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This is an assessment of current two-stroke automotive engine technology, implementation policy, vision, goals, and engine development and commercialization strategy. It includes a historical review of key two-stroke Otto cycle and Diesel cycle engine developments, a summary of the specifica-ions for the new: Toyota S-2 gasoline and S-2 Diesel engines, Suburu Super 2-stroke, Orbital two-stroke engine series, and Industrial Technology Research Institute (ITRI) two-stroke technology in Taiwan. Although two-stroke engine technology has been under development since the end of the 19th century, currently the only mass produced vehicles powered by two-stroke cycle engines are the Trabant and Wartburg, with 594 cc two cylinder and 993 cc three cylinder engines, respectively, essentially unchanged in cylinder configuration and porting since 1931.

This is a descriptive review of the ceramics structural applications developed by Isuzu, Mazda, Nissan, Toyota and General Motors in spark ignition, Diesel and gas turbine automotive engines; new analytical procedures needed for the design of structural ceramics; new silicon nitride ceramics with strength of material properties approaching steel; new ceramics processing techniques which have been reduced to commercial practice in Japan on a mass production scale; and tests of vital structural components fabricated of these ceramics.

This is an assessment of alternative propulsion technology options presently under investigation for potential application to automobile propulsion in the 1990's. It includes a brief review of key aspects of the new US DOE National Energy Strategy, as recommended to the President in March 1991, and the impact on future automotive propulsion policy choices in the immediate future. Also considered is the impact of the decision by the California Legislature, in the 1990-91 State Budget, which directed the Department of Transportation (Caltrans) to expand the assessment and policy support for improvements in transportation technology. In addition, key technical aspects of the prime mover options currently under development around the World are shown. Among these options are: ceramic piston engine dynamic structural components for conventional four-stroke engines, ceramic gas turbines, new two-stroke engines, and electric propulsion.

The Experimental Safety Vehicle powertrain and fuel system developed by General Motors in compliance with Contract DOT-OS-00095 with the U.S. Department of Transportation include several special features: a low engine accessory package to meet the front visibility down angle of 8 degrees, engine and transmission mounting for retention at high decelerations, a light aluminum engine, an over-the-rear-axle fuel tank, and a unique evaporative emission fuel pipe routing. A comprehensive test program was planned and final testing to validate contract specifications was conducted.

The development of a plasma jet ignition system is described on a 4-cyl, 140 in3 engine. Performance was evaluated on the basis of combustion flame photographs in a single-cylinder engine at 20/1 A/F dynamometer tests on a modified 4-cyl engine, and cold start emissions, fuel economy, and drivability in a vehicle at 19/1 air fuel ratio. In addition to adjustable engine variables such as air-fuel ratio and spark advance, system electrical and mechanical parameters were varied to improve combustion of lean mixtures. As examples, the air-fuel ratio range was 16-22/1, secondary ignition current was varied from 40 to 6000 mA, and plasma jet cavity and electrode geometry were optimized. It is shown that the plasma jet produces on ignition source which penetrates the mixture ahead of the initial flame front and reduces oxides of nitrogen emission, in comparison to a conventional production combustion chamber.

This is a technological assessment of alternate piston engine cylinder and crankshaft configuration alternatives. The balance characteristics of automotive engines have been generalized here in terms of four mathematical expressions which describe the unbalanced forces and moments of a piston engine as functions of the number of cylinders, vee angle, crankshaft configuration and cylinder bank offset. These unique relations permit any inline, vee and opposed engine to be evaluated for balance. And, this made it possible to identify all of the inherently balanced configurations with uniform radially spaced crank throws, for any cylinder vee angle and for any crank configuration with up to 24 cylinders.

This is a technological assessment of alternate engine component configuration and material alternatives. It includes a comparative analysis of key characteristics of Gasoline, Diesel and Gas Turbine engines built by Daihatsu. Honda, Isuzu, Mazda, Mitsubishi, Nissan. Suburu. Suzuki and Toyota. The piston engines range from two to ten cylinders with inline, vee and opposed configurations. Furthermore, additional special features and alternative choices include variable compression ratio, ceramic structural components, supercharger, turbocharger, twin turbocharger, supercharger-turbocharger combined and the regenerative gas turbine.

This study identifies the ambient conditions under which a so-called empty-Boeing model 747-131 fixed wing jet center wing tank (CWT), containing a residual fuel loading of about 3 kg/m3, less than 60 gallons of aviation kerosene (JetA Athens refinery jet fuel), could form hazardous air/fuel mixtures. The issues are limited to explosion safety concerns relating to certificated fixed wing jet aircraft in scheduled passenger service. It is certain that combustible mixtures do not exist in a fuel tank containing JetA type fuel at ambient temperatures below 38°C (100°F), the lean limit flash point (LFP) for jet fuel at sea level. Never the less, the original study by Wyczalek and Suh (1997), identified six rational conditions which can occur and permit hazardous mixtures to exist in a fuel tank.

The specific mission was to determine the effect of driving schedules on the efficiency of battery powered electric vehicles (EV) and hybrid engine/electric vehicles (HEV). Efficiency was referenced to the hydrocarbon (HC) fuel source which provided the electrical energy. In the case of the battery powered pure electric vehicle, the HC source was referenced to the public utility HC fuels. While, in the case of hybrid electric vehicles, the HC source was carried on board the HEV in the vehicle fuel tank.

Battery electric propulsion presents opportunities to regeneratively recover vehicle kinetic energy and provide: unique integrated regenerative braking options singly and/or in combinations; to further improve vehicle energy economy by methods which are not inherently applicable to the conventional internal combustion powered automobile. There are three basic modes to be considered in the design of regenerative braking systems for battery electric vehicles: service braking, programmable deceleration, and emergency braking. Furthermore, the type of traction motor, the driving schedule, and charging characteristics of the associated battery pack are essential considerations involved in designing regenerative braking systems for optimal recovery of vehicle kinetic energy and optimizing battery pack life.

Battery electric propulsion presents opportunities to recover vehicle kinetic energy and provide: unique integrated regenerative braking options singly and/or in combinations; to further improve vehicle energy economy by methods which are not applicable to conventional internal combustion powered vehicles. There are three basic modes to be considered in the design of regenerative braking systems for battery electric vehicles: service braking, programmable deceleration, and emergency braking. Furthermore, the type of traction motor, the driving schedule, and charging characteristics of the battery pack are essential considerations involved in designing regenerative braking systems for optimal recovery of vehicle kinetic energy and optimal battery pack life.