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Technical Paper

Neat Biodiesel Fuel Engine Tests and Preliminary Modelling

2007-04-16
2007-01-0616
Engine performance and emission comparisons were made between the use of 100% soy, Canola and yellow grease derived biodiesel fuels and an ultra-low sulphur diesel fuel in the oxygen deficient regions, i.e. full or high load engine operations. Exhaust gas recirculation (EGR) was extensively applied to initiate low temperature combustion. An intake throttling valve was implemented to increase the differential pressure between the intake and exhaust in order to increase and enhance the EGR. The intake temperature, pressure, and EGR levels were modulated to improve the engine fuel efficiency and exhaust emissions. Furthermore, a preliminary ignition delay correlation under the influence of EGR was developed. Preliminary low temperature combustion modelling of the biodiesel and diesel fuels was also conducted. The research intends to achieve simultaneous reductions of nitrogen oxides and soot emissions in modern production diesel engines when biodiesel is applied.
Technical Paper

Resistance Spot Weldability of Three Metal Stack Dual Phase 600 Hot-dipped Galvanized Steel

2007-04-16
2007-01-1363
Fuel economy and federal safety regulations are driving automotive companies to use Dual Phase and other Advanced High Strength Steels (AHSS) in vehicle body structures. Joining and assembly plays a crucial role in the selection of these steels. Specifications are available for the resistance spot welding (RSW) of lower strength sheet steels, covering many aspects of the welding process from the stabilization procedure to endurance testing. Currently, specifications in the automotive industry for RSW with AHSS are limited. It is well known that welding of a thickness ratio greater than 1:2 poses a challenge. To utilize thinner gauge AHSS panels on body-in-white, welding schedules to join the thin to thick sheet steel stack-up are needed. Most of the existing published work was conducted on uncoated sheets and welded to the same thickness.
Technical Paper

A Comparison of the Effect of E85 vs. Gasoline on Exhaust System Surface Temperatures

2007-04-16
2007-01-1392
With concerns over increasing worldwide demand for gasoline and greenhouse gases, many automotive companies are increasing their product lineup of vehicles to include flex-fuel vehicles that are capable of operating on fuel blends ranging from 100% gasoline up to a blend of 15% gasoline/85% ethanol (E85). For the purpose of this paper, data was obtained that will enable an evaluation relating to the effect the use of E85 fuel has on exhaust system surface temperatures compared to that of regular unleaded gasoline while the vehicle undergoes a typical drive cycle. Three vehicles from three different automotive manufacturers were tested. The surface of the exhaust systems was instrumented with thermocouples at specific locations to monitor temperatures from the manifold to the catalytic converter outlet. The exhaust system surface temperatures were recorded during an operation cycle that included steady vehicle speed operation; cold start and idle and wide open throttle conditions.
Technical Paper

Improving Low Frequency Torsional Vibrations NVH Performance through Analysis and Test

2007-05-15
2007-01-2242
Low frequency torsional vibrations can be a significant source of objectionable vehicle vibrations and in-vehicle boom, especially with changes in engine operation required for improved fuel economy. These changes include lower torque converter lock-up speeds and cylinder deactivation. This paper has two objectives: 1) Examine the effect of increased torsional vibrations on vehicle NVH performance and ways to improve this performance early in the program using test and simulation techniques. The important design parameters affecting vehicle NVH performance will be identified, and the trade-offs required to produce an optimized design will be examined. Also, the relationship between torsional vibrations and mount excursions, will be examined. 2) Investigate the ability of simulation techniques to predict and improve torsional vibration NVH performance. Evaluate the accuracy of the analytical models by comparison to test results.
Technical Paper

NVH Refinement of Diesel Powered Sedans with Special Emphasis on Diesel Clatter Noise and Powertrain Harshness

2007-05-15
2007-01-2378
NVH refinement of passenger vehicles is crucial to customer acceptance of contemporary vehicles. This paper describes the vehicle NVH development process, with specific examples from a Diesel sedan application that was derived from gasoline engine-based vehicle architecture. Using an early prototype Diesel vehicle as a starting point, this paper examines the application of a Vehicle Interior Noise Simulation (VINS) technique in the development process. Accordingly, structureborne and airborne noise shares are analyzed in the time-domain under both steady-state and transient test conditions. The results are used to drive countermeasure development to address structureborne and airborne noise refinement. Examples are provided to highlight the refinement process for “Diesel knocking” under idle as well as transient test conditions. Specifically, the application of VINS to understanding the influence of high frequency dynamic stiffness of hydro-mounts on Diesel clatter noise is examined.
Technical Paper

Lubricant Requirements of an Advanced Designed High Performance, Fuel Efficient Low Emissions V-6 Engine

2001-05-07
2001-01-1899
Modern high power density gasoline fueled engines place an ever-increasing demand on the engine lubricant. In this study, it is shown that advances in engine design to increase performance, improve fuel economy and lower emissions have outpaced the development of typical commercial engine lubricants. Advanced designed engines began to experience oil starvation as a result of a combination of driving cycles, oil quality and poor maintenance practices. The cause was traced to excessive increases in borderline pumping viscosity as measured by MRV TP-1 (ASTM D4684). Used oil analysis for MRV TP-1 showed viscosity greatly increased in excess of stay-in-grade requirements and in many cases the crankcase lubricant was solid at the temperature appropriate for its viscosity grade. However, at the same time CCS values were in grade or only slightly (1W grade) elevated.
Technical Paper

An Experimental Study of the Spray Characteristics of Pressure-Swirl Atomizers for DISI Combustion Systems

2001-05-07
2001-01-1974
This paper presents results from a comprehensive experimental study of high-pressure pressure-swirl gasoline injectors tested under a range of simulated operating conditions. This study encompassed photographic analysis of single spray sequences and simultaneous measurement of axial velocity, radial velocity and diameter at point locations using the phase-doppler technique. The combination of these measurement techniques permitted an insight into the fluid dynamics of the injected spray and its development with time. Five primary stages in the spray-history were identified and numerated with experimental data.
Technical Paper

An On-Board Reductant Delivery System for Diesel Aftertreatment

2001-09-24
2001-01-3622
It has become evident that almost all diesel aftertreatment devices dealing with NOx and particulate matter (PM) controls require the addition of one or more reducing agents (reductants), such as diesel fuel, ammonia, or aqueous urea to enhance their efficiency and durability. These reductants can be used to catalytically convert NOx to N2, to enrich the air fuel ratio (A/F), or to increase temperatures for regenerating PM filters or for de-sulfating NOx traps. A number of injection methods have been developed recently to provide easy reductant addition. However, many of them may be cumbersome, costly, or ineffective. This paper describes a new reductant delivery system, which appears to minimize these shortcomings. To be effective, the manner of reductant injection into the exhaust is critical. First, the reductant must be added quickly to accommodate the fast transient operations.
Technical Paper

Subcompact Sport Vehicle Development

2001-03-05
2001-01-3817
Considering that the sport cars versions are normally derived from medium car segment, the big challenge in this program was to transform one subcompact in a real sport car. With the focus at the consumer that looks for performance and enjoys sporty driving in conjunction with project financials and competition data the preliminary content was established together with all involved areas, Marketing, Finance, Manufacturing and Quality. Based on the items that indicate high performance, the items considered mandatory or desired by the customer and items detected by Quality research including internal indicators and external indicators, ICCD (Intensified Customer Concern Definition) and TGW (Things Going Wrong), the content was developed in three main directions towards Customer Satisfaction, I) Characterize the vehicle as a high performance car, a pure sport car with outstanding performance for power train, suspensions and brakes mainly.
Technical Paper

Flow-Acoustic Coupling in Quarter-Wave Resonators Using Computational Fluid Dynamics

2001-04-30
2001-01-1430
Quarter-wave resonators are commonly used as acoustic silencers in automotive air induction systems. Similar closed side branches can also be formed in the idle air bypass, exhaust gas recirculation, and positive crankcase ventilation systems of engines. The presence of a mean flow across these side branches can lead to an interaction between the mean flow and the acoustic resonances of the side branch. At discrete flow conditions, this coupling between the flow and acoustic fields may produce high amplitude acoustic pressure pulsations. For the quarter-wave resonator, this interaction can turn the silencer into a noise generator, while for systems where a valve is located at the closed end of the side branch the large pressure pulsations can cause the valve to fail. This phenomenon is not limited to automotive applications, and also occurs in natural gas pipelines, aircraft, and numerous other internal and external flows.
Technical Paper

Wavelet-Based Visualization of Impulsive and Transient Sounds in Stationary Background Noise

2001-04-30
2001-01-1475
Scalograms based on shift-invariant orthonormal wavelet transforms can be used to analyze impulsive and transient sounds in the presence of more stationary sound backgrounds, such as wind noise or drivetrain noise. The visual threshold of detection for impulsive features on the scalogram (signal energy content vs. time and frequency,) is shown to be similar to the audible threshold of detection of the human auditory system for the corresponding impulsive sounds. Two examples of impulsive sounds in a realistic automotive sound background are presented: automotive interior rattle in a vehicle passenger compartment, and spark knock recorded in an engine compartment.
Technical Paper

Integrated, Feed-Forward Hybrid Electric Vehicle Simulation in SIMULINK and its Use for Power Management Studies

2001-03-05
2001-01-1334
A hybrid electric vehicle simulation tool (HE-VESIM) has been developed at the Automotive Research Center of the University of Michigan to study the fuel economy potential of hybrid military/civilian trucks. In this paper, the fundamental architecture of the feed-forward parallel hybrid-electric vehicle system is described, together with dynamic equations and basic features of sub-system modules. Two vehicle-level power management control algorithms are assessed, a rule-based algorithm, which mainly explores engine efficiency in an intuitive manner, and a dynamic-programming optimization algorithm. Simulation results over the urban driving cycle demonstrate the potential of the selected hybrid system to significantly improve vehicle fuel economy, the improvement being greater when the dynamic-programming power management algorithm is applied.
Technical Paper

The Prospects of Using Alcohol-Based Fuels in Stratified-Charge Spark-Ignition Engines

2007-10-29
2007-01-4034
Near-term energy policy for ground transportation is likely to have a strong focus on both gains in efficiency as well as the use of alternate fuels; as both can reduce crude oil dependence and carbon loading on the environment. Stratified-charge spark-ignition direct-injection (SIDI) engines are capable of achieving significant gains in efficiency. In addition, these engines are likely to be run on alternative fuels. Specifically, lower alcohols such as ethanol and iso-butanol, which can be produced from renewable sources. SIDI engines, particularly the spray-guided variant, tend to be very sensitive to mixture preparation since fuel injection and ignition occur within a short time of each other. This close spacing is necessary to form a flammable mixture near the spark plug while maintaining an overall lean state in the combustion chamber. As a result, the physical properties of the fuel have a large effect on this process.
Technical Paper

Engineering the Ford H2 IC Engine Powered E-450 Shuttle Bus

2007-10-29
2007-01-4095
As a part of a continuous research and innovation effort, Ford Motor Company has been evaluating hydrogen since 1997 as an alternative fuel option for vehicles with internal combustion engines. Hydrogen fuel is attractive in that it is the cleanest fuel. Hydrogen, when used in an internal combustion engine, produces an exhaust emission consisting mainly of water vapor, with no carbon dioxide and trace amounts of other regulated pollutants. Hydrogen can be produced from renewable sources which will help reduce the dependence on foreign oil. The implementation of the hydrogen powered IC engine is seen as a strategy to help transition from a petroleum economy to a hydrogen economy and drive development of hydrogen storage, fueling infrastructure and other hydrogen related technologies.
Technical Paper

The Effect of Oil Drain Interval on Valvetrain Friction and Wear

2007-10-29
2007-01-4133
Engine oils are subjected to a series of industry standard engine dynamometer tests to measure their wear protection capability, sludge and varnish formation tendencies, and fuel efficiency among several other performance attributes before they are approved for use in customer engines. However, these performance attributes are measured at the end of tests and therefore, do not provide any information on how the properties have changed during the tests. In one of our previous studies it was observed that engine oil samples collected from fleet vehicles after 12,000 mile drain interval showed 10-15 % lower friction and more importantly, an order of magnitude lower wear rate than those of fresh oils. It was also observed that the composition of the tribochemical films formed was quite different on the surface tested with the drain oils from those formed with fresh oils.
Technical Paper

General Motors Hydra-Matic & Ford New FWD Six-Speed Automatic Transmission Family

2007-04-16
2007-01-1095
The Hydra-Matic 6T70 is General Motors first model of a new, two-variant front wheel drive (FWD) six speed automatic transmission family. The second variant is a higher capacity model, the 6T75. The transmission was co-developed with Ford Motor Company. The 6F50 is the Ford variant that aligns with the GM 6T70 transmission. Approximately eighty five percent of the hardware is shared or common between the GM and Ford transmission variants. Ford will also have a higher capacity variant the 6F55 to align with the GM 6T75. The first GM application is the Saturn Aura for the 2007 Model Year. The Ford Edge and Lincoln MKX in MY 2007 will be the first applications for the 6F50. While the Hydra-Matic and Ford FWD six-speed family was designed with two variants in mind, the designed in modularity requires only changes to the second and third axis and case housings depending on specific torque requirements. This modular design enables a tremendous amount of part sharing.
Technical Paper

Fuel Economy Improvement Through Frictional Loss Reduction in Light Duty Truck Rear Axle

2002-10-21
2002-01-2821
In an effort to improve fuel economy for light duty trucks, an initiative was undertaken to reduce frictional losses in rear axle through use of low friction lubricants and novel surface finish on gears while maintaining durability. This paper describes the effect of rear axle lubricants on fuel economy. A laboratory rig was set up using a full size pick-up truck rear axle to measure axle efficiency and lubricant temperature with various SAE 75W-90 and SAE 75W-140 viscosity grade lubricants. Traction coefficients of lubricants were also measured at various temperatures using a laboratory ball and disk contact geometry. An improvement in axle efficiency up to 4.3% was observed over current Ford factory fill SAE 75W-140 lubricant depending on speed, torque and the type of lubricant used. The temperature of the lubricants was also lower than that with the current factory fill. This is important for maintaining bearing life and overall durability of the rear axle.
Technical Paper

Thermal Analysis of Cooling System in Hybrid Electric Vehicles

2002-03-04
2002-01-0710
Increased cooling demands in Hybrid Electric Vehicles (HEVs), compactness of engine compartment, and the additional hardware under the hood make it challenging to provide an effective cooling system that has least impact on fuel economy, cabin comfort and cost. Typically HEVs tend to have a dedicated cooling system for the hybrid components due to the different coolant temperatures and coolant flow rates. The additional cooling system doubles the hardware, maintenance, cost, weight and affects vehicle fuel economy. In addition to the cooling hardware, there are several harnesses and electronics that need air cooling under the hood. This additional hardware causes airflow restriction affecting the convective heat transfer under the hood. It also affects the radiation heat transfer due to the proximity of hardware close to the major heat sources like the exhaust pipe.
Technical Paper

Increasing Torque Output from a Turbodiesel with Camless Valvetrain

2002-03-04
2002-01-1108
In recent years sales of diesel-powered cars and trucks have increased dramatically worldwide. The efforts to raise specific power of diesel engines to allow for smaller and more efficient powertrains should include variable valvetrain technology. Some benefits that might become available with application of camshaft-based variable-valve mechanisms have been studied in [1]. Significant progress has also been reported in the development of camless actuation mechanisms [2, 3]. To fully evaluate the torque improvement opportunities for light duty diesel, the authors have assumed that a camless valvetrain will become available in the future. This will provide the ultimate flexibility to choose timing and duration of valve events to maximize full load torque. Simulation results revealed potential for a substantial increase in engine torque by optimizing the intake and exhaust valve timing together with turbocharger operation.
Technical Paper

Dynamometer Development Results for a Stratified-Charge DISI Combustion System

2002-10-21
2002-01-2657
This report describes the dynamometer testing portion of the combustion system development of a direct-injection stratified-charge gasoline engine. The engine used in this study is a single-cylinder, direct-injection engine with a newly designed cylinder head comprised of 4-valves per cylinder, an intake-side-mounted DI fuel injector and a bowl-in-piston wall-guided stratified-charge combustion system. Test results detailed in this report include evaluation of four piston designs, two combustion chamber designs, and two injector spray angles. Tests were run at stratified-charge part-load, homogeneous-charge part-load, and WOT conditions. The program had aggressive goals in improving both WOT performance and part-load fuel economy while achieving Stage IV emission requirements. Tests results showed that the engine was able to meet these program goals.
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