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Texas Tech University (TTU) was one of sixteen universities competing in EcoCAR:-The Next Challenge competition. It is a three year collegiate advanced vehicle technology competition where teams are challenged to re-engineer a General Motors(GM) donated vehicle to achieve improved fuel economy and reduced emissions while maintaining consumer acceptability in the areas of stock performance, utility and safety. Two-mode hybrid which is an electrically variable transmission was selected as the Texas Tech team's architecture. The first year of the competition emphasized vehicle design through Powertrain System Analysis Toolkit (PSAT) software. The vehicle design parameters were established through vehicle technical specifications(VTS), development of software-in-the-loop (SIL) and hardware in-the-loop (HIL) techniques, rapid control system prototyping and components selection and sizing.

A literature search to identify deleterious effects of using re-refined oil did not disclose any validated occurrences. Significant engine testing using re-refined lubricating oil is reported and no cases were discovered in which engine operation was affected negatively by the use of re-refined oil. The American Petroleum Institute (API) allows the use of re-refined base stock oils in the blending of end use lubricants. Based on oil sample testing performed in this research as well as other authoritative sources, it was determined that no significant chemical or physical differences exist between re-refined and virgin oils. Differences noted in this research were related to higher levels of poly-nuclear aromatics (PNA's) in the re-refined oil. PNA's are formed due to the extreme conditions of temperature and pressure during operation of an internal combustion engine.

Written primarily for fleet management personnel with purchasing, maintenance, or operations responsibilities, Alternative Fuels: Emissions, Economics, and Performance provides essential information for those who are considering adding alternatively-fueled vehicles to their fleets. Readers will gain a solid understanding of the fundamentals of alternative fuels and the factors that need to be considered when evaluating their use. No prior knowledge of alternative fuels is necessary. Basic information on the various alternative fuels and objective data on the costs of converting, fueling, and operating alternatively-fueled vehicles is covered in this book. Fuel cost, performance, reliability, and availability are addressed. The book also discusses the 1990 amendments to the Clean Air Act and the 1992 Comprehensive National Energy Policy Act.

A single-cylinder, 4-stroke, spark-ignition engine was used to evaluate the effect of oxygen enriched air on engine performance and exhaust emissions. Evaluations were made with both gasoline and natural gas. The oxygen content of the intake air was varied between 20.9% (ambient air) and 25%. The effects of oxygen enrichment were evaluated in terms of power output, specific fuel consumption, fuel conversion efficiency, exhaust gas temperature, and exhaust emissions (carbon monoxide and hydrocarbons). Test results indicate that the use of oxygen enriched air produces a significant increase in power output, improved fuel conversion efficiency, lower specific fuel consumption, higher exhaust gas temperature and a substantial reduction in carbon monoxide and hydrocarbon emissions when the engine is fueled with either gasoline or natural gas.

Mechanical Engineering students at Texas Tech participated in the 1989 SAE Methanol Marathon in which a 1988 Chevrolet Corsica was converted to run on M85, a blend of 85% methanol and 15%hydrocarbon fuel. This report describes modifications to the Corsica accomplished in preparation for the continuation of this program, the 1990 SAE Methanol Challenge. The modified Corsica place second overall. In response to the 1990 program requirements, the Corsica was modified to enhance engine, transmission, and suspension performance. Engine modifications include improving cylinder head flow efficiency, changing cam profiles, modifying the engine bore and stroke, using lighter weight pistons with modified rings, using roller-tip rocker arms, enlarging the exhaust runner ports, and installing a specially developed catalytic converter system. The transmission was modified with a lower ratio fifth gear and the suspension was strengthened.

Students and faculty of the Mechanical Engineering Department at Texas Tech University have developed two add-on devices that can significantly reduce pickup truck drag without limiting vehicle utility. One device is a wing structure mounted behind the top rear of the cab; the other device is a cover over the rear portion of the pickup bed. Both devices have demonstrated 5% to 6% drag reductions. Further, the rear bed cover reduces vehicle lift by 30%. Most significant, scale model tests have indicated drag reduction on the order of 17% and lift reduction of 30% when the wing and bed cover are used together. Work to date has involved scale model tests in a low speed wind tunnel and full scale tests in the Lockheed wind tunnel. In addition, computational fluid dynamic studies have been performed to aid in designing the test program and interpreting the test results.

This paper describes the computational technique used to predict flow over and through the front end of vehicles; this scope includes flow over the hood, around air dams, through condensers, radiators, fans, and in the engine compartment. The computational procedure, employed is a finite-difference method for solving time-averaged equations for turbulent flow using the κ-∈ model. A two-dimensional program was modified to add variable-depth cells (in the direction of car width) so that some three-dimensional features could be included. A turbulence model was used which is applicable to rotational and irrotational areas of the flow field. The total system model was calibrated with wind-tunnel data, and various modifications to the vehicle configuration were studied. Results from the predictions were compared with wind-tunnel test data.