Search Results

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.

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.

Several emission performance tests like Butane Working Capacity (BWC), Cycle Life, and ORVR load tests are required for the certification of a vehicle; these tests are both expensive and time consuming. This paper presents a test process based upon analytical simulation of BWC of an automotive carbon canister in order to greatly reduce the cost incurred in physical tests. The computational model for the fixed-bed system of a carbon canister is based upon non-equilibrium, non-Isothermal, and non-adiabatic algorithm to simulate the real life loading/purging of hydrocarbon vapors from this device.

This paper presents the extended Kalman filter-based sideslip angle estimator design using a nonlinear 5DoF single-track vehicle dynamics model with stochastic modeling of tire forces. Lumped front and rear tire forces have been modeled as first-order random walk state variables. The proposed estimator is primarily designed for vehicle sideslip angle estimation; however it can also be used for estimation of tire forces and cornering stiffness. This estimator design does not rely on linearization of the tire force characteristics, it is robust against the variations of the tire parameters, and does not require the information on coefficient of friction. The estimator performance has been first analyzed by means of computer simulations using the 10DoF two-track vehicle dynamics model and underlying magic formula tire model, and then experimentally validated by using data sets recorded on a test vehicle.

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.

Minimizing fuel consumption is emerging as the next major challenge for engine control and calibration, even as the requirements of complying with ever lower transient emissions regulations cannot be underestimated. Meeting these difficult and apparently conflicting emissions and efficiency goals is becoming increasingly onerous as engine and aftertreatment control complexity increases. Conventional engine calibration techniques are by nature time-intensive, ad-hoc and repetitive, resulting in low productivity of test facilities and engineering effort. Steady state engine mapping methods, such as design of experiments, do little to ensure transient emissions compliance or fuel consumption optimization. A new model-based Rapid Transient Calibration system has been developed, tested and validated using a 2007 production-specification Detroit Diesel Series 60 heavy-duty diesel engine.

As evidenced by extensive research work done under contract to the government recently, it is clear that there is a strong federal interest in the limit handling performance of automobiles. Should these efforts come to fruition, manufacturers may be faced with the difficult task of designing vehicles to meet independent and, at times, conflicting handling requirements. Not only must vehicles continue to meet with subjective approval of handling behavior by customers, but they may also be required to meet objective limit performance criteria. Problems arise in that vehicles designed to achieve high levels of limit performance are not guaranteed to be more controllable or subjectively acceptable to customers. This paper shows ways design changes may cause conflicting influences on several measures of performance.

The feasibility of using experimentally determined flow fields at intake valve closing, IVC, as initial conditions for computing the in-cylinder flow dynamics during the compression stroke is demonstrated by means of a computer simulation of the overall approach. A commercial CFD code, STAR-CD, was used for this purpose. The study involved two steps. First, in order to establish a basis for comparison, the in-cylinder flow field throughout the intake and compression strokes, from intake valve opening, IVO, to top dead center, TDC, was computed for a simple engine geometry. Second, experimental initial conditions were simulated by randomly selecting and perturbing a set of velocity vectors from the computed flow field at IVC.

Suspension roll centers are currently used to establish vehicle handling characteristics such as under-steer and feel. Roll centers were developed to help understand vehicle designs on paper. Computers and mechanism simulation software allows vehicle models to be built and analyzed. Analyzing forces and moments may be a better technique as opposed to modeling suspension roll centers. A proposed method is to look directly at forces applied to the vehicle body and moments resulting from the applied forces. This force-moment method includes the effects of load transfer and tread change, which are not accounted for by geometric roll centers.

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.

Present models and methods for simulations of sheet metal forming processes are reviewed in this paper. Because of rapid progress of computer hardware, complex computations, formerly impossible to perform due to high computational cost, are now feasible. Therefore, more realistic and computational intensive models are suggested for finite elements, materials, and frictional forces. Also, simulation methods suitable for sheet metal forming processes are recommended. Four numerical examples at the end of the paper are presented to support the recommendations.

This paper identifies and analyzes steady-state and transient tire properties affecting vehicle directional response characteristics. The study is limited to the relationship between lateral force and slip angle. It shows fundamental differences between steady-state and transient properties. Tire transient properties are described by a force-slip angle loop with cornering stiffness and dynamic lateral force offset as parameters. Cornering stiffness is presented as a variable that changes with speed and steer rate. An interrelationship between cornering stiffness and dynamic lateral force offset resulting from the time lag between lateral force and slip angle is shown. Ramp steer techniques for measuring transient tire properties on a road trailer and on an external drum machine are described. A need for transient tire data for computer simulations of vehicle transient steer maneuvers is shown.

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.

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.

Thermophysical properties of materials used in the design of automotive interiors are needed for computer simulation of climate conditions inside the vehicle. These properties are required for assessment of the vehicle occupants' thermal sensation as they come in contact with the vehicle interior components, such as steering wheels, arm rests, instruments panel and seats. This paper presents the results of an investigation into the thermophysical properties of materials which are required for solving the non-linear Fourier equations with any boundary conditions and taking into account materials' specific heat, volume density, thermal conductivity, and thermal optical properties (spectral and total emissivity and absorptivity). The model and results of the computer simulation will be published in a separate paper.

In this study, the particle emission characteristics of 10% alternative diesel fuel blends (Rapeseed Methyl Ester and Gas-to-Liquid) were investigated through the tests carried out on a light duty common-rail Euro 4 diesel engine. Under steady engine conditions, the study focused on particle number concentration and size distribution, to comply with the particle metrics of the European Emission Regulations (Regulation NO 715/2007, amended by 692/2008 and 595/2009). The non-volatile particle characteristics during the engine warming up were also investigated. They indicated that without any modification to the engine, adding selected alternative fuels, even at a low percentage, can result in a noticeable reduction of the total particle numbers; however, the number of nucleation mode particles can increase in certain cases.

A new diesel engine, called the 6.7L Power Stroke® V-8 Turbocharged Diesel, and code named "Scorpion" has been designed and developed by Ford Motor Company for the full-size pickup truck and light commercial vehicle markets. It incorporates the latest design technology to meet 2010 model year emission regulations for both chassis and dynamometer-based certifications, and is compatible with up to B20 biodiesel fuel. The engine is an entirely new 90 degree V-8 design featuring inboard exhaust, piezo common rail fuel injection, a new dual compressor wheel turbocharger, and dual loop cooling systems. The 6.7L is Ford's first diesel engine designed for the North American pickup and light commercial truck market.

The current Brazilian tax legislation promotes vehicles, powered by engines with up to 1.0l displacement. In order to offer the customer an engine with the maximum tax advantage, a supercharged derivative of the Ford 1.0l Zetec RoCam engine was developed. The market specific boundary conditions in South America require powertrains with immediate response especially at low engine speeds. This can be achieved by a supercharged engine concept. The paper discusses the required engine modifications for the supercharger application. The combustion system was changed to benefit from the higher volumetric efficiency, including the optimisation of the intake, exhaust and bypass control system. Extensive modifications of the base engine were required to adapt the engine to the higher thermal load and the specific boundary condition of a supercharger application.

Gas carburized and quenched low alloy steels typically produce surface microstructures which contain martensite, retained austenite and often NMTP's (non-martensitic transformation products). The NMTP's are caused by a reduction of surface hardenability in the carburizing process from loss of alloying elements to oxidation. Gas carburized low alloy steels such as SAE 8620 with NMTP's on the surface have been shown to have inferior bending fatigue properties when compared to more highly alloyed steels which do not form NMTP's, such as SAE 4615M. One method of minimizing the formation of oxides and eliminating NMTP formation during carburizing and quenching is to use plasma carburizing instead of conventional gas carburizing. In this study the microstructures and bending fatigue performance of plasma carburized SAE 8620 and SAE 4615M is compared to the same alloys conventionally gas carburized and quenched.

A set of scaling laws were previously developed to guide the transfer of combustion system designs between diesel engines of different sizes [ 1 , 2 , 3 , 4 ]. The intent of these scaling laws was to maintain geometric similarity of key parameters influencing diesel combustion such as in-cylinder spray penetration and flame lift-off length. The current study explores the impact of design constraints or limitations on the application of the scaling laws and the effect this has on the ability to replicate combustion and emissions. Multi dimensional computational fluid dynamics (CFD) calculations were used to evaluate the relative impact of engine design parameters on engine performance under full load operating conditions. The base engine was first scaled using the scaling laws. Design constraints were then applied to assess how such constraints deviate from the established scaling laws and how these alter the effectiveness of the scaling effort.