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With increasingly stringent emissions regulations and concurrent requirements for enhanced engine thermal efficiency, a comprehensive characterization of the automotive gasoline fuel spray has become essential. The acquisition of accurate and repeatable spray data is even more critical when a combustion strategy such as gasoline direct injection is to be utilized. Without industry-wide standardization of testing procedures, large variablilities have been experienced in attempts to verify the claimed spray performance values for the Sauter mean diameter, Dv90, tip penetration and cone angle of many types of fuel sprays. A new SAE Recommended Practice document, J2715, has been developed by the SAE Gasoline Fuel Injection Standards Committee (GFISC) and is now available for the measurement and characterization of the fuel sprays from both gasoline direct injection and port fuel injection injectors.

The introduction of tumble into the combustion chamber is an effective method of enhancing turbulence intensity prior to ignition, thereby accelerating the burn rates, stabilizing the combustion, and extending the dilution limit. In this study, the primary intake runners are partially blocked to produce different levels of tumble motion in the cylinder during the air induction process. Experiments have been performed with a Chrysler 2.4L 4-valve I4 engine at maximum brake torque timing under two operating conditions: 2.41 bar brake mean effective pressure (BMEP) at 1600 rpm, and 0.78 bar BMEP at 1200 rpm. A method has been developed to quantify the tumble characteristics of blockages under steady flow conditions in a flow laboratory, by using the same cylinder head, intake manifold, and tumble blockages from the engine experiments.

In-cylinder charge motion is known to significantly increase turbulence intensity, accelerate combustion rate, and reduce cyclic variation. This, in turn, extends the tolerance to exhaust gas recirculation (EGR), while the introduction of EGR results in much lowered nitrogen oxide (NOx) emissions and reduced fuel consumption. The present study investigates the effect of charge motion in a spark ignition engine on fuel consumption, combustion, and engine-out emissions with stoichiometric and EGR-diluted mixtures under part-load operating conditions. Experiments have been performed with a Chrysler 2.4L 4-valve I4 engine under 2.41 bar brake mean effective pressure at 1600 rpm over a spark range around maximum brake torque timing. The primary intake runners are partially blocked to create different levels of tumble, swirl, and cross-tumble (swumble) motion in the cylinder before ignition.

Many different studies have been performed to understand brake roughness, and in particular how brake rotor Disc Thickness Variation (DTV) is generated. The intent of this paper is to analytically explore through non- linear finite element modeling methods the effects of wheel joint variables on brake rotor mounted Lateral RunOut (LRO). The phenomenon of LRO is believed to be a primary contributor to DTV generation and resulting brake roughness. CAE analyses were conducted in non-linear contact mechanics in which real contacts between components exist. Various joint designs were simulated to compare rotor LRO and coning. Several parameters inherent to the design of wheel joints were varied and studied. A comparative approach was used to develop specific design recommendations for LRO reductions.

This paper describes a front road wheel steer-by-wire system with two actuator motors on the rack and pinion assembly to move the road wheels. Dual actuators are used to provide actuator redundancy and to enhance the fault tolerance capability. When one actuator faults or fails, the other actuator is designed to work independently and maintain full system performance. The paper emphasizes control method to implement the motion control for the front road wheel steer-by-wire system with two actuators on the common load. The proposed dual servo synchronization motion control implements the angle tracking for the road wheel reference input by controlling two actuators synchronously and cooperatively. It includes two servo feedback control loops to track the common reference input. The angular position error between two feedback loops is compensated using a synchronized compensator.

The traditional method of engine knock detection is to compare the knock intensity with a predetermined threshold. The calibration of this threshold is complex and difficult. A statistical knock detection method is proposed in this paper to reduce the effort of calibration. This method dynamically calculates the knock threshold to determine the knock event. Theoretically, this method will not only adapt to different fuels but also cope with engine aging and engine-to-engine variation without re-calibration. This method is demonstrated by modeling and evaluation using real-time engine dynamometer test data.

This paper presents the studies on how to efficiently and easily implement ECU application algorithms using the Signal Processing Engine (SPE) of the Copperhead microcontroller. With the introduced development and testing concepts and methods, users can easily establish their own PC based SPE emulation system. All application unit testing and verification work for the fixed point implementation using SPE functions can be easily conducted in PC without relying on a costly real time test bench and expensive third party dedicated software. With this simple development environment, the code can be run in both embedded controllers and PCs with exact bit to bit numerical behavior. The paper also demonstrates many other benefits such as code statistics information retrieval, floating simulation mode, automated code verification, online and offline code sharing.

The requirement of reduced emissions and improved fuel economy led the introduction of direct-injection (DI) spark-ignited (SI) engines. Dual-fuel injection system (direct-injection and port-fuel-injection (PFI)) was also used to improve engine performance at high load and speed. Ethanol is one of the several alternative transportation fuels considered for replacing fossil fuels such as gasoline and diesel. Ethanol offers high octane quality but with lower energy density than fossil fuels. This paper presents the combustion characteristics of a single cylinder dual-fuel injection SI engine with the following fueling cases: a) gasoline for PFI and DI, b) PFI gasoline and DI ethanol, and c) PFI ethanol and DI gasoline. For this study, the DI fueling portion varied from 0 to 100 percentage of the total fueling over different engine operational conditions while the engine air-to-fuel ratio remained at a constant level.

Based on Woodbury-Sherman-Morrison formula, a general and efficient method for torsional damper tuning is presented. This method is based on exact calculation of the resulting Frequency Response Functions (FRF's) of the system with the damper by using the original (old) FRF's of the original (baseline) system and the damper's parameters (the mass polar moment of inertia, stiffness and damping coefficient). The only requirement for this method is to have the baseline FRF's at the active points of the structure where the damper is to be attached and those point where the resulting FRF's are of interest. The baseline FRF's can be obtained by either analytical or experimental methods. Once this requirement is met, all possible scenarios of the dampers for their potential and feasibility can be efficiently evaluated before being put into service without the need for costly hardware modification and test cycles on actual structure.

Tuned mass dampers (TMDs) or vibration absorbers are widely used in the industry to address various NVH issues, wherein, tactile-vibration or noise mitigation is desired. TMDs can be classified into two categories, namely, tuned-to-resonance and tuned-to-discrete-excitation. An overwhelming majority of TMD applications found in the industry belong to the tuned-to-resonance category, so much of information is available on design considerations of such dampers; however, little is published regarding design considerations of dampers tuned-to-discrete-excitation. During this study, a problem was solved that occurred at a discrete excitation frequency away from the primary resonance frequency of a steering column-wheel assembly. A solution was developed in multiple stages. First the effects of various factors such as mass and damping were analyzed by using a closed-form solution.

This paper focuses on the numerical investigation of the mixing and combustion of ethanol and gasoline in a single-cylinder 3-valve direct-injection spark-ignition engine. The numerical simulations are conducted with the KIVA code with global reaction models. However, an ignition delay model mitigates some of the deficiencies of the global one-step reaction model and is implemented via a two-dimensional look-up table, which was created using available detailed kinetics models. Simulations demonstrate the problems faced by ethanol operated engines and indicate that some of the strategies used for emission control and downsizing of gasoline engines can be employed for enhancing the combustion efficiency of ethanol operated engines.

Because combustion engine equipped vehicles must conform to stringent hydrocarbon (HC) emission requirements, many of them on the road today are equipped with an engine air intake system that utilizes a hydrocarbon adsorber. Also known as HC traps, these devices capture environmentally dangerous gasoline vapors before they can enter the atmosphere. A majority of these adsorbers use activated carbon as it is cost effective and has excellent adsorption characteristics. Many of the procedures for evaluating the adsorbtive performance of these emissions devices use mass gain as the measurand. It is well known that activated carbon also has an affinity for water vapor; therefore it is useful to understand how well humidity must be controlled in a laboratory environment. This paper outlines investigations that were conducted to study how relative humidity levels affect an activated carbon hydrocarbon adsorber.

Internal combustion engines are designed to maximize power subject to meeting exhaust emission requirements and minimizing fuel consumption. Maximizing engine power and fuel economy is limited by engine knock for a given air-to-fuel charge. Therefore, the ability to detect engine knock and run the engine at its knock limit is a key for the best power and fuel economy. This paper shows inaudible knock detection ability using in-cylinder ionization signals over the entire engine speed and load map. This is especially important at high engine speed and high EGR rates. The knock detection ability is compared between three sensors: production knock (accelerometer) sensor, in-cylinder pressure and ionization sensors. The test data shows that the ionization signals can be used to detect inaudible engine knock while the conventional knock sensor cannot under some engine operational conditions.

MBT timing for an internal combustion engine is also called minimum spark timing for best torque or the spark timing for maximum brake torque. Unless engine spark timing is limited by engine knock or emission requirements at a certain operational condition, there exists an MBT timing that yields the maximum work for a given air-to-fuel mixture. Traditionally, MBT timing for a particular engine is determined by conducting a spark sweep process that requires a substantial amount of time to obtain an MBT calibration. Recently, on-line MBT timing detection schemes have been proposed based upon cylinder pressure or ionization signals using peak cylinder pressure location, 50 percent fuel mass fraction burn location, pressure ratio, and so on. Because these criteria are solely based upon data correlation and observation, both of them may change at different engine operational conditions. Therefore, calibration is still required for each MBT detection scheme.

In the absence of prototypes, analytical methods such as finite element analysis are very useful in resolving noise and vibration problems, by predicting dynamic behavior of the automotive components and systems. Finite Element Analysis (FEA) is a simulation technique and involves making assumptions that affect analytical results. Acceptance and use of these results is greatly enhanced through test validation. In this paper, dynamic behavior of the automotive propshaft equipped with cardboard liner and torsional damper is investigated. The finite element model is validated at both component and subsystem levels using frequency response functions. Effects of the cardboard liner and torsional damper on the propshaft bending, torsional and breathing frequencies are studied under free-free boundary conditions. Effects of the U-Joint stiffness along with other design variables on the driveshaft dynamic behavior are also studied.

This paper discusses the development of combination vehicle stability program (CVSP) at Visteon. It will describe why stability control is needed for combination vehicles and how the vehicle stability can be improved. We propose and evaluate controller structures and design methods for CVSP. These include driver's intent identification, combination vehicle status estimation and control, and fault detection / tolerance. In this paper, the braking and steering dynamics of car-trailer and tractor-semitrailer combinations, and the brake systems which should be used extensively to increase the stability of combination vehicles are presented. Also our development platform is introduced and the combination vehicle simulation results are presented. The definition of combination vehicles in this paper includes car-trailer and commercial tractor-semitrailer combinations since their vehicle dynamics are based on the same equations of motion.

The objective of the present work was to improve the cold start NVH performance of an automotive power steering pump under low temperature conditions. This objective was accomplished through the use experimental study and measurement. The satisfactory operation of a fixed displacement vane pump in cold temperatures depends on a number of factors including; (1) filling characteristics, (2) the inlet conditions to the pump, (3) the fluid, and (4) the ability of the vanes to maintain contact with the cam surface. In this investigation, factor (4) was chosen for investigation. A unique outlet orifice was designed and tested at three different operating ambient temperatures, -19 °C, -29 °C, and -40 °C. Maximum “noise” duration was measured as the maximum duration of fluid borne pump outlet pressure oscillations greater the 345 kPa peak-to-peak. The results show that noise duration can reduced by as much as 50% at -40 °C.

Stabilizer bars in a suspension system are supported with bushings by a frame structure. To prevent the axial movement of the stabilizer bar within the bushing, several new stabilizer bar-bushing systems have been developed. The new systems introduce permanent compressive force between the bar and the bushing thereby preventing the relative movement of the bar within the bushing. This mechanical bond between the bar and the bushing can eliminate features such as grippy flats, collars etc. In addition, by controlling the compression parameters, the properties of the bushing such as bushing rates can be tuned and hence can be used to improve the ride and handling performance of the vehicle. In this paper, nonlinear CAE tools are used to evaluate one such compressively loaded bushing system. Computational difficulties associated with modeling such a system are discussed.

Generalized predictive control (GPC) is a discrete time control strategy proposed by Clark et al [1]. The controller tries to predict the future output of a system or plant and then takes control action at present time based on future output error. Such a predictive control algorithm is presented in this paper for deceleration slip regulation in an automobile. Most of the existing literature on the anti-lock brake control systems lacks the effectiveness of the wheel lockup prevention when the automobile is in a skid condition (in a low friction coefficient surface with panic braking situation). Simulation results show that the predictive feature of the proposed controller provides an effective way to prevent wheel lock-up in a braking event.

The quietness of the interior of automobiles is perceived by consumers as a measure of quality and luxury. Great strides have been achieved in isolating interiors from noise sources. As noise is reduced, in particular wind and power train noise, other noise sources become evident. Noise reduction efforts are now focused on components like power steering pumps. To understand the contribution of power steering pumps a world-class noise and vibration test stand was developed. This paper describes the development of the test stand as well as it's objective to understand and improve the sound quality of power steering pumps.