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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.

The cold-weather driveability performance of some European cars deteriorated in the early 1970s as a result of attempts to improve fuel economy and reduce exhaust emissions. Consequently, a test procedure was developed for rating the driveability performance of European cars equipped with manual chokes and manual transmissions so that the effects of ambient temperature and fuel volatility could be assessed. This procedure and its development are described and the effects of fuel quality, ambient temperature and engine hardware on the performance of European cars are discussed.

The spark-Optimizer is a closed-loop type electronic control device that continuously corrects the ignition timing; in effect it re-tunes the engine some ten times every second. In contrast to the better known pre-programmed controls, the Optimizer is an adaptive type system, in which the output influences the input. By providing the correct spark timing all the time, the Optimizer reduces fuel consumption considerably. This paper describes the spark-Optimizer in its advanced version including recent improvements, like biasing. A comparison with other electronic spark control devices show its superiority in accuracy, flexibility, simplicity, and production costs. Samples of test results show considerable fuel savings with the Optimizer.

Proper choice of feedback control strategy is not the only consideration in the feedback fuel delivery systems. Open loop strategies and design of control electronics effect system performance. A basic description of the system and interactions with the electronic control will be presented.

Calibration gases are an essential element of pollution measurement. Their importance is emphasized because calibration errors are translated directly to the measured data. The concept of a calibration gas department responsible for filling the needs of all exhaust emission test facilities within an organization is a proven method for improving accuracy and precision, reducing test variability and assuring complaince with the law. Centralized handling of zero and span gases for multiple test sites within a facility is cost effective. In our case, installation costs were paid back in less than a year from the savings in product cost, cylinder rental and material handling.

The ambient conditions in the test facilities, the dynamometer characteristics, and the test drivers influence the formation of the components in vehicular exhaust gas emissions. To quantify the specific effects a standard test vehicle which is equipped with a mechanized driver and a measuring system is used as a calibrating instrument. Variations of the barometric pressure were found to influence the exhaust test results significantly. Systematic errors up to a factor of two may be caused by malfunctions of apparently well-adjusted dynos. Furthermore, the drivers can create large deviations without violating the tolerances of the driving schedule.

This paper reviews studies in Europe during the summer of 1977 to investigate the possibility of expanding gasoline supply through relaxation of existing Reid Vapor Pressure (RVP) volatility specifications. Performance parameters investigated included vehicle vapor lock and hot weather driveability under both controlled and consumer operation. Overall, it appears that some existing RVP specifications could be relaxed and still provide satisfactory consumer protection levels. This would permit more optimum utilization of available high volatility, high octane gasoline components and expand gasoline product yields while minimizing crude requirements.

A multi-cylinder four stroke cycle spark ignition engine equipped with an exhaust gas recirculation (EGR) system to reduce nitric oxide emission has been comprehensively simulated in a computer program including intake and exhaust manifolds. The program was tested against experiments performed on a standard production four cylinder four stroke engine equipped with a simple laboratory made EGR system. A nitric oxide emission reduction of about 50% was obtained at the peak NO condition. In spite of simplified assumptions the comparison between prediction and measurement of some major engine variables was good. The simulation program holds promise as a tool for engine development work. An appendix is added giving the outline of the calculation procedure.

Data acquired from extensive studies concerning the driving behavior in European cities were analyzed and compared to driving cycles used in exhaust emission testing. The US 72 cycle is found to be a good approximation, nevertheless it should be modified. Especially its total duration and its feasibility to weight the engine warm-up phase must be optimized. An improved driving cycle based on the US 72 cycle was developed which lasts 445 seconds. This cycle should be repeated once - using separate CVS sampling bags - so that the influence of the warm-up phase can be taken into account.

Well in excess of a trillion passenger miles are driven each year in the U.S. in vehicles employing conventional brake fluids based on glycols, glycol ethers, alcohols, polyglycols and other closely related components. The ways in which these components are assembled offer an extremely wide array of physical properties and performance characteristics in a vehicle's braking system. This paper discusses the range of physical properties and performance characteristics attainable in conventional brake fluid formulations. The laboratory data is supplemented with field testing data.