel injection and ignition to a digital motor electronics. New development trends for less expensive and more effective systems are shown.

The role of NiO in three way catalyst systems is explored with respect to transient oxygen storage and water gas shift activity observed in lean-rich-lean exhaust composition changes. Oxygen storage behavior is observed to playa role in fresh catalyst systems but disappears on aging. However, storage phenomena are still observed in the presence of water and can be explained in terms of water gas shift activity. Nickel containing catalysts in which the nickel is highly dispersed readily form a surface nickel aluminate complex which minimizes oxygen storage and water gas shift capability. A proprietary catalyst which contains stable nickel oxide is capable of maintaining higher activity under transient operation after hydrothermal aging.

Monolithic three-way conversion (TWC) catalysts, at different precious metal concentrations, were aged on an engine dynamometer with fuel doped with lead (0.012 g Pb/gal). These catalysts were subsequently evaluated on an engine dynamometer to examine the effects of air/fuel ratio set point, temperature, and air/fuel ratio amplitude and frequency on the conversion efficiencies for NOx CO and HC. In all evaluations, as the precious metal concentration increased from 5 g/ft3 to 40 g/ft3, the NOx CO and HC conversions increased. Also, the smallest effect of precious metal loading on catalyst efficiency was found at the smallest air/fuel amplitude (±0.3 A/F). The highest overall conversions of NOx CO and HC were obtained at the stoichiometric control point for perturbations of ±0.3 A/F amplitude. Therefore, it appears that a considerable savings in precious metals can be realized if the A/F amplitude of a closed-loop feed-back control system is small (±0.3 A/F).

Comprehensive single-cylinder engine data for three combustion chambers were analyzed statistically in order to quantify the effects of engine operating conditions and chamber geometric variables on combustion characteristics, and of combustion on engine performance stability. Operating condition variables of interest were air-fuel ratio, residual fraction (internal plus external EGR), spark timing, engine speed, and fueling level (trapped fuel per cycle). Geometric parameters of importance were chamber “openness” and squish. Combustion and engine performance stability were found to be related such that engine stability was improved when combustion variations were reduced, as would be expected, and/or when the combustion event was shortened. The combustion, in turn, was affected by both the engine operating conditions and chamber geometric characteristics.

Experimental observations are presented of instantaneous local heat flux at one position on the cylinder head of a motored reciprocating engine. A range of compression ratio, speed, and inlet conditions were covered. The observations clearly show the phase shift between heat flux and driving temperature difference caused by boundary layer work effects. Correlation is briefly discussed.

Alternatives to cadmium plating on fasteners are investigated from the point of view of cost, corrosion resistance, torque/tension relationships and vibration resistance. Conclusions show that these are inter-related and point to the direction to be taken dependant on the criteria of the fastened joint under consideration.

This paper addresses an ongoing research program that describes and provides guidance on the effectiveness, costs, advantages and disadvantages of simulation training for Air Force flying personnel. In the current climate of drastically reduced fuel availability, alternatives must be available to train aircrew members operational mission essential skills. Air Force use of simulation has increased over the past few years. Such a trend is expected to accelerate in the future. In the past, the majority of R&D funding has gone towards development and improvements in simulation engineering technology. Consequently, there have been numerous improvements, however, less attention has been directed towards the ways these improvements could be used by operational training personnel. As a result, the current data base is insufficient to allow making tradeoff decisions concerning training methods, effectiveness and costs. Such issues are addressed by this study and are reported here.

This paper discusses the advances in mechanical fastening made over the last decade. More detailed analyses of the bolted joint have led to a better understanding of the relationships between the working loads imposed on the bolted joint and the stresses felt by the bolt. The induced preload (tension) in the fastener is shown to be the critical factor involved in the static and dynamic reliability of the bolted assembly. The need for more accurate assembly methods to insure good control of fastener tension has resulted in the development of special electronic controls which are being used on the assembly line. Preload loss mechanisms which occur in service were studied, and new fastener locking methods are being evaluated by means of transverse vibration tests. The designer facing the challenge of greater reliability and fuel efficiency has the recently developed fastening technology at his disposal.

A mathematical model is developed to represent an oxidizing catalytic converter in the exhaust system of a spark ignition engine in which the flow is non steady. By using the basic mass transfer, heat transfer and chemical reaction rate equations on the path lines the heat generated at the catalyst surface and the friction factor are allowed for in the generalized non steady flow relations using the method of characteristics. The model is included in a multi-cylinder engine simulation program. Secondary air injection into the exhaust system is represented by a simple mixing process without chemical reaction. A series of tests were carried out on a four cylinder two litre engine with a carbon monoxide and hydrocarbon oxidizing converter and secondary air injection. Comparison of results between experiments and computer calculations shows excellent agreement when the converter is new, but that if the catalyst surface is poisoned or aged the hydrocarbon prediction deteriorates.

This paper reviews piston and ring friction which can account for 65% of the mechanical friction in an internal combustion engine. It shows that cylinder liner lubrication is predominantly hydrodynamic with localized contact between ring and liner at TDC firing. The degree of contact may increase during transient conditions. Piston ring friction in the hydrodynamic region is proportional to the square root of the viscosity. The viscosity is affected by temperature and pressure which can reach peak values of 340°F and 4000 psi, respectively. Gains in fuel economy through viscosity reductions have been reduced in the last 25 years due to changes in piston and ring design.

After the frontal impact, the side impact is the next most dangerous frequently occurring accident mode, accounting for approximately 25 % of all injuries and fatalities. Safety research, therefore, endeavors to determine those parameters of the side impact event, which have a decisive influence on the risk of injury to the occupants. Two parameters are the structural rigidity of the impacting vehicle and of the impacted vehicle. Using a very simple mathematical model the possibilities of vehicle compatibility in side impacts are being investigated in order to reduce the likelihood of injury to the lowest possible level.

This paper describes a technique for developing a computer simulation model of automotive machining processes comprised of machines, conveyors, overhead monorails, and the parts that flow through this system. Employing the discrete-event modeling features of the GASP-IV simulation language, this technique requires that the modeler (a) describe the process configurations in terms of its elements (machines, conveyors, and monorails), (b) provide data inputs that describe the characteristics of each of these elements and define their relationships to one another, and (c) provide data inputs that give the simulation conditions. The model then simulates a prescribed duration of production activity and produces both statistical and graphical reports in terms of production output and operational efficiency. Analysis of simulation trials involving several proposed process configurations, including alternative modes of material handling, enables the selection of a preferred design.

Petroleum marketers traditionally supply gasolines of constant octane quality year-round. However, car octane number requirements are not constant, but vary with atmospheric temperature and humidity. Adjusting octane quality to match seasonal changes in car requirements would result in less octane giveaway during periods of low requirements and would reduce gasoline manufacturing costs for the same year-round satisfaction. Because of problems with exchanges, contract sales, and pipeline fungibility specifications, application of seasonal octane specifications on a widespread basis is not feasible unless they are generally accepted by the industry.

An analytical technique presented in this paper provides the capability to predict the crush response of certain automotive structural components. This technique was coded from the finite difference formulation to solve the highly nonlinear equations of motion of the structural components when subjected to large deformation. It is operational for production usage. As a production program, it has extensive user convenience such as interactive computer graphics in model generation, model editing, and output display. For the purpose of demonstration, four problems solved by using this program will be reported in this paper.

Hybrid vehicles, i.e., those containing two or more sources of power, have the potential of increased fuel economy under certain types of driving conditions. Systems currently being investigated include combinations of heat engines, electric drives, fly-wheels, and accumulators. In order to obtain fuel economy improvements over conventional vehicles, efficient components are required as well as a good system design. Hybrid powerplants appear more promising for heavier vehicles.

The art and craft of tunnel boring discusses the evolution of mechanized tunnel construction from prehistoric to modern times. Specific technical achievements and notably innovative projects are described. The modern boring machine and the optional methods for overcoming varying ground conditions are presented. The conclusion provides a hint for future development trends.

Extensive tests have been carried out with European and Japanese cars to investigate the occurrence of vapour lock and related problems under hot-weather conditions. Different criteria, based on gasoline inspection properties, were evaluated for their ability to control hot-fuel handling performance. Considerable market experience has been accumulated with the flexible control, RVP (mbar) + 7E70, which is preferred by the authors to the vapour/liquid ratio type of control because it is far easier to use in routine refinery applications and control. However, the two types of control are equivalent in their ability to predict the performance of a wide range of gasolines, including those which may result from reductions in lead content. In their tolerance to gasoline volatility, the European and Japanese cars are very similar to the catalyst-equipped California models tested by the CRC in 1975.