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Elemental Composition Determination and Stoichiometric Air-Fuel Ratios of Gasoline Containing Ethanol

General Motors Corp-Leslie Melkvik
Furey & Associates LLC-Robert Furey
Published 2010-10-25 by SAE International in United States
Carbon, hydrogen and oxygen are major elements in modern fuels. Varying combinations of these elements in motor fuel alter the stoichiometric air-fuel ratio (A/F). Stoichiometric A/F ratio is an important parameter in engine calibration affecting vehicle performance, emissions and fuel economy.With increasing use of ethanol in automotive fuels in recent years, since it can be made from renewable feedstocks, oxygen contents in fuel are increasing. Oxygen contents can be around 1.7 mass % in European E5 gasoline or 3.5 mass % in U.S. E10 gasoline and up to 29 mass % in E85 fuel. The increase in oxygen content of fuel has resulted in changes in other physical and chemical properties due to the differences between ethanol and hydrocarbons refined from fossil oil. A previous paper (SAE 2010-01-1517) discussed the change in energy content of automotive fuel and the estimation of net heating values from common fuel properties. This paper will discuss the estimation of elemental composition and stoichiometric A/F ratios of gasoline-ethanol blends from common fuel properties. While the carbon, hydrogen, and nitrogen contents…
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Robust On-Board Engine Oil Monitoring. 2. Determination of Initial Oil Quality and Oil Aeration from Electrical Resistivity and Permittivity

General Motors Corp-Ion C. Halalay, Eric W. Schneider
Published 2009-11-02 by SAE International in United States
Electrical ac impedance measurements were used for tracking the time dependence of the electrical properties (resistivity and permittivity) for 18 fully formulated engine oils during two types of engine dynamometer tests: high-temperature high-load (HTHL) and postal cycle (PC). The signatures in the time dependence of the electrical resistivity of engine oil at beginning-of life (BOL) and during early service differentiate both oil service classifications and test/driving conditions. The air content in engine oils can be determined quantitatively from the permittivity with a detection limit of 0.2 vol%. The significance of our results and their consequences for on-board monitoring of engine oil through sensing technology based on electrical ac impedance measurements are discussed.
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Lean NOx Trap Aftertreatment Technology Impact on Engine Oil Dilution

General Motors Corp-G. Cipolla, A. Chianale, A. Leo
Dipartimento di Ingegneria Meccanica per l'Energetica — Università di Napoli Federico II — Napoli — Italy-M. Cardone, A. Senatore, D. Buono
Published 2009-09-13 by Consiglio Nazionale delle Ricerche in Italy
Euro 6 European legislation emission limits, expected to be introduced around the 2014 timeframe, Lean NOx Trap (LNT) Aftertreatment technology is today considered one the of candidate technology to allow diesel Engine to meet the future Euro 6 limit.The working principle of the LNT is based on its capability to store the NOx engine out during the normal lean (excess of Oxygen) phase operation condition of the Diesel engine. The NOx will be then reduced in a dedicated regeneration phase which consist in creating for relatively short time a rich exhaust gas condition inside the LNT.The LNT regeneration strategy lead to run a Diesel engine with a rich mixture out of the combustion as a Gasoline engine. This can be obtained using advanced air and fuel management. The fuel management implicate the use of delayed injections (after and/or post injections) which can have a direct impact on oil dilution.In this paper, an experimental assessment of the additional oil dilution phenomenon, potentially introduced by the LNT application, was proposed. The first step of the work was…
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Safety Belt Buckle Environment in Vehicle Rollover Crash Tests

SAE International Journal of Passenger Cars - Mechanical Systems

General Motors Corp-Michael J. Haldenwanger, Antonio Antonucci, Gerald A. Cooper, William A. Malopolski, Jennifer L. Sevigny, James P. White, Jack K. Yee
  • Journal Article
  • 2009-01-1251
Published 2009-04-20 by SAE International in United States
A study was conducted by General Motors (GM) to further expand upon the currently available research regarding the safety belt buckle environment during full scale vehicle crash tests. A previous study by GM [1] focused on the environment experienced by safety belt buckles in planar, non-rollover, vehicle crash conditions. This study expands upon that work by measuring buckle acceleration and webbing tension in a variety of full scale vehicle rollover crash tests. A variety of test vehicles, rollover crash types, seating positions, roll directions, test speeds, and safety belt systems were included in the study. Emphasis was placed on examination of the buckle response data during vehicle-to-ground impacts (roof, body, and wheel).This study reports on data recorded from 20 full scale rollover crash tests with 40 instrumented end release safety belt buckles. Crash tests in this study were limited to rollover tests involving un-tethered vehicles where at least one-quarter turn or more occurred. Acceleration measurements were made using tri-axial accelerometers mounted onto the buckles. The accelerations were recorded in the axial, lateral, and perpendicular axes…
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Low-Cost Air Estimation

SAE International Journal of Engines

General Motors Corp-Oguz Dagci, Man-Feng Chang
SimuQuest Inc-Raymond Turin
  • Journal Article
  • 2009-01-0590
Published 2009-04-20 by SAE International in United States
The focus of this paper is an air charge estimator for engine control system applications which do not feature a mass air flow (MAF) sensor. The proposed approach, beyond its independency of a MAF sensor, is designed to be compatible with the confines of a typical production control system configuration. The air charge estimation algorithm is based on mean-value models for the manifold pressure dynamics and the gas flows through the throttle and valve orifices. It involves nominal static models for the volumetric efficiency of the engine and for the throttle discharge coefficient. The static models for those parameters are complemented with correction factors that are adjusted on-line. The update of the volumetric efficiency correction is implemented in the form of a Kalman-filter which uses the difference between the measured and the modeled manifold pressure as an error metric. The discharge coefficient correction, on the other hand, is implemented in the form of an adjustable correction look-up table. The adjustment of the correction table evolves as a function of the operating condition and is based…
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CFD Simulation of NASCAR Racing Car Aerodynamics

General Motors Corp-Rajneesh Singh
Published 2008-04-14 by SAE International in United States
This paper presents the results of a study of CFD simulation of NASCAR's Car of Tomorrow (COT). Aerodynamic flowfield and forces are computed to investigate effects of moving ground and rotating wheel conditions. Mesh dependence and convergence behavior of various forces is also analyzed to develop an accurate analysis process. Thereafter, the analysis process is applied to compute effects of various design changes of the baseline COT.CFD analysis showed that the lift on the COT decreases due to the moving ground and rotating wheel (MVG&RW) effects. However the drag increases, in contrast to the typical observations for passenger cars. This was attributed to smaller interaction of the underbody flow with the wake flow. The aerodynamic force increments for design changes showed that MVG&RW may not be required to estimate effects of some of the design changes.
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Ejection Mitigation in Rollover Events - Component Test Development

General Motors Corp-Bridget M. O'Brien-Mitchell, Robert C. Lange
Published 2007-04-16 by SAE International in United States
Although rollover crashes represent a small fraction (approximately 3%) of all motor vehicle crashes, they account for roughly one quarter of crash fatalities to occupants of cars, light trucks, and vans (NHTSA Traffic Safety Facts, 2004(1)). Therefore, the National Highway Traffic Safety Administration (NHTSA) has identified rollover injuries as one of its safety priorities. Motor vehicle manufacturers are developing technologies to reduce the risk of injury associated with rollover collisions.During a series of rollover sensor development tests conducted by General Motors, data was collected and analyzed to identify the required load and energy absorption characteristics of the ejection mitigation device used. General Motors then derived from that data a component level test that can be used to evaluate the potential of a rollover capable side air bag to mitigate the likelihood of ejection in a majority of rollover tests. This paper describes the development of the component level test as well as a subsequent assessment of the test parameters in a fixture-level evaluation.
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Continuously Variable Transmission (CVT)

General Motors Corp-John R Maten
BorgWarner Inc-Bruce D Anderson
  • Progress In Technology (PT)
  • PT-125
Published 2006-03-28 by SAE International in United States
This reference contains the latest knowledge on vehicle development with CVT powertrains, transmission assembly design and performance, and the design and development of the five major components of CVT technology: launch device, variator systems, geartrains, control systems, and lubrication. Building on an earlier SAE publication, the 37 technical papers selected for this book cover updated information on a variety of topics within the area of CVTs. Although this book is not intended to represent the full body of CVT technology, it provides technical presentations and their reference documents, which can lead to discussions covering several topics of interest in CVTs.
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Meeting Tomorrow’s Challenges: The Role of the IC Engine

General Motors Corp-J. Gary Smyth, Roy Douglas
  • Technical Paper
  • 2004-21-0080
Published 2004-10-18 by Convergence Transportation Electronics Association in United States
Since its inception, the internal combustion (IC) engine has undergone continuous improvements with respect to efficiency and performance. Future regulatory and environmental requirements are not only driving still further improvements, but also extending the propulsion system efficiency through hybridization and potentially obsolescing the IC engine with hydrogen fuel cells.This paper describes the potential IC engine improvements to meet tomorrow’s challenges and the associated business and technical challenges in obtaining these challenges. The future propulsion system portfolio mix will encompass gasoline engines, diesel engines, hybrids and fuel cells. The critical role of the IC engine in this portfolio mix is examined.
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Development of a Cost Competitive, Composite Intensive, Body-in-White

General Motors Corp-Nancy L. Johnson
Oak Ridge National Laboratory-Raymond G. Boeman
Published 2002-06-03 by SAE International in United States
The Automotive Composites Consortium has initiated the third of a series of focal projects, which is a multi-year program to develop a design and manufacturing strategy for a composite intensive body-in-white (BIW) with aggressive mass reduction, manufacturing cycle time, and cost parity targets. Specifically, the BIW is to exhibit 60% minimum mass savings over the conventional steel baseline, contain the same package space as the baseline, meet or exceed the structural performance, and have cost parity to the baseline in volumes exceeding 100,000 per annum. The Department of Energy's Office of Advanced Automotive Technology provided most of the funding for this project. A design study was undertaken to evaluate whether the mass savings are feasible - utilizing carbon-fiber composites - without sacrificing structural performance. The design was conducted with consideration to cost-effective composites manufacturing processes that are under development. This paper will present objectives of this focused program, results of the design study, and a discussion of the technical challenges that will be addressed during the remainder of the program.
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