Search Results

The determination of the total antioxidant capacity of new and used automatic transmission fluids can yield information useful in the study of fluid stability, severity of service and correlation between bench tests and service. The technique is particularly useful in the characterization of the earlier stages of fluid oxidation where parameters such as T.A.N., pentane insolubles and viscosity yield little information. Three fluids from a fleet test manifested different antioxidant decay profiles. Data obtained from a laboratory beaker test indicate that some test conditions can reproduce these decay curves and thus simulate the primary oxidation processes occurring in the transmission in this fleet.

A method is presented for optimizing the engine/secondary usage strategy of a hybrid vehicle. A powertrain simulation is combined with dynamic programming techniques for calibration optimization, and a sequential decision algorithm for specifying optimal operating points for both engine and secondary drive systems. An overview of road-load matching and strategy requirements is presented.

The following paper has been prepared to describe the procedures used by the Vought Corporation to fabricate automotive body components in graphite reinforced plastic for the Ford Motor Company Graphite 1979 Ford LTD. This effort was a joint venture by the Milford Fabricating Company - a subsidiary of the Budd Company - and the Vought Corporation. Graphite Fiber Reinforced Plastic, the specified material for the major body components made it necessary to unite proven aerospace methods with current automotive prototype technology to ensure successful completion of the project. Areas to be discussed will be the master tooling aid development, high temperature epoxy molds, and component fabrication.

An experimental LTD chassis frame, for a 1979 Ford experimental vehicle, was designed and fabricated in graphite-reinforced plastic. Prototype composite moldingtechniques were employed to form the closed frame sections required for strength and stiffness. Weight savings were realized because of both component integration and material substitution: compared with its steel counterpart, the graphite frame afforded a 79 pound weight reduction while providing a 33% increase in torsional stiffness and a 16% increase in bending stiffness. The frame passed laboratory suspension and steering load tests and has been incorporated in the experimental vehicle, but not vehicle tested.

A new as-hot-rolled HSLA steel has been developed for application as round and flat bars. This material possesses a minimum yield strength of 80 ksi coupled with good bendability, weldability, and fatigue performance. This material offers design engineers and manufacturers the flexibility to upgrade from lower-strength materials to (a) increase load carrying capability of their present structures or, (b) realize important weight and energy savings by going to lighter section sizes at present load ratings. It also enables them to take advantage of its high strength to replace more costly heat treated grades.

The following paper has been prepared to describe the procedures used to fabricate and assemble a lightweight demonstration vehicle, built under contract to Ford Motor Company. G.F.R.P. (Graphite Fiber Reinforced Plastic), the specified material for the major body components, made it necessary to combine state-of-the-art aerospace manufacturing methods with current automotive prototype technology to ensure successful completion of the project. Major areas of emphasis include; master tooling aid development, high temperature epoxy molds, component fabrication, component subassembly and body assembly. These areas will be discussed in detail, along with the completion and final assembly of the lightweight vehicle.

This paper describes a distinct approach in making technological forecasts. From historical data, fuel economy learning curves have been constructed for alternatives such as the Diesel, gas turbine, Stirling, stratified charge, and rotary engines. Assuming that evolutionary development will take place, projections of these learning curves are extended to the 1990 era. The investigation found that no engine is likely to exceed the fuel economy of the Diesel in the next 10-15 years. However, serious questions are being raised regarding the feasibility of controlling nitrogen oxides and unregulated emissions in future Diesel engines.

Results of an automotive technology assessment study are presented to provide a basis of comparison for vehicles with alternative power systems. Factors considered include fuel economy, exhaust emissions, multifuel capability, advanced materials, and cost/manufacturability for both conventional and advanced alternative power systems. To insure valid comparisons of vehicles with alternative power systems, the concept of an Otto-Engine-Equivalent (OEE) vehicle is utilized. Each engine type is sized to provide equivalent vehicle performance. Fuel economy projections are made for each engine type considering both the legislated emissions standards (0.4 g/mi HC, 3.4 g/mi CO, 1.0 g/mi NOx) and possible future emissions requirements (0.4 g/mi NOx). The sensitivities of the fuel economy projections to factors such as engine torque boundary, rear axle ratio, performance criteria, and engine transient response are discussed.

Microalloying is the technique of adding very small amounts of certain elements to steel in order to markedly improve the mechanical properties, most notably the strength and hardness. In 1977, the VanCraft series of high strength microalloyed cold finished bars was introduced. In 1978, this technique has been extended to include hot rolled bars for hot forging applications. Hot forging of steel bars is the technique employed to produce many critical automotive components such as connecting rods, stabilizer bars, and many others. Typically, these parts require subsequent heat treatment to obtain the necessary properties. By microalloying with Cb or V, this heat treatment can often be eliminated since the desired properties are met in the as-forged part. This provides a significant cost savings and, of course, results in a reduction in energy consumption.

Within the past decade, manufacturing processes have undergone significant technological improvements and have supported the burden of additional imposed restrictions. In light of these improvements and restrictions it is the intent of this paper to use automotive engine connecting rods as an example in applying an optimum manufacturing process selection algorithm for any part. Two hot forging alternatives, casting, hot formed powder metal, and precision warm forming are compared.

This paper describes the technical approach and development of methodologies used to conduct design trade studies from a Life Cycle Cost standpoint. A discussion of computer program capability is followed by a general discussion of several engine design trade studies. The potential for influencing engine design using a Life Cycle Cost methodology is emphasized.

To ensure cost effective programs, future military aircraft designs must more fully consider the sensitivity of weapon system life cycle cost to engine design life and duty cycle requirements. In many instances, the life of expensive engine parts can be extended with only a small change in cost or weight. This paper discusses the life cycle cost effects of the F100-PW-100 engine design life and duty cycle on the F-15 weapon system life cycle cost. The importance of establishing actual engine usage and duty cycle definitions early in the program and continual updating of these dynamic variables to minimize their impact on weapon system cost of ownership is shown.

In order to make better decisions during advanced development of turbine engines, life cycle cost (LCC) methodologies must adequately reflect the impact of engine design decisions on the total system LCC. Two applications of Teledyne CAE's APSICOST Methodology are presented herein. These demonstrate the integrated nature of turbine engine LCC analyses with total aircraft system LCC. It is recommended that a joint airframe/propulsion/government effort be undertaken to standardize methods for reflecting aircraft system LCC impacts in turbine engine advanced development activities.

The rising cost of Military Aircraft Systems during a period of declining purchasing power has forced the military and industry to make trade-offs of system and component performance against cost, even during the advanced technology stages of development. An evaluation tool is needed for use by the conceptual designer/evaluator to characterize these trade-offs properly. A computerized Life Cycle Cost Model has been developed that uses parametric data to help the designer to determine these trade-offs/cost values during advanced technology engine development stages. This computerized model includes airframe and mission considerations.

A T-63 combustor rig has been used to study the sensitivity of combustor performance to the physical and chemical properties of fuels. The purpose was to determine the impact of broadening fuel specifications and using non-specification fuels in emergencies. The fuel properties of special concern were the composition, the distillation curve and viscosity. The first property is associated with the chemistry of carbon formation while the latter two are related to mixing as they affect the atomization and vaporization. Six fuels were blended from a JP-5 base fuel and used to determine the effects of aromatic content, types of aromatics, and end point. Three JP-5s derived from coal, shale oil, and tar sands, were used to see if they correlated the same as the petroleum-derived fuels despite their different chemistry. Seven more fuels that were blends of marine diesel, JP5, and gasoline were used to examine all aspects but with emphasis on viscosity and distillation curve.

The F/A-18 Program is among the first to apply the Naval Air Systems Command “New Look Acquisition Fundamentals” from contract award. The New Look establishes firm requirements and incentives for achieving reliability and maintainability. It imposes stringent disciplines on design, test, and manufacturing to assure compliance to those requirements. In the case of the radar (at least), the level of reliability and maintainability specified could not be achieved by these disciplines alone. A substantial simplification of system architecture and its hardware (over previous tactical radars) was also required. This paper describes how that simplification was achieved, while at the same time gaining substantially in multimission capability. It also summarizes the status of key elements of the New Look program at this early stage of the development program.

The Department of Defense consumes approximately 2.7 percent of the total U.S. demand for petroleum. The Air Froce usage accounts for 57 percent of the DOD consumption with approximately 82 percent being consumed as jet fuel. The cost of this fuel to the Air Force has increased greatly since the 1973 oil embargo. The bill in 1973 was slightly over one-half billion dollars for 112 million barrels of JP-4, whereas, it is now approximately 1.6 billion dollars or about 6 percent of the Air Force annual budget for only 80 million barrels. This paper discusses an Air Force program which will result in adequate fuel availability for the Air Force at an acceptable cost. Results of recent processing studies on alternative hydrocarbon sources from shale oil are presented, together with combustor studies directed to determining the effects of property variations on combustor performance, durability and level of harmful emissions.

The U.S. Army CH-47D helicopter modernization program incorporates improvements in all major subsystems. The drive train has been redesigned to incorporate evolutionary improvements which will increase reliability, survivability, and maintainability. This paper describes the background experience that led to the selection of VASCO X-2 high-hot-hardness gear steel; it also discusses design improvements in the integration of components, in lubrication and diagnostic systems, in overrunning clutches, and in noise reduction. New capabilities to predict and measure gear bending stresses and resonant frequencies have been developed and are described as part of a systems design approach.

A description of the Lynx transmission is linked with the basic factors which determined its general form. This gear system is compared with other alternatives and an improved Lynx system is also shown which gives even higher load capacity. Some of the characteristics of the output stage Conformal gears are given, together with a description of a few of the development stages through which the gears have passed.

The successful procurement of hardware items with reliability R, maintainability M, and system safety SS requirements and R, M, and SS program requirements involves no particularly new or unusual techniques. It does require the consistent, disciplined use of several of the tools presently available, i.e., the item specification, a really comprehensive statement of work (SOW) and a data requirements list (CDRL). These all must be closely coordinated so that they “track together”. Clear distinctions between tasks to be accomplished, requirements for the design, and data items to be prepared are essential. Also, most system contractors need to better inform their potential suppliers.