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A graphical method for estimating the viscosity and other physical characteristics of three component blends of lubricating oil base stocks is presented. The method utilizes triangular coordinate paper in which “families” of straight lines show the variation of viscosity and other physical characteristics of three-component systems with composition. A modification of the principles is used to construct a viscosity index improver blending chart.

The demonstrated architectural model and associated graphical techniques defined herein were developed to provide a simple method of visualizing the general functional operation or behavior of a Distributed Embedded System with a strong emphasis on representing system time characteristics.

Load data representing severe customer usage is required during the chassis development process. One area of current research is the use of road profiles for predicting chassis loads. The most direct method of predicting these loads is to run dynamic simulations of the vehicle using numerous road profiles as the excitation. This onerous task may be avoided, and a greatly reduced number of simulations would be required, if roads having similar characteristics can be grouped. Currently, road profiles are characterized by their spectral content. It has been noted by several researches, however, that road profiles are generally nonstationary signals that contain significant transient events and are not well described in the spectral domain. The objective of this work, then, is to develop a method by which the characteristics of the road can be captured by describing these constitutive transient events.

Advances in avionics and display technology are significantly changing the cockpit environment in current transport aircraft. The MIT Aeronautical Systems Lab (ASL) has developed a part-task flight simulator specifically to study the effects of these new technologies on flight crew situational awareness and performance. The simulator is based on a commercially-available graphics workstation, and can be rapidly reconfigured to meet the varying demands of experimental studies. The simulator has been successfully used to evaluate graphical microburst alerting displays, electronic instrument approach plates, terrain awareness and alerting displays, and ATC routing amendment delivery through digital datalinks.

This paper describes a long-travel, greased-filled, torsional coupling for use in reducing driveline torsional vibration in vehicles equipped with Continuously Variable Transmissions (CVTs). Desired spring rate and damping of the coupling are determined by computer simulation of the vehicle driveline response during steady-state and transient modes of vehicle operation. Subsequent vehicle testing of prototype couplings show that temperature, grease volume, and seal damping are additional factors in the resulting coupling performance.

This paper describes a new grid generating system particularly designed for automobile external flow analyses. The system consists of three major parts as follows: Part I collects the geometrical data of the automobile surface and develops an intermediate grid. Part II generates the surface grid on the surface of the automobile. The surface grid is used as the boundary condition for generating the three-dimensional grid for the flow space. Part III generates the three-dimensional grid for external flow analyses. In generating the surface grid, a new approach of generating grid has been developed, in which two elliptic grid generation equations are solved directly on the physical domain. The three-dimensional grid is generated by the elliptic grid generation method blended with the hyperbolic method. An iterative solution algorithm based on the approximate factorization scheme has been developed.

The Comet Rendezvous Asteroid Flyby (CRAF) mission involves seven years of flight from 0.6 to 4.57 Astronomical Units (AU), followed by about 915 days of maneuvering around a comet. Ground testing will characterize the very critical attitude control system thrusters' fuel consumption and performance for all anticipated fuel temperatures over thruster life. The ground test program characterization will support flight condition monitoring. A commercial software application hosted on a commercial microcomputer will control ground test operations and data acquisition using a newly designed thrust stand. The data acquisition and control system uses a graphics-based language and features a visual interface to integrate data acquisition and control.

Computer-aided engineering (CAE) is an important tool routinely used to simulate complex engineering systems. Virtual simulations enhance engineering insight into prospective designs and potential design issues and can limit the need for expensive engineering prototypes. For complex engineering systems, however, the effectiveness of virtual simulations is often hindered by excessive computational cost. To minimize the cost of running expensive computer simulations, approximate models of the original model (often called surrogate models or metamodels) can provide sufficient accuracy at a lower computing overhead compared to repeated runs of a full simulation. Metamodel accuracy improves if constructed using space-filling designs of experiments (DOEs). The latter provide a collection of sample points in the design space preferably covering the entire space.

High-temperature sintering can cause loss of activity in the catalyst of an automotive emission control system. The elevated temperature required to sinter the catalyst could arise from a combination of a warmed-up converter plus unusually high engine-out carbon monoxide or unburned hydrocarbon “fuel.” This unburned “fuel” could result from sustained engine misfiring due to faulty ignition or from a prolonged high-speed, closed-throttle coast. Such abnormal “fuel” input to the converter has been prevented in all 1975 General Motors production vehicles by using the more reliable High Energy Ignition system and by properly controlling engine operating parameters during a closed-throttle coast. During the Corporate-wide program to develop systems to limit catalytic converter temperature, a “guard” converter system was evaluated as one of many candidate solutions.

Lots of invalid volume of traffic occurs as the vehicle repeatedly seeking the valid berth location, due to the existence of information islands, which reduces traffic efficiency, increases traffic congestion and the emission of pollutants. Aiming at eliminating the existence of information islands, this paper proposed a guidance strategy for parking space of autonomous valet parking, as taking merits of cooperative vehicle infrastructure system. The guidance strategy consists of an optimal guidance model and an adaptive ant-colony algorithm. Firstly, the optimal guidance model takes the minimum total parking cost as the objective function and the capacity of parking space as the constraints. Both the objective costs of parking and the subjective cost of customer are taken into accounts in the objective function.

This SAE Aerospace Information Report (AIR) is devoted to the challenges of applying optics to new advanced RF analog systems only; digital data link applications are covered elsewhere in protocol/architecture specific documents like Fibre Channel, ATM, Ethernet, Sonet, etc.

The installation of a power plant in a truck carries with it a requirement for attention to the systems which provide the operational support for the power plant. This paper addresses these systems by describing and discussing the designs that are commonly used and some of the pitfalls that may be encountered. These support systems are covered: engine mounting, cooling, drive train, air intake, fuel, lubrication, exhaust, and accessories. Also discussed are clearances between the engine and adjacent surfaces and truck noise levels.

Consideration for the damaging effects to aircraft from the failure of wheels and tires should be evaluated. This document discusses the types of problems in-service aircraft have experienced and methodology in place to assist the designers when evaluating threats for new aircraft design. The purpose of this document is to provide a history of in-service problems, provide a historical summary of the design improvements made to wheels and tires during the past 40 years and to offer methodology which has been used to help designers assess the threat to ensure the functionality of systems and equipment located in and around the landing gear and in wheel wells.

Consideration for the damaging effects to aircraft from the failure of wheels and tires should be evaluated. This document discusses the types of problems in-service aircraft have experienced and methodology in place to assist the designers when evaluating threats for new aircraft design. The purpose of this document is to provide a history of in-service problems, provide a historical summary of the design improvements made to wheels and tires during the past 40 years, and to offer methodology which has been used to help designers assess the threat to ensure the functionality of systems and equipment located in and around the landing gear and in wheel wells.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: a Functional considerations. b Weight considerations. c Environmental performance factors. d End fitting types. e Additional considerations. A quick-disconnect coupling as used in this AIR is one that can be rapidly and repetitively connected and disconnected without excessive fluid loss. The relative importance of the design factors depends upon the fluid medium of the particular system in which quick-disconnect is to be used. The effect of the fluid media on each factor is discussed in this report where applicable.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: a Functional considerations. b Weight considerations. c Environmental performance factors. d End fitting types. e Additional considerations. A quick-disconnect coupling as used in this AIR is one that can be rapidly and repetitively connected and disconnected without excessive fluid loss. The relative importance of the design factors depends upon the fluid medium of the particular system in which quick-disconnect is to be used. The effect of the fluid media on each factor is discussed in this report where applicable.

Based on their viscoelastic properties, the temperature of plastic structural members under oscillatory loads rises during the loading time. For the case that this temperature reaches a constant value, i. e. an equilibrium between the supplied and the delivered heat is established, the temperature rise can be calculated in the presented manner. Below the critical strain limit, the behaviour of the self-heated material is similar to its behaviour at corresponding increased environmental temperature. With the knowledge of this facts, the consideration of the self - heating of plastics is easily possible.

AIR5317 establishes the foundation for developing a successful APU health management capability for any commercial or military operator, flying fixed wing aircraft or rotorcraft. This AIR provides guidance for demonstrating business value through improved dispatch reliability, fewer service interruptions, and lower maintenance costs and for satisfying Extended Operations (ETOPS) availability and compliance requirements.

The SAE Guide to APU health management establishes the foundation for developing a successful APU health management program at any aircraft or APU operator, such as an airline, an OEM, an equipment supplier, or a military transport unit. This guide identifies the best practices for using an APU health management program to improve dispatch reliability and to satisfy Extended Operations (ETOPS) availability requirements.

The purpose of this SAE Aerospace Information Report (AIR) is to provide management, designers, and operators with information to assist them to decide what type of power train monitoring they desire. This document is to provide assistance in optimizing system complexity, performance and cost effectiveness. This document covers all power train elements from the point at which the gas generator energy is transferred to mechanical energy for propulsion purposes. The document covers engine power train components, their interfaces, transmissions, gearboxes, hanger bearings, shafting and associated rotating accessories, propellers and rotor systems as shown in Figure 1. This document addresses application for rotorcraft, turboprop, and propfan drive trains for both commercial and military aircraft. Information is provided to assist in; a. Defining technology maturity and application risk b. Cost benefit analysis (Value analysis) c. Selection of system components d.