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The demand for improved fuel economy in both cars and trucks has emphasized the need for lighter weight components. The application of high strength steel to wheels, both rim and disc, represents a significant opportunity for the automotive industry. This paper discusses the Ranger HSLA wheel program that achieved a 9.7 lbs. per vehicle weight savings relative to a plain carbon steel wheel of the same design. It describes the Ranger wheel specifications, the material selection, the metallurgical considerations of applying HSLA to wheels, and HSLA arc and flash butt welding. The Ranger wheel design and the development of the manufacturing process is discussed, including design modifications to accommodate the lighter gage. The results demonstrate that wheels can be successfully manufactured from low sulfur 60XK HSLA steel in a conventional high volume process (stamped disc and rolled rim) to meet all wheel performance requirements and achieve a significant weight reduction.

The 2005 Ford GT high performance sports car was designed and built in keeping with the heritage of the 1960's LeMans winning GT40 while maintaining the image of the 2002 GT40 concept vehicle. This paper reviews the technical challenges in designing and building a super car in 12 months while meeting customer expectations in performance, styling, quality and regulatory requirements. A team of dedicated and performance inspired engineers and technical specialists from Ford Motor Company Special Vehicle Teams, Research and Advanced Engineering, Mayflower Vehicle Systems, Roush Industries, Lear, and Saleen Special Vehicles was assembled and tasked with designing the production 2005 vehicle in record time.

The main objective of the current paper was to investigate the fluid flow and pressure loss characteristics of DPF substrates with asymmetric channels utilizing 3-D Computational Fluid Dynamics (CFD) methods. The ratio of inlet to outlet channel width is 1.2. First, CFD results of velocity and static pressure distributions inside the inlet and outlet channels are discussed for the baseline case with both forward and reversed exhaust flow. Results were also compared with the regular DPF of same cell structure and wall material properties. It was found that asymmetrical channel design has higher pressure loss. The lowest pressure loss was found for the asymmetrical channel design with smaller inlet channels. Then, the effects of DPF length and filter wall permeability on pressure loss, flow and pressure distributions were investigated.

Squeak and rattle has become a primary source of undesired noise in automobiles due to the continual diminishment of engine, power train and tire noise levels. This article presents a finite-element-based methodology for the improvement of rattle performance of vehicle components. For implementation purposes, it has been applied to study the rattle of a glove compartment latch and corner rubber bumpers. Results from the glove compartment study are summarized herein. Extensions to other rattle problems are also highlighted.

Topology optimization is used for obtaining the best layout of vehicle structural components to achieve predetermined performance goals. Unlike the most common approach which uses the optimality criteria methods, the topology design problem is formulated as a general optimization problem and is solved by the mathematical programming method. One of the major advantages of this approach is its generality; thus it can solve various problems, e.g. multi-objective and multi-constraint problems. The MSC/NASTRAN finite element code is employed for response analyses. Two automotive examples including a simplified truck frame and a truck frame crossmember are presented.

This paper presents a simplified concept of the cab-over-engine tractor ride problem. It discusses ways ride can be improved and the reasons cab suspension was chosen as the preferred solution. It describes the Ford CL-9000 cab suspension, explains why it improves ride and includes some data to indicate the benefits that are realized.

There have been many articles published in the last decade or so concerning the components of an electronic stability control (ESC) system, as well as numerous statistical studies that attempt to predict the effectiveness of such systems relative to crash involvement. The literature however is free from papers that discuss how engineers might develop such systems in order to achieve desired steering, handling, and stability performance. This task is complicated by the fact that stability control systems are very complex and their designs and what they can do have changed considerably over the years. These systems also differ from manufacturer to manufacturer and from vehicle to vehicle in a given maker of automobiles. In terms of ESC hardware, differences can include all the components as well as the addition or absence of roll rate sensors or active steering gears to name a few.

Computer simulation of the behavior of the automotive cooling system is becoming increasingly common, so as to reduce the dependency on costly testing. The simulation of transient cooling system behavior has become easier with the use of 1-D simulation tools. However, accurate prediction of transient coolant temperature after thermostat operation has been limited by the difficulty in accurately modeling the behavior of the automotive thermostat. Physical models of the thermostat are often inaccurate due to the complexity of the thermostat. Therefore an empirical model has been developed, which can be used to model any automotive thermostat, once a few simple tests have been conducted on the part. This thermostat model can be used in conjunction with a 1-D flow simulation tool to predict coolant transient temperature response during thermostat operation.

Drivelines used in modern pickup trucks commonly employ universal joints. This type of joint is responsible for second driveshaft order vibrations in the vehicle. Large displacements of the joint connecting the driveline and the rear axle have a detrimental effect on vehicle NVH. As leaf springs are critical energy absorbing elements that connect to the powertrain, they are used to restrain large axle windup angles. One of the most common types of leaf springs in use today is the multi-stage parabolic leaf spring. A simple SAE 3-link approximation is adequate for preliminary studies but it has been found to be inadequate to study axle windup. A vast body of literature exists on modeling leaf springs using nonlinear FEA and multibody simulations. However, these methods require significant amount of component level detail and measured data. As such, these techniques are not applicable for quick sensitivity studies at design conception stage.

A new, systematic, sensitivity based design process for weight reduction is presented. Traditionally, a trial and error method is used when a design fails to meet the weight and the design criteria, which often conflict. This old approach not only is time and cost consuming but also does not provide insight into structural behavior. This proposed process uses state-of-the-art technologies such as design sensitivity analysis, numerical optimization, graphical user interface, etc. It handles multi-discipline design criteria simultaneously and provides design engineers insight into structural responses for frequency, durability, and stiffness concerns and a means for systematic weight reduction and quality improvement. The new design process has been applied for the weight reduction of advanced truck frame designs. Results show that a significant weight savings has been achieved while all design criteria are met.

As automakers strategize approaches to sustainable vehicle technologies, alternative powertrains must be considered to reduce future fleet vehicle emissions and improve energy security. These alternative vehicles include different fuels and electrification. The ultimate for on-road CO2 reductions is a zero emission vehicle, which can be achieved by either a hydrogen fuel cell or battery electric vehicle. These vehicles would also require a renewable energy source to provide their propulsion energy in order to achieve maximum sustainability for both CO2 reduction and energy security. Renewable energy sources such as wind or solar result in heat or electricity that needs to be generated into an energy carrier such as hydrogen or stored in a battery. When examining these options based strictly on the efficiency path, previous analysis have concluded fuel cell vehicles may not be an appropriate suitability strategy in comparison to battery electric vehicles.

An analytical model based on “vortex sound” theory was investigated for predicting the frequency, the relative magnitude, the onset, and the offset of self-sustained interior pressure fluctuations inside a vehicle with an open sunroof. The “buffeting” phenomenon was found to be caused by the flow-excited resonance of the cavity. The model was applied to investigate the optimal sunroof length and width for a mid-size sedan. The input parameters are the cavity volume, the orifice dimensions, the flow velocity, and one coefficient characterizing vortex diffusion. The analytical predictions were compared with experimental results obtained for a system which geometry approximated the one-fifth scale model of a typical vehicle passenger compartment with a rectangular, open sunroof. Predicted and observed frequencies and relative interior pressure levels were in good agreement around the “critical” velocity, at which the cavity response is near resonance.

This paper provides an overview of the dual EGO sensor method for OBD-II catalyst efficiency monitoring. The processes governing the relationship between catalyst oxygen storage, HC conversion efficiency, and rear EGO sensor response are reviewed in detail. A simple physical model relating catalyst oxygen storage capacity and rear EGO sensor response is constructed and used in conjunction with experimental data to provide additional insight into the operation of the catalyst monitor. The effect that the catalyst washcoat formulation has in determining the relationship between catalyst oxygen storage capacity and HC conversion efficiency and its impact on the catalyst monitor is also investigated. Lastly, the effects of catalyst failure mode, fuel sulfur, and the fuel additive MMT on the catalyst monitor's ability to properly diagnose catalyst function are discussed.

In vehicle crash tests, an unbelted occupant's kinetic energy is absorbed by the restraints such as an air bag and/or knee bolster and by the vehicle structure during occupant ride-down with the deforming structure. Both the restraint energy absorbed by the restraints and the ride-down energy absorbed by the structure through restraint coupling were studied in time and displacement domains using crash test data and a simple vehicle-occupant model. Using the vehicle and occupant accelerometers and/or load cell data from the 31 mph barrier crash tests, the restraint and ride-down energy components were computed for the lower extremity, such as the femur, for the light truck and passenger car respectively.

This paper contains a technical description of the Ford Motor Co.'s ACT system which has been designed to meet transportation needs in a wide variety of urban applications. The discussion covers the systems design features and operation of the driverless rubber-tired vehicles, the guideway, and the system's ability to meet expanding needs by a modular approach to the command and control design. Descriptions of Ford's new Cherry Hill Test Track and the first installations at the Fairlane Town Center in Dearborn, Mich., and the Bradley International Airport, Hartford, Conn., are also presented.

The Auto Industry is responding to the environment and energy conservation concerns by ramping up production of hybrid electric vehicles (HEV). As the initial hurdles of making the powertrain operate are overcome, challenges such as making the powertrain feel more refined and intuitive remain. This paper investigates one of the key parameters for delivering that refinement: engine RPM behavior. Ideal RPM behavior is explored and included in the design of a control system. System implications are examined with regard to the effect of engine RPM scheduling on Battery usage and vehicle responsiveness.

The design requirements for the frame as a load carrying member are discussed in relationship to a highway truck and its basic vehicle package. The theoretical and experimental procedures are given in detail to demonstrate the techniques for frame design. The features of a method to laboratory test a frame with correlation to service miles is discussed.

This paper discusses in detail three applications of photoelasticity to engine component design and failure analysis. This stress analysis technique provides whole field stress distribution and can also be used to optimize a design by obtaining even stress distribution. The applications discussed cover several aspects of photoelasticity such as two and three dimensional model analysis, stress freezing, thermal and mechanical loading simulation. These are some of the many investigations conducted by the authors and can be used as a guide to many other applications. The results of the analysis have been verified during endurance testing, but are not discussed in this paper.

Evolving the current state of the art Hybrid Technology for vehicles with plug-in capability will yield three significant results, the displacement of petroleum with electricity for transportation, improved efficiency and reduced emissions. As the technology evolves from the Ford Escape Hybrid Plug-In demo fleet, Ford is in the final stages of development of the C-Max Energi, which will be delivered in 2012 as a highly efficient, full purpose vehicle designed to meet customer expectations without compromise. Presenter Charles Gray, Ford Motor Co.

Two types of catalysts were tested in a fleet of twenty-four 1969 vehicles, operated in customer-type urban driving regimes, on both leaded and nonleaded fuels over a period of 18 months. The two catalyst types and the converter systems chosen for this evaluation were selected on the basis of information obtained from an earlier test program involving four cars that were durability tested on a more rapid “test track mileage accumulation cycle.” Comparisons are made between the vehicles running rapid mileage accumulation and the vehicles running slower customer-type mileage accumulation. Catalyst life and system performance depreciation were relatively similar in both fleets and did not seem to be significantly affected by the method of mileage accumulation. The 24-vehicle fleet was equipped with a programmed protection system (PPS) designed to protect the catalysts from damage due to over-temperature operation. Problems with this prototype protection system are discussed.