Search Results

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.

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 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 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.

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.