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Carbon, hydrogen and oxygen are major elements in vehicle fuels. Knowledge of fuels elemental composition is helpful in addressing its performance characteristics. Carbon, hydrogen and oxygen composition is an important parameter in engine calibration affecting vehicle performance, emissions and fuel economy. Biodiesel, a fuel comprised of mono-alkyl esters of long-chain fatty acids also known as Fatty Acid Methyl Esters(FAME), derived from vegetable oils or animal fats, has become an important commercial marketplace automotive fuel in the United States (US) and around the world over last few years. FAME biodiesels have many chemical and physical property differences compared to conventional petroleum based diesel fuels. Also, the properties of biodiesel vary based on the feedstock chosen for biodiesel production. One of the key differences between petroleum diesel fuels and biodiesel is the oxygen content.

The Austempering heat treatment is a well-known solution to improve the mechanical properties of ductile cast irons, therefore being referred as 'ADI' (Austempered Ductile Iron). The improved mechanical properties of ADI's with respect to conventional ductile iron is attributed to its resulting microstructure, which contains mainly carbide-free bainite with stabilized retained austenite. More recently, ductile cast irons were submitted to another heat treatment, known as 'Quenching and Partitioning' (Q&P). In this case, the ductile cast iron is austenitized, quenched to a temperature between Mf and Ms temperatures and subsequently heated to a temperature above Ms in order to partition the carbon from the martensite to the remaining austenite. The resulting microstructure comprises mainly low carbon martensite, austenite (stabilized by the carbon partition) and carbide-free bainite. Such microstructure resulted in equal or better properties than ADI.

The objective of this paper is to propose a new model in the identification of a contributing factor to the generation of Radio Frequency Interference (RFI) due to the operation of a spark-ignited engine. This model incorporates parameters in the electrical operation of the ignition system components and their interaction with the engine mechanical structure, which is also used as a circuit component (the ignition system “ground”). T he model was developed as a result of analysis of numerous studies that have been conducted over the years in an attempt to identify why RFI characteristics can differ when using identical components on different engines, or locating the components in different locations on identical engines. This situation is a problem due to the resulting uncertainty with respect to the determination of what is the optimum vehicle ignition system configuration to meet all electrical and RFI or electromagnetic compatibility (EMC) requirements.

The paper examines how the issue of lengthy development times can be mitigated by adopting a multivariable physics based control method for the development and deployment of complex engine control algorithms required for modern diesel engines equipped with Lean NOx Trap aftertreatment technology. The proposed approach facilitates manufacturers to consider lower cost powertrain configurations for selected markets while maintaining higher performance configurations for other markets. The contribution includes on-engine results from joint work between General Motors and Honeywell. The Honeywell OnRAMP Design Suite which applies model predictive control techniques was used for model identification, control design (using model predictive control) and its calibration. With no prior work on the engine this process of calibrating an engine model and achieving transient drive cycle control on the engine required ten days in the test cell and five days of offline work using the OnRAMP software.

Powerful vehicles that are adequately designed to corner at high speeds can generate very high lateral forces at tire-road interface. These forces are counter balanced by chassis, suspension and brake components allowing the vehicle to confidently maneuver around a corner. Although these components may not damage under such high cornering loads, elastic deflections can significantly alter a vehicles performance. One such phenomenon is increased brake pedal travel, to engage brakes, after severe cornering maneuvers. Authors of this paper have worked together to solve exactly this problem on a very powerful luxury segment car.

Limited-slip differentials improve traction and handling when compared to open differentials, but offer no active modulation and can compromise typical driving. A number of passive control systems exist that attempt to reduce this compromise. Electronically controlled limited-slip differentials (eLSD) are being introduced that allow active control of the differential in all driving situations and can be operated as an open differential, a fully locked differential, or at any point between these extremes. Such an eLSD system was implemented in two General Motors front wheel drive cars-one on an automatic transmission and applied by the transmission pump, the other on a manual transmission and applied by an external pump. This eLSD system contains a multi-plate wet clutch connected to the differential carrier and right side half-shaft of an all wheel drive capable transmission.

A Soot-NOx Trap (SNT) is a combinatorial aftertreatment device intended to decrease both particulate and NOx emissions simultaneously. A system-level Soot-NOx Trap model was developed by adding Lean NOx Trap kinetics to a 1D Diesel Particulate Filter model. The hybrid model was validated against each parent model for the limiting cases, then exercised to investigate the interacting redox behavior. Modulations in temperature and exhaust air-fuel ratio were investigated for their ability to facilitate particulate oxidation and NOx reduction in the trap.

The automotive industry has long relied on vehicle testing to evaluate drive train components for new vehicle applications. In the past it has been impossible to fully evaluate components such as transmissions in a laboratory environment using electric motors as prime movers and absorbers. Although some durability and performance testing can be accomplished on such test stands it is impossible to perform high fidelity controller calibrations, durability tests, and NVH evaluations. Since the electric motors on these test stands cannot duplicate the exact characteristics of an engine such as inertia and firing pulses many manufacturers have resorted to vehicle testing or engine driven testing. Vehicle and engine based tests have many downfalls that could be avoided through the use of a laboratory based test system with electric prime movers. Vehicle testing with human drivers is often subjectively controlled and the exact test conditions are often unrepeatable.

The new General Motors 2-Mode Hybrid transmission for full-size, full-utility SUVs integrates two electro-mechanical power-split operating modes with four fixed gear ratios and provides fuel savings from electric assist, regenerative braking and low-speed electric vehicle operation. A combination of two power-split modes reduces the amount of mechanical power that must be converted to electricity for continuously variable transmission operation. Four fixed gear ratios further improve power transmission capacity and efficiency for especially demanding maneuvers such as full acceleration, hill climbing, and towing. This paper explains the basics of electro-mechanical power-split transmissions, input-split and compound-split modes, and the addition of fixed gear ratios to these modes to create the 2-Mode Hybrid transmission for SUVs.

Electrically variable transmissions divide power between the electrical and mechanical paths using input, output, or compound split schemes. When combined with an electrical energy storage element such as a battery, these systems allow numerous fuel saving and performance benefits. This paper examines the design tradeoffs in each of the three topologies in order to balance fuel economy, system performance against requirements, and electrical component size. A general EVT analysis method is presented and used to study the fuel economy and performance sensitivity of the three configurations to motor, inverter, and battery constraints, and planetary gear ratios. To evaluate fuel economy, the three systems are assessed for each of the primary fuel economy mechanisms enabled by hybridization. To evaluate performance tradeoffs, system performance against typical vehicle performance design points is compared.

Recent advancements in simulation software and computational hardware make it realizable to simulate a full vehicle system comprised of multiple sub-models developed in different modeling languages. The so-called, co-simulation allows one to develop a control strategy and evaluate various aspects of a vehicle system, such as fuel efficiency and vehicle drivability, in a cost-effective manner. In order to study the feasibility of the synchronized parallel processing in co-simulation this paper presents two co-simulation frameworks for a complete vehicle system with multiple heterogeneous subsystem models. In the first approach, subsystem models are co-simulated in a serial configuration, and the same sub-models are co-simulated in a parallel configuration in the second approach.

The objective of the paper is to outline a CFD based lumped parameter method that compares the thermal performance of brake rotors, predicts the transient temperatures and brake lining wear in vehicle. A two-pronged approach was developed for this purpose. A rotor stand-alone model was used to predict rotor performance curves. Simultaneously heat transfer coefficients of the brake rotor were computed corresponding to the rotor performance curves and the appropriate heat transfer correlations were established. The second part of this approach involved developing a brake model in a vehicle and solving for the air flow through rotors in different vehicles at various speeds. These rotor flows were cross-referenced with the rotor performance curves, generated earlier for that rotor, to compute the heat transfer coefficients in the vehicle.

The friction material is arguably at the heart of any brake system, with its properties taking one of the most important roles in defining its performance characteristics. High performance applications, such as race track capable brake systems in high powered vehicles, exert considerable stress on the friction materials, in the form of very high heat flux loads, high clamp and brake torque loads, and high operating temperatures. It is important, for high performance applications, to select capable friction materials, and furthermore, it is important to understand fully what operating conditions the friction material will face in the considered application.

Vehicle dynamics simulation with Hardware In the Loop (HIL) has been demonstrated to reduce development and validation time for dynamic control systems. For dynamic control systems such as Anti-lock Braking System (ABS) and Electronic Stability Control (ESC), an accurate vehicle dynamics performance simulation system requires the Electronic Brake Control Module (EBCM) coupled with the vehicles brake system hardware. This kind of HIL simulation-specific software tool can further increase efficiency by means of automation and optimization of the development and validation process. This paper presents a method for HIL vehicle dynamics simulator optimization through Brake Response Time (BRT) correlation. The paper discusses the differences between the physical vehicle and the HIL vehicle dynamics simulator. The differences between the physical and virtual systems are used as factors in the development of a Design Of Experiment (DOE) quantifying HIL simulator performance.

Manual transmissions for passenger cars are facing pressures due to rapid growth of automatic transmissions, which already represents more than 60% of Brazil market, and from higher torque demand due to strict emission legislation, which turbo engines had presented great contribution to it. To solve this contradictory issue, gears with higher strength and lower cost have been studied to replacement Nickel by Niobium in the steels. Furthermore, this technology could be applied to solve the issues with electrified vehicle, where high torque, speed and lifetime are demanded pursued for gears. This study aimed to build prototypes and compare the S-N curves, fracture analysis, microstructure for three kinds of steels (QS4321 with Ni, QS1916 FG without Ni & with Nb and QS 1916 without Ni and Nb) in the condition carburized, hardened and tempered with and without shot peening.

Economic market forces and increasing environmental awareness of gasoline have led to interest in developing alternatives to gasoline, and extending the current global supply for transportation fuels. One viable strategy is the use of alternative alcohol fuels for combustion engines, with ethanol and methanol in various concentration ranges proposed and in-use. Utilizing and citing data from this review, a comprehensive overview of the materials selection and engineering challenges facing metals, plastics and elastomers are presented. The engineering approach and solution-sets discussed will focus on production feasibility and implementation. The effects from the fuel chemistry and quality of fuel ethanol produced on the related vehicle components are discussed.

Internal combustion engines (ICEs) exhaust emissions, particularly nitrogen oxides (NOx), have become a growing environmental and health concern. The biggest challenge for contemporary ICE industry is the development of clean ICEs, and the use of advanced design tools like Computational Fluid Dynamics (CFD) simulation is paramount to achieve this goal. In particular, the development of aftertreatment systems like Selective Catalyst Reduction (SCR) is a key step to reduce NOx emissions, and accurate and efficient CFD models are essential for its design and optimization. In this work, we propose a novel 3D-CFD methodology, which uses a Machine Learning (ML) approach as a surrogate model for the SCR catalyst chemistry, which aims to enhance accuracy of the simulations with a moderate computational cost. The ML approach is trained on a dataset generated from a set of 1D-CFD simulations of a single channel of an SCR catalyst.

The increasing demand for energy savings in cars of high production volume, especially those classified as emerging market vehicles, has led the automotive industry to focus on several strategies to achieve higher efficiency levels from their systems and components. One of the most diffuse initiatives is reducing weight through the application of the so-called light alloys. An engine cylinder block can contribute nearly two percent of the vehicle's total mass. Special attention and soon repercussion are given when someone decides to apply a light alloy such as the aluminum to this component. Nonetheless, it is known that peculiarities in terms of physical, chemical and mechanical properties, due to the material nature, associated with regional market characteristics make the initial feasibility analysis study definitely one of the most important stages for the material choice decision.

In the North American automotive market, cylinder deactivation by means of engine valve deactivation is becoming a significant enabler in reducing the Brake Specific Fuel Consumption (BSFC) of large displacement engines. This allows for the continued market competitiveness of large displacement spark ignition (SI) engines that provide exceptional performance with reduced fuel consumption. As an alternative to a major engine redesign, the Active Fuel Management™ (AFM™) system is a lower cost and effective technology that provides improved fuel economy during part-load conditions. Cylinder deactivation is made possible by utilizing innovative new base engine hardware in conjunction with an advanced control system. In the GM 3.9L V-6 Over Head Valve (OHV) engine, the standard hydraulic roller lifters on the engine's right bank are replaced with deactivating hydraulic roller lifters and a manifold assembly of oil control solenoids.

The present work aims to characterize the microstructure of valvetrain camshaft lobes that are currently applied in the automotive industry, obtained by different processing routes. The cam lobe microstructure has been assessed by microscopy, whereas the mechanical properties by hardness profile measurements on the surface region. Microconstituents type and form, composing the final microstructure at the cam lobe work region, are defined by the casting route and/or post-heat treatment process other than alloy chemical composition, so that knowledge and control of processing route is vital to assure suitable valvetrain system assembly performance and durability. Most of the mechanical solicitations on the part occur at the interface between cam and follower; the actual contact area is significantly smaller than the apparent area. As a result, the microstructure at and near the surface performs a direct role on the performance of the valvetrain, cam lobe and its counterpart.