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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 901 records · Page 50

MOSS, an evaluation of software engineering techniques

An evaluation of the software engineering techniques used for the development of a Modular Operating System (MOSS) was described. MOSS is a general purpose real time operating system which was developed for the Concept Verification Test (CVT) program. Each of the software engineering techniques was described and evaluated based on the experience of the MOSS project. Recommendations for the use of these techniques on future software projects were also given.

Bounds, J. R.↗

Development of a high temperature static strain sensor

The goal of this program is to develop an electrical resistance strain gage system which will accurately measure the static strains of superalloy blades and vanes in gas turbine engines running on a test stand. Accurate knowledge of these strains is essential to reaching the goals of the HOST program in the selection and experimental verification of the various theoretical models developed to understand and improve the performance of these engines. The specific objective is to develop a complete system capable of making strain measurements of up to + or - 10 percent of full scale during a 50 hour period at temperatures as high as 1250 K. In addition to survival and stability, attaining a low temperature coefficient of resistance, of the order of 20 ppm/K or less, was a major goal. This requirement arises from the presently unavoidable uncertainties in measurement of the exact temperatures inside gas turbines for use in making corrections for apparent strain due to temperature.

Hulse, Charles O.↗

Should we attempt global (inlet engine airframe) control design?

The feasibility of multivariable design of the entire airplane control system is briefly addressed. An intermediate step in that direction is to design a control for an inlet engine augmentor system by using multivariable techniques. The supersonic cruise large scale inlet research program is described which will provide an opportunity to develop, integrate, and wind tunnel test a control for a mixed compression inlet and variable cycle engine. The integrated propulsion airframe control program is also discussed which will introduce the problem of implementing MVC within a distributed processing avionics architecture, requiring real time decomposition of the global design into independent modules in response to hardware communication failures.

Carlin, C. M.↗

Integrated Flight Propulsion Control Research Results Using the NASA F-15 HIDEC Flight Research Facility

Over the last two decades, NASA has conducted several flight research experiments in integrated flight-propulsion control. Benefits have included increased thrust, range, and survivability; reduced fuel consumption; and reduced maintenance. These flight programs were flown at NASA Dryden Flight Research Facility. This paper presents the basic concepts for control integration, examples of implementation, and benefits of integrated flight propulsion control systems. The F-15 research involved integration of the engine, flight, and inlet control systems. Further extension of the integration included real-time, onboard optimization of engine, inlet, and flight control variables; a self-repairing flight control system; and an engines-only control concept for emergency control. The flight research programs and the resulting benefits are described for the F-15 research.

Flight Testing↗

Energy Efficient Engine Flight Propulsion System Preliminary Analysis and Design Report

The final design and analysis of the flight propulsion system is presented. This system is the conceptual study engine defined to meet the performance, economic and environmental goals established for the Energy Efficient Engine Program. The design effort included a final definition of the engine, major components, internal subsystems, and nacelle. Various analytical representations and results from component technology programs are used to verify aerodynamic and structural design concepts and to predict performance. Specific design goals and specifications, reflecting future commercial aircraft propulsion system requirements for the mid-1980's, are detailed by NASA and used as guidelines during engine definition. Information is also included which details salient results from a separate study to define a turbofan propulsion system, known as the maximum efficiency engine, which reoptimized the advanced fuel saving technologies for improved fuel economy and direct operating costs relative to the flight propulsion system.

Bisset, J. W.↗

HiRel: Hybrid Automated Reliability Predictor (HARP) integrated reliability tool system, (version 7.0). Volume 3: HARP Graphics Oriented (GO) input user's guide

The Hybrid Automated Reliability Predictor (HARP) integrated Reliability (HiRel) tool system for reliability/availability prediction offers a toolbox of integrated reliability/availability programs that can be used to customize the user's application in a workstation or nonworkstation environment. HiRel consists of interactive graphical input/output programs and four reliability/availability modeling engines that provide analytical and simulative solutions to a wide host of highly reliable fault-tolerant system architectures and is also applicable to electronic systems in general. The tool system was designed at the outset to be compatible with most computing platforms and operating systems, and some programs have been beta tested within the aerospace community for over 8 years. This document is a user's guide for the HiRel graphical preprocessor Graphics Oriented (GO) program. GO is a graphical user interface for the HARP engine that enables the drawing of reliability/availability models on a monitor. A mouse is used to select fault tree gates or Markov graphical symbols from a menu for drawing.

Bavuso, Salvatore J.↗

Advanced space engine component technology status

Key to the achievement of maximum benefit from the Space Tug transportation system is the availability of a low-cost, high-performance engine system. To define this engine system, studies have been conducted under Air Force and NASA direction, and pertinent hardware technology programs have been initiated. From among the several candidate systems studied, the cryogenic, staged-combustion cycle, high chamber pressure system in conjunction with a large-area-ratio nozzle was selected for component and subsystem demonstration. Main turbopump, high-area-ratio thrust chamber, preburner, and igniter components are being evaluated. A brief description of the engine capabilities, the main liquid hydrogen and liquid oxygen turbopump/preburner, and the main thrust chamber programs are presented; designs and progress in fabrication are shown and test results discussed.

Zachary, A. T.↗

On-Board Chemical Propulsion

NASA Lewis Research Center's On-Board Propulsion program (OBP) is developing low-thrust chemical propulsion technologies for both satellite and vehicle reaction control applications. There is a vigorous international competition to develop new, highperformance bipropellant engines. High-leverage bipropellant systems are critical to both commercial competitiveness in the international communications market and to cost-effective mission design in government sectors. To significantly improve bipropellant engine performance, we must increase the thermal margin of the chamber materials. Iridium-coated rhenium (Ir/Re) engines, developed and demonstrated under OBP programs, can operate at temperatures well above the constraints of state-of-practice systems, providing a sufficient margin to maximize performance with the hypergolic propellants used in most satellite propulsion systems.

Schneider, Steven J.↗

The DLG processor: A data management executive for the engineering design integration (EDIN) system. Volume 1: Engineering description and utilization manual

The DLG processor is a Univac 1100 series computer program designed to read, modify, manipulate, and replace symbolic images. DLG is controlled by a set of user supplied directives and operates from a data base of stratified information which can be merged with the symbolic images. Data bases can be constructed and maintained in the mass storage media using the DLG directive language.

Glatt, C. R.↗

Ceramic regenerator systems development program

Ceramic regenerator cores are considered that can be used in passenger car gas turbine engines, Stirling engines, and industrial/truck gas turbine engines. Improved materials and design concepts aimed at reducing or eliminating chemical attack were placed on durability test in Ford 707 industrial gas turbine engines. The results of 19,600 hours of turbine engine durability testing are described. Two materials, aluminum silicate and magnesium aluminum silicate, continue to show promise toward achieving the durability objectives of this program. A regenerator core made from aluminum silicate showed minimal evidence of chemical attack damage after 6935 hours of engine test at 800 C and another showed little distress after 3510 hours at 982 C. Results obtained in ceramic material screening tests, aerothermodynamic performance tests, stress analysis, cost studies, and material specifications are also included.

Cook, J. A.↗

Ceramic regenerator systems development program

Ceramic regenerator cores are considered that can be used in passenger car gas turbine engines, Stirling engines, and industrial/truck gas turbine engines. Improved materials and design concepts aimed at reducing or eliminating chemical attack were placed on durability tests/in industrial gas turbine engines. A regenerator core made from aluminum silicate shows minimal evidence of chemical attack damage after 7804 hours of engine test at 800 C and another showed little distress after 4983 hours at 982 C. The results obtained in ceramic material screening tests, aerothermodynamic performance tests, stress analysis, cost studies, and material specifications are also included.

Cook, J. A.↗

The Environment-Power System Analysis Tool development program

The Environment Power System Analysis Tool (EPSAT) is being developed to provide engineers with the ability to assess the effects of a broad range of environmental interactions on space power systems. A unique user-interface-data-dictionary code architecture oversees a collection of existing and future environmental modeling codes (e.g., neutral density) and physical interaction models (e.g., sheath ionization). The user-interface presents the engineer with tables, graphs, and plots which, under supervision of the data dictionary, are automatically updated in response to parameter change. EPSAT thus provides the engineer with a comprehensive and responsive environmental assessment tool and the scientist with a framework into which new environmental or physical models can be easily incorporated.

Jongeward, Gary A.↗

SSSFD manipulator engineering using statistical experiment design techniques

The Satellite Servicer System Flight Demonstration (SSSFD) program is a series of Shuttle flights designed to verify major on-orbit satellite servicing capabilities, such as rendezvous and docking of free flyers, Orbital Replacement Unit (ORU) exchange, and fluid transfer. A major part of this system is the manipulator system that will perform the ORU exchange. The manipulator must possess adequate toolplate dexterity to maneuver a variety of EVA-type tools into position to interface with ORU fasteners, connectors, latches, and handles on the satellite, and to move workpieces and ORUs through 6 degree of freedom (dof) space from the Target Vehicle (TV) to the Support Module (SM) and back. Two cost efficient tools were combined to perform a study of robot manipulator design parameters. These tools are graphical computer simulations and Taguchi Design of Experiment methods. Using a graphics platform, an off-the-shelf robot simulation software package, and an experiment designed with Taguchi's approach, the sensitivities of various manipulator kinematic design parameters to performance characteristics are determined with minimal cost.

Barnes, John↗

Formal Inspection: A Tool for TQM

The goal of the Formal Inspection Program at the Jet Propulsion Laboratory (JPL) is to support projects wishing to use Formal Inspections to improve the quality of software and system level engineering products.

errors total quality↗

Flight evaluation results for a digital electronic engine control in an F-15 airplane

A digital electronic engine control (DEEC) system on an F100 engine in an F-15 airplane was evaluated in flight. Thirty flights were flown in a four-phase program from June 1981 to February 1983. Significant improvements in the operability and performance of the F100 engine were developed as a result of the flight evaluation: the augmentor envelope was increased by 15,000 ft, the airstart envelope was improved by 75 knots, and the need to periodically trim the engine was eliminated. The hydromechanical backup control performance was evaluated and was found to be satisfactory. Two system failures were encountered in the test program; both were detected and accommodated successfully. No transfers to the backup control system were required, and no automatic transfers occurred. As a result of the successful DEEC flight evaluation, the DEEC system has entered the full-scale development phase.

Burcham, F. W., Jr.↗

Computer-Aided Engineering Of Cabling

Program generates data sheets, drawings, and other information on electrical connections. DFACS program, centered around single data base, has built-in menus providing easy input of, and access to, data for all personnel involved in system, subsystem, and cabling. Enables parallel design of circuit-data sheets and drawings of harnesses. Also recombines raw information to generate automatically various project documents and drawings, including index of circuit-data sheets, list of electrical-interface circuits, lists of assemblies and equipment, cabling trees, and drawings of cabling electrical interfaces and harnesses. Purpose of program to provide engineering community with centralized data base for putting in, and gaining access to, functional definition of system as specified in terms of details of pin connections of end circuits of subsystems and instruments and data on harnessing. Primary objective to provide instantaneous single point of interchange of information, thus avoiding

Billitti, Joseph W.↗

Ada and the rapid development lifecycle

JPL is under contract, through NASA, with the US Army to develop a state-of-the-art Command Center System for the US European Command (USEUCOM). The Command Center System will receive, process, and integrate force status information from various sources and provide this integrated information to staff officers and decision makers in a format designed to enhance user comprehension and utility. The system is based on distributed workstation class microcomputers, VAX- and SUN-based data servers, and interfaces to existing military mainframe systems and communication networks. JPL is developing the Command Center System utilizing an incremental delivery methodology called the Rapid Development Methodology with adherence to government and industry standards including the UNIX operating system, X Windows, OSF/Motif, and the Ada programming language. Through a combination of software engineering techniques specific to the Ada programming language and the Rapid Development Approach, JPL was able to deliver capability to the military user incrementally, with comparable quality and improved economies of projects developed under more traditional software intensive system implementation methodologies.

Deforrest, Lloyd↗