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The number of control actuators available on spark-ignition engines is rapidly increasing to meet demand for improved fuel economy and reduced exhaust emissions. The added complexity greatly complicates control strategy development because there can be a wide range of potential actuator settings at each engine operating condition, and map-based actuator calibration becomes challenging as the number of control degrees of freedom expand significantly. Many engine actuators, such as variable valve actuation and flow control valves, directly influence in-cylinder combustion through changes in gas exchange, mixture preparation, and charge motion. The addition of these types of actuators makes it difficult to predict the influences of individual actuator positioning on in-cylinder combustion without substantial experimental complexity.

Two methods for analyzing and evaluating the environmental control system on an advanced aircraft as described in this paper include the conventional first law energy conservation technique and the second law entropy generation minimization technique. Simplified analytical models of the ECS are developed for each method and compared to determine the validity of using the latter to facilitate the design process in optimizing the overall system for a minimum gross takeoff weight (GTW). Preliminary results have illustrated the importance of taking into account system optimization based on system (or component) efficiency. For instance, even though different values were obtained for the rate of entropy generation, the second law analysis of a shell-in-tube heat exchanger led to an optimum tube diameter of 0.12 in (3.05 mm) when both R-12 and R-114 were used as the refrigerant in the vapor cycle.

With their high specific strength and stiffness, composites have the potential to significantly lower the vehicle weight, which can have a dramatic effect on improving fuel efficiency and reducing greenhouse gas emissions. For the past decade or so, composites have been experiencing several transitions, including the transition from micro-scale reinforcement fillers to nano-scale reinforcement fillers, resulting in the nanocomposite. The effectiveness of the nano-sized fillers in composites can be explained by one of their unique geometric properties: the length-to-thickness aspect ratio. Therefore, nano-sized fillers have exceptionally higher reinforcing efficiency than the conventional, large fillers. The effectiveness of the nano-sized fillers in composites is also due to their large surface area and surface energy.

A nonlinear eight degree of freedom vehicle model has been used to examine the effects of roll stiffness on handling and performance. In addition, various control strategies have been devised which vary the total roll couple distribution in order to improve cornering capability and stopping distance. Of all cases tested, a controller which varies the total roll stiffness based on roll angle feedback, and continuously updates the roll couple distribution as a function of steering wheel angle, braking input, and the total roll stiffness, yields the greatest improvements in collision avoidance.

Predictable handling of a racecar may be achieved by tailoring chassis stiffness so that roll stiffness between sprung and unsprung masses are due almost entirely to the suspension. In this work, the effects of overall chassis flexibility on roll stiffness and wheel camber response, will be determined using a finite element model (FEM) of a Winston Cup racecar chassis and suspension. The FEM of the chassis/suspension is built from an assembly of beam and shell elements using geometry measured from a typical Winston cup race configuration. Care has been taken to model internal constraints between degrees-of-freedom (DOF) at suspension to chassis connections, e.g. t ball and pin joints and internal releases. To validate the model, the change in wheel loads due to an applied jacking force that rolls the chassis agrees closely with measured data.

This paper documents an inverse visible element Rayleigh integral (VERI) approach. The VERI is a fast though approximate method for predicting sound radiation that can be used in the place of the boundary element method. This paper extends the method by applying it to the inverse problem where the VERI is used to generate the acoustic transfer matrix relating the velocity on the surface to measurement points. Given measured pressures, the inverse VERI can be used to reconstruct the vibration of a radiating surface. Results from an engine cover and diesel engine indicate that the method can be used to reliably quantify the sound power and also approximate directivity.

Rollover prevention is now part of complete vehicle stability control systems for many vehicles. Given that rollover is predominantly associated with vehicles with high centers of gravity, the targeted vehicles for rollover protection include medium and heavy duty commercial vehicles. Unfortunately, the chassis designs of these vehicles are often so compliant in torsion that the ends of the vehicles may have significantly different roll responses at any given time. The potential need to assess and correct for the roll behavior of the front and rear ends of the vehicle is the subject of this paper. Most rollover mitigation research to date has used rigid chassis assumptions in modeling the vehicle. This paper deals with the roll control of vehicles with torsionally flexible chassis based on a yaw-correction system.

In today's business climate rapid access to, and implementation of, new technology is essential to enhance competitive advantage. In the past, universities have been used for research contracts, but to fully utilize the intellectual resources of education institutions, it is essential to approach these relationships from a new basis: alliance. Alliances permit both parties to become active participants and achieve mutually beneficial goals. This paper will examine the drivers and challenges for industrial -- university alliances from both the industrial and academic perspectives.

In developing a nonlinear steering system model for vehicle simulation, it was determined that proper inclusion of system friction is necessary to correctly predict steering wheel torque response in on-center driving using simulation models. A method to characterize the inherent friction behavior for a given steering gear has been developed and performed on two types of power steering gears: a recirculating ball gear and a rack-and-pinion gear. During this research it was discovered that levels of static and dynamic friction can differ widely for these two types. Therefore this characterization procedure provides a method to ascertain both static and dynamic friction levels. The results from these tests show that friction levels can depend on steering gear input shaft position, steering gear input angular velocity and steering gear loading conditions.

Medium-carbon, microalloyed forging steels represent a cost effective replacement of quenched and tempered grades. Their strength properties are derived from precipitation during cooling from the forging temperature. Because of the relatively high carbon content, vanadium is the most suitable addition to achieve precipitation strengthening. The effectiveness of vanadium is enhanced by the presence of nitrogen. For components subjected to impact loading, improvement in toughness is achieved by refining austenitic grains, pinning their boundaries by means of dispersed titanium nitrides. Precipitation strengthened ferrite-pearlite steels exhibit superior machinability compared to that of quenched and tempered alloy steels. As a result, the total machining costs are substantially reduced compared to the costs of machining heat-treated steels. The frequency of tool breakage and tool changes decrease dramatically, virtually eliminating line scrap and unnecessary downtime.

Covers the approach used by Caterpillar Inc. in working with Auxiliary Equipment Manufacturers to increase the versatility of backhoe loaders.

A multidimensional simulation of Auxiliary Gas Injection (AGI) for late cycle oxygen enrichment was exercised to assess the merits of AGI for reducing the emissions of soot from heavy duty diesel engines while not adversely affecting the NOx emissions of the engine. Here, AGI is the controlled enhancement of mixing within the diesel engine combustion chamber by high speed jets of air or another gas. The engine simulated was a Caterpillar 3401 engine. For a particular operating condition of this engine, the simulated soot emissions of the engine were reduced by 80% while not significantly affecting the engine-out NOx emissions compared to the engine operating without AGI. The effects of AGI duration, timing, and orientation are studied to confirm the window of opportunity for realizing lower engine-out soot while not increasing engine out NOx through controlled enhancement of in-cylinder mixing.

The highly transient operational nature of passenger car engines makes cylinder pressure based feedback control of combustion phasing difficult. The problem is further complicated by cycle-to-cycle combustion variation. A method for fast and accurate differentiation of normal combustion variations and true changes in combustion phasing is addressed in this research. The proposed method combines the results of a feed forward combustion phasing prediction model and “noisy” measurements from cylinder pressure using an iterative estimation technique. A modified version of an Extended Kalman Filter (EKF) is applied to calculate optimal estimation gain according to the stochastic properties of the combustion phasing measurement at the corresponding engine operating condition. Methods to improve steady state CA50 estimation performance and adaptation to errors are further discussed in this research.

A direct-injection natural gas (DING) engine was modified for optical access to allow the use of laser diagnostic techniques to measure species concentrations and temperatures within the cylinder. The injection and mixing processes were examined using planar laser-induced fluorescence (PLIF) of acetone-seeded natural gas to obtain qualitative maps of the fuel/air ratio. Initial acetone PLIF images were acquired in a quiescent combustion chamber with the piston locked in a position corresponding to 90° BTDC. A series of single shot images acquired in 0.1 ms intervals was used to measure the progression of one of the fuel jets across the cylinder. Cylinder pressures as high as 2 MPa were used to match the in-cylinder density during injection in a firing engine. Subsequent images were acquired in a motoring engine at 600 rpm with injections starting at 30, 20, and 15° BTDC in 0.5 crank angle degree increments.

Due to titanium's excellent strength-to-weight ratio and high corrosion resistance, titanium and its alloys have great potential to reduce energy usage in vehicles through a reduction in vehicle mass. The mass of a road vehicle is directly related to its energy consumption through inertial requirements and tire rolling resistance losses. However, when considering the manufacture of titanium automotive components, the machinability is poor, thus increasing processing cost through a trade-off between extended cycle time (labor cost) or increased tool wear (tooling cost). This fact has classified titanium as a “difficult-to-machine” material and consequently, titanium has been traditionally used for application areas having a comparatively higher end product cost such as in aerospace applications, the automotive racing segment, etc., as opposed to the consumer automotive segment.

How will a mechanic troubleshoot the heavy duty vehicle of the future? Will he or she have to be both retriever and integrator of data collected from multiple black boxes on the vehicle? How many tools will it take? Is there a definition of a vehicle system “diagnostic environment” that needs to be developed in order to create a solution to this problem? This paper will attempt to create the system focus for vehicle diagnostics that is required if this industry is to successfully produce the integrated electronic vehicle of the future. Both the on-board and off-board requirements of the diagnostic environment will be examined.

As engines are equipped with an increased number of control actuators to meet fuel economy targets, they become more difficult to control and calibrate. The additional complexity created by a larger number of control actuators motivates the use of physics-based control strategies to reduce calibration time and complexity. Combustion phasing, as one of the most important engine combustion metrics, has a significant influence on engine efficiency, emissions, vibration and durability. To realize physics-based engine combustion phasing control, an accurate prediction model is required. This research introduces physics-based control-oriented laminar flame speed and turbulence intensity models that can be used in a quasi-dimensional turbulent entrainment combustion model. The influence of laminar flame speed and turbulence intensity on predicted mass fraction burned (MFB) profile during combustion is analyzed.

Hydrostatic (hydraulic hybrid) drives have demonstrated energy efficiency and emissions reduction benefits. This paper investigates the potential of an independent hydrostatic wheel drive system for implementing a traction-based vehicle lateral stability control system. The system allows an upper level vehicle stability controller to produce a desired corrective yaw moment via a differential distribution of torque to the independent wheel motors. In cornering maneuvers that require braking on any one wheel of the vehicle, the motors can be operated as pumps for re-generating energy into an on-board accumulator. This approach avoids or reduces activation of the friction brakes, thereby reducing energy waste as heat in the brake pads and offering potential savings in brake maintenance costs. For this study, a model of a 4×4 hydrostatic independent wheel drive system is constructed in a causal and modular fashion and is coupled to a 7 DOF vehicle handling dynamics model.

The critical particle size for a high-pressure injection system was determined. Various double-cut test dusts ranging from 0 to 5 μm to 10 to 20 μm were evaluated to determine which test dust caused the high-pressure system to fail. With the exception of the 0- to 5-μm test dust, all test dust ranges caused failure in the high-pressure injection system. Analysis of these evaluations revealed that the critical particle size, in initiating significant abrasive wear, is 6 to 7 μm. Wear curve formulas were generated for each evaluation. A formula was derived that allows the user to determine if the fuel filter effluent will cause harmful damage to the fuel system based on the number of 5-, 10-, and 15-μm particles per milliliter present. A methodology was developed to evaluate fuel filter performance as related to engine operating conditions. The abrasive methodology can evaluate online filter efficiency and associated wear in a high-pressure injection system.

Three-dimensional simulation has become an indispensable approach to develop improved understanding of ring rolling technology, with validity as the basic requirement of the ring rolling simulation. Cold ring rolling is simple conceptually, however complex to analyze as the metal forming process is subject to coupled effects with multiple influencing factors such as sizes of rolls and ring blank, form geometry, material, process parameters, and frictional effects. Investigating the coupled thermal and plastic deformation behavior (the plastic deformation state and its development) in the deformation zone during the process is significant for predicting metal flow in order to control the geometric and tensile residual stress quality of deformed rings, and to provide for cycle time optimization of the cold ring rolling process.