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Technical Paper

Year-Long Evaluation of Trucks and Buses Equipped with Passive Diesel Particulate Filters

2002-03-04
2002-01-0433
A program has been completed to evaluate ultra-low sulfur diesel fuels and passive diesel particulate filters (DPFs) in truck and bus fleets operating in southern California. The fuels, ECD and ECD-1, are produced by ARCO (a BP Company) and have less than 15 ppm sulfur content. Vehicles were retrofitted with two types of catalyzed DPFs, and operated on ultra-low sulfur diesel fuel for over one year. Exhaust emissions, fuel economy and operating cost data were collected for the test vehicles, and compared with baseline control vehicles. Regulated emissions are presented from two rounds of tests. The first round emissions tests were conducted shortly after the vehicles were retrofitted with the DPFs. The second round emissions tests were conducted following approximately one year of operation. Several of the vehicles retrofitted with DPFs accumulated well over 100,000 miles of operation between test rounds.
Technical Paper

World Wide Escort/Lynx Engine Design and Development

1981-02-01
810008
In 1981, Ford Motor Company introduced a new family of fuel efficient four cylinder engines world wide. These engines, based on a compound valve arrangement in a hemispherical combustion chamber, were specifically designed for installation in light weight front-wheel-drive vehicles. Ford Research efforts were integrated with the resources of Ford U.S. and Ford of Europe to design and develop the engine in a compressed time frame. The technical and organizational efforts to accomplish this task, as well as, the design and development are discussed.
Technical Paper

Wave Propagation in Catalytic Converters: A Preliminary Investigation

1997-05-20
971873
The present study investigates the wave propagation and attenuation in catalytic converters. The relationships for wave propagation in a catalytic monolith are derived first and then coupled to the wave propagation in tapered ducts. Analytical predictions are compared with experimental results to validate the theory.
Technical Paper

WHERE DOES ALL THE POWER GO?

1957-01-01
570058
AS a basis for the analyses of this symposium, a hypothetical car has been used to evaluate the engine power distribution in performance. Effects of fuel,-engine accessories, and certain car accessories are evaluated. The role of the transmission in making engine power useful at normal car speeds is also discussed. Variables encountered in wind and rolling resistance determinations are reevaluated by improved test techniques. Net horsepower of the car in terms of acceleration, passing ability and grade capability are also summarized.
Technical Paper

Virtual Engine Dynamometer in Service Life Testing of Transmissions: A Comparison Between Real Engine and Electric Dynamometers as Prime Movers in Validation Test Rigs

2010-04-12
2010-01-0919
A test cell was developed for evaluating a 6-speed automatic transmission. The target vehicle had an internal combustion 5.4L gasoline V8 engine. An electric dynamometer was used to closely simulate the engine characteristics. This included generating mean torque from the ECU engine map, with a transient capability of 10,000 rpm/second. Engine inertia was simulated with a transient capability of 20,000 rpm/second, and torque pulsation was simulated individually for each piston, with a transient capability of 50,000 rpm/second. Quantitative results are presented for the correlation between the engine driven and the dynamometer driven transmission performance over more than 60 test cycles. Concerns about using the virtual engine in validation testing are discussed, and related to the high frequency transient performance required from the electric dynamometer. Qualitative differences between the fueled engine and electric driven testing are presented.
Technical Paper

Vehicle System Control for Start-Stop Powertrains with Automatic Transmissions

2013-04-08
2013-01-0347
The 2013 Ford Fusion will be launched with an optional automatic engine start-stop feature. To realize engine start-stop on a vehicle equipped with a conventional powertrain, there are two major challenges in the vehicle system controls. First, the propulsive torque delivery from a stopped engine has to be fast. The vehicle launch delay has to be minimized such that the corporate vehicle attributes can be met. Second, the fuel economy improvement offered by this technology has to justify the cost associated with it. In pursuing fuel economy, the driver's comfort and convenience should be minimally impacted. To tackle these challenges, a vehicle system control strategy has been developed to accurately interpret the driver's intent, monitor the vehicle subsystem's power demands, schedule engine automatic stop and re-start, and coordinate the fast and smooth torque delivery to the wheels.
Technical Paper

Vehicle Response to Throttle Tip-In/Tip-Out

1985-05-15
850967
Throttle tip-in/tip-out maneuvers generate a driveline torque transient which may produce an objectionable disturbance to vehicle occupants. Recent developments in vehicle design have contributed to increased severity in this response, which is known as clunk and shuffle. This paper describes experimental procedures which have been developed to quantify response levels and diagnose cases of concern. These techniques are useful for developing engine control systems which require transient strategies that differ greatly from those required for steady state operation. In addition, specific design and calibration modifications, which control clunk and shuffle, are described.
Technical Paper

Vehicle Exhaust Particle Size Distributions: A Comparison of Tailpipe and Dilution Tunnel Measurements

1999-05-03
1999-01-1461
This paper explores the extent to which standard dilution tunnel measurements of motor vehicle exhaust particulate matter modify particle number and size. Steady state size distributions made directly at the tailpipe, using an ejector pump, are compared to dilution tunnel measurements for three configurations of transfer hose used to transport exhaust from the vehicle tailpipe to the dilution tunnel. For gasoline vehicles run at a steady 50 - 70 mph, ejector pump and dilution tunnel measurements give consistent results of particle size and number when using an uninsulated stainless steel transfer hose. Both methods show particles in the 10 - 100 nm range at tailpipe concentrations of the order of 104 particles/cm3.
Technical Paper

Variable Displacement by Engine Valve Control

1978-02-01
780145
Intake and exhaust valve control has been combined with engine calibration control by an on-board computer to achieve a Variable Displacement Engine with improved BSFC during part throttle operation. The advent of the on-board computer, with its ability to provide integrated algorithms for the fast accurate flexible control of the entire powertrain, has allowed practical application of the valve disabler mechanism. The engine calibration basis and the displacement selection criteria are discussed, as are the fuel economy, emissions and behavior of a research vehicle on selected drive cycles ( Metro, Highway and Steady State ). Additionally, the impact upon vehicle driveability and other related subsystems ( e.g., transmission ) is addressed.
Technical Paper

Using Experimental Modal Modeling Techniques to Investigate Steering Column Vibration and Idle Shake of a Passenger Car

1985-05-15
850996
An experimental modal model of an early prototype car was constructed and validated against test results. The model was then used to suggest practical hardware modification alternatives which would: (1) shift the steering column resonant frequency away from the idle range, and (2) maintain a low steering column tip vibration within the 600-750 RPM idle range. This model was also used to evaluate the effectiveness of tuning radiator mounts to the overall vehicle idle quality. It was found that a pair of braces from either the steering column bracket to brake pedal bracket or to the cowl top area could improve idle shake of the test vehicle. The driver side brake pedal brace alone is not effective. However, the passenger side brake pedal brace alone is as effective as the two brake pedal braces together. It was found that the radiator mounts on the test vehicle are extremely non-linear. Therefore, tuning the mount to improve idle quality is impractical.
Technical Paper

Understanding the Thermodynamics of Direct Injection Spark Ignition (DISI) Combustion Systems: An Analytical and Experimental Investigation

1996-10-01
962018
Direct-injection spark-ignition (DISI) engines have been investigated for many years but only recently have shown promise as a next generation gasoline engine technology. Much of this new enthusiasm is due to advances in the fuel injection system, which is now capable of producing a well-controlled spray with small droplets. A physical understanding of new combustion systems utilizing this technology is just beginning to occur. This analytical and experimental investigation with a research single-cylinder combustion system shows the benefits of in-cylinder gasoline injection versus injection of fuel into the intake port. Charge cooling with direct injection is shown to improve volumetric efficiency and reduce the mixture temperature at the time of ignition allowing operation with a higher compression ratio which improves the thermodynamic cycle efficiency.
Technical Paper

Underhood Thermal Management by Controlling Air Flow

1995-02-01
951013
A series of tests were conducted to determine the potential for reducing vehicle underhood temperatures by either 1) diverting the radiator fan air flow from the engine compartment or 2) by forced air cooling of the exhaust manifold in conjunction with shielding it or 3) by a combination of the two methods. The test vehicle was a Ford F-250 Light Truck with a 7.5L V-8 engine. The vehicle was tested in a dynamometer cell equipped with cell blowers to simulate road speed conditions. It was found that diverting the outlet air from the radiator will reduce underhood component temperatures when the vehicle is in motion and also at normal idle. However, if the vehicle is to be used for power takeoff applications requiring a “kicked” idle, then forced cooling of the exhaust manifolds is also required to maintain reduced underhood temperatures. A combination of these two techniques maximized the reduction of underhood temperatures for all operating conditions tested.
Technical Paper

US 2010 Emissions Capable Camless Heavy-Duty On-Highway Natural Gas Engine

2007-07-23
2007-01-1930
The goal of this project was to demonstrate a low emissions, high efficiency heavy-duty on-highway natural gas engine. The emissions targets for this project are to demonstrate US 2010 emissions standards on the 13-mode steady state test. To meet this goal, a chemically correct combustion (stoichiometric) natural gas engine with exhaust gas recirculation (EGR) and a three way catalyst (TWC) was developed. In addition, a Sturman Industries, Inc. camless Hydraulic Valve Actuation (HVA) system was used to improve efficiency. A Volvo 11 liter diesel engine was converted to operate as a stoichiometric natural gas engine. Operating a natural gas engine with stoichiometric combustion allows for the effective use of a TWC, which can simultaneously oxidize hydrocarbons and carbon monoxide and reduce NOx. High conversion efficiencies are possible through proper control of air-fuel ratio.
Journal Article

Turbocharger Turbine Inlet Isentropic Pressure Observer Model

2015-04-14
2015-01-1617
Exhaust pressures (P3) are hard parameters to measure and can be readily estimated, the cost of the sensors and the temperature in the exhaust system makes the implementation of an exhaust pressure sensor in a vehicle control system a costly endeavor. The contention with measured P3 is the accuracy required for proper engine and vehicle control can sometimes exceed the accuracy specification of market available sensors and existing models. A turbine inlet exhaust pressure observer model based on isentropic expansion and heat transfer across a turbocharger turbine was developed and investigated in this paper. The model uses 4 main components; an open loop P3 orifice flow model, a model of isentropic expansion across the turbine, a turbine and pipe heat transfer models and an integrator with the deviation in the downstream turbine outlet parameter.
Journal Article

Transient Build-up and Effectiveness of Diesel Exhaust Gas Recirculation

2014-04-01
2014-01-1092
Modern diesel engines employ a multitude of strategies for oxides of nitrogen (NOx) emission abatement, with exhaust gas recirculation (EGR) being one of the most effective technique. The need for a precise control on the intake charge dilution (as a result of EGR) is paramount since small fluctuations in the intake charge dilution at high EGR rates may cause larger than acceptable spikes in NOx/soot emissions or deterioration in the combustion efficiency, especially at low to mid-engine loads. The control problem becomes more pronounced during transient engine operation; currently the trend is to momentarily close the EGR valve during tip-in or tip-out events. Therefore, there is a need to understand the transient EGR behaviour and its impact on the intake charge development especially under unstable combustion regimes such as low temperature combustion.
Technical Paper

Transient A/F Estimation and Control Using a Neural Network

1997-02-24
970619
A new estimator for IC engine A/F ratio is described. A/F ratio is important for engine operation since it determines the quantities of engine emissions, such as HC, CO, NOx, the conversion efficiency of catalyst systems, and the engine combustion stability. The A/F ratio estimator described in this paper is based on a fundamental metric that relies on inducing and detecting crankshaft speed fluctuations caused by modulating the engine's fuel injection pulse widths. Fuel pulse width modulation varies the instantaneous combustion A/F ratio crankshaft velocity. Synchronous measurement of crankshaft velocity provides a metric that, when used with other engine state variables as inputs to a conventional neural network, can accurately estimate A/F ratio. The estimator provides A/F information when a physical sensor is not available.
Technical Paper

Traction Behavior Under Extreme Conditions

1999-10-25
1999-01-3612
Traction drive continuously variable transmissions (TCVTs) are under active investigation by a number of OEMs and suppliers. Along with advances in control systems and metallurgy, improved traction fluids will be key to successful implementation of this technology. Traction fluids will need to function over a wide range of temperatures and contact pressures. Contact pressures may reach as high as 4 GPa, while temperatures may range from about - 40 C to about 140 C. It is widely recognized that low temperature fluidity at start-up is an issue, since fluids which give high traction coefficients and adequate viscosity under normal operating temperatures generally exhibit high viscosity at low temperatures. However, fe published data are available on traction behavior at temperatures below about 20 C and at contact pressures above about 2 GPa.
Technical Paper

Total Thermal Management of Battery Electric Vehicles (BEVs)

2018-05-30
2018-37-0026
The key hurdles to achieving wide consumer acceptance of battery electric vehicles (BEVs) are weather-dependent drive range, higher cost, and limited battery life. These translate into a strong need to reduce a significant energy drain and resulting drive range loss due to auxiliary electrical loads the predominant of which is the cabin thermal management load. Studies have shown that thermal sub-system loads can reduce the drive range by as much as 45% under ambient temperatures below −10 °C. Often, cabin heating relies purely on positive temperature coefficient (PTC) resistive heating, contributing to a significant range loss. Reducing this range loss may improve consumer acceptance of BEVs. The authors present a unified thermal management system (UTEMPRA) that satisfies diverse thermal and design needs of the auxiliary loads in BEVs.
Technical Paper

Torsional Response of Automotive Timing Chain Systems

1994-03-01
940689
An analytical model is developed to describe the longitudinal response of the timing chain and the associated torsional response of all the sprockets and tensioner. A closed form equilibrium analysis reveals that equilibrium tensions are functions of tensioner stiffness, chain preload, steady cam torques and engine speed. The equations of motion are linearized about the equilibrium position to determine natural frequencies, mode shapes of the torsional modes and the forced response due to cam torque harmonics. Experimental measurements of the system natural frequencies and the forced amplitudes are in good agreement with the theoretical predictions.
Technical Paper

Time-Resolved Measurement of Speciated Hydrocarbon Emissions During Cold Start of a Spark-Ignited Engine

1994-03-01
940963
Speciated HC emissions from the exhaust system of a production engine without an active catalyst have been obtained with 3 sec time resolution during a 70°F cold start using two control strategies. For the conventional cold start, the emissions were initially enriched in light fuel alkanes and depleted in heavy aromatic species. The light alkanes fell rapidly while the lower vapor pressure aromatics increased over a period of 50 sec. These results indicate early retention of low vapor pressure fuel components in the intake manifold and exhaust system. Loss of higher molecular weight HC species does occur in the exhaust system as shown by experiments in which the exhaust system was preheated to 100° C. The atmospheric reactivity of the exhaust HC emissions for photochemical smog formation increases as the engine warms.
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