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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Aerospace mechanical reliability practice

The impact of mechanical-reliability practice on the Saturn/Apollo launch program is considered with reference to the interrelationship of analysts and designers with management. Rocket engine development, ground testing, and launch facilities in the Saturn/Apollo program are discussed, and the Saturn reliability approach is examined in regard to management style, decision making, human error control, and reliability analyses. It is noted that the use of conservative design philosophy contributed to achieved reliability.

Fedor, O. H.↗
NASA NTRS1982

Teleoperator maneuvering system

The teleoperator maneuvering system (TMS), consisting of the vehicle, the shuttle orbiter bay cradle with airborne support equipment, and the aft flight deck control station, is described. The vehicle is a reusable remotely controlled free flying vehicle capable of a variety of missions including payload placement, retrieval, servicing, viewing, and large space systems assembly support. The TMS flies preprogrammed trajectories as well as being controlled or reprogrammed from the aft flight deck or the ground. A building block design philosophy is described which permits the evolution of capability as it is needed and delays cost as much as possible. Various mission operations are discussed.

Turner, J. R.↗
NASA NTRS1983

Hinge latch mechanism

The device described in this paper is a modular hinge latch mechanism. It is used to latch and preload four motorized hinges after their deployment. The paper describes design requirements, hardware development and initial testing of this hinge latch module. A special effort has been made to cover the design philosophy incorporated into this hardware.

Walker, J. C.↗
NASA NTRS1984

Fuel property effects on USN gas turbine combustors

For several years the Department of Defense has been sponsoring fuel accommodation investigations with gas turbine engine manufacturers and supporting organizations to quantify the effect of changes in fuel properties and characteristics on the operation and performance of military engine components and systems. Inasmuch as there are many differences in hardware between the operational engines in the military inventories, due to differences in design philosophy and requirements, efforts were initially expended to acquire fuel effects data from rigs simulating the hot sections of these different engines. Correlations were then sought using the data acquired to produce more general, generic relationships that could be applied to all military gas turbine engines regardless of their origin. Finally, models could be developed from these correlations that could predict the effect of fuel property changes on current and future engines. This presentation describes some of the work performed by Pratt and Whitney Aircraft, under Naval Air Propulsion Center sponsorship, to determine the effect of fuel properties on the hot section and fuel system of the Navy's TF30-P-414 gas turbine engine.

Masters, A. I.↗
NASA NTRS1984

White Cliffs: Operating Experience

The fourteen dish white cliffs solar power station area is remote and subject to extreme environmental conditions, solution of the associated problems required careful and thoughtful attention and the application of resources. Notwithstanding the wide range and harshness of conditions, the difficulties caused by remoteness and the lack of a technological base and the need for relatively rapid demonstration of success, the project has had a very positive outcome. Qualitative and quantitative information and lessons are now available to enable considerable simplifications to be made for a new system, reducing both hardware and operation and maintenance costs. Experience and lessons are presented, particularly in relation to: system performance in various environmental conditions; design philosophies for collectors, the array, control systems, engine and plant; operation and maintenance strategies and cost reducing possibilities. Experience so far gives encouragement for the future of such paraboloidal dish systems in appropriate areas.

Kaneff, S.↗
NASA NTRS1984

The Base Engine for Solar Stirling Power

A new concept in Stirling engine technology is embodied in the base engine now being developed at Stirling Thermal Motors, Inc. This is a versatile energy conversion unit suitable for many different applications and heat sources. The base engine, rated 40 kW at 2800 RPM, is a four-cylinder, double-acting variable displacement Stirling engine with pressurized crankcase and rotating shaft seal. Remote-heating technology is incorporated with a stacked-heat-exchanger configuration and a liquid metal heat pipe connected to a distinctly separate combustor or other heat source. High efficiency over a wide range of operating conditions, long life, low manufacturing cost and low material cost are specifically emphasized. The base engine, its design philosophy and approach, its projected performance, and some of its more attractive applications are described.

Meijer, R. J.↗
NASA NTRS1984

Electrochemical storage

The source of the problem within the individual single cell which is related to the stochastic properties of cell populations and to the actual electrochemistry and chemistry taking place is described. The complications which arise in multicell batteries to show how different electrochemistries might alleviate or accentuate these problems is described. The concept of the electrochemical system is introduced to show how certain shortcomings of the single cell/battery string concept can be circumvented. Some of these electrochemical systems permit performance characteristics that are impossible by using conventional battery design philosophies. Projections for energy density and performance characteristics of the concepts are addressed.

Thaller, L. H.↗
NASA NTRS1983

Computers in the cockpit - But what about the pilots?

The advent of the microprocessor has made it possible to design and implement small special purpose digital computers for the flightdeck of an aircraft. However, by the end of the 1970s, many in aviation and government were concerned about certain safety implications of developments related to automation which had occurred. As a result of these concerns, NASA was directed to examine the human factors of automation. A field investigation concerning the arising questions was conducted, taking into account the introduction of the Dash 80 airliner in 1980. Attention is given to the design philosophy of the aircraft, the study methodology, and preliminary results of the study, which are based on analysis of the first wave of questionnaire data and interviews. Almost all pilots, and check captains as well, expressed the view that the first 50 to 100 hours in the -80 were difficult. The reasons for these difficulties were related to cockpit automation and, in addition, to the fact that the new aircraft was more powerful than the older models to which they were accustomed.

Wiener, E. L.↗
NASA NTRS1982

An application of distributed processing - In the TDRSS ground communication fault isolation and monitoring system

A computer interface has been designed for the Fault Isolation and Monitoring System, a system providing qualitative and quantitative assessment of the communications between the Tracking and Data Relay Satellite System Ground Segment and NASA's Network Control Center. The functional requirements for the interface and the design philosophy are discussed, as are the methods and protocol used to implement the operator support software required to configure the monitoring system and to display and report the results of the analysis. The system relies on the use of intelligent terminals, with the human interface removed from the host computer.

Waddell, R. L., Jr.↗
NASA NTRS1984

Spaceborne receivers: Basic principles

The underlying principles of operation of microwave receivers for space observations of planetary surfaces were examined. The design philosophy of the receiver as it is applied to operate functionally as an efficient receiving system, the principle of operation of the key components of the receiver, and the important differences among receiver types are explained. The operating performance and the sensitivity expectations for both the modulated and total power receiver configurations are outlined. The expressions are derived from first principles and are developed through the important intermediate stages to form practicle and easily applied equations. The transfer of thermodynamic energy from point to point within the receiver is illustrated. The language of microwave receivers is applied statistics.

Stacey, J. M.↗
NASA NTRS1985

Space station trace contaminant control

Different systems for the control of space station trace contaminants are outlined. The issues discussed include: spacecabin contaminant sources, technology base, contaminant control system elements and configuration, approach to contaminant control, contaminant load model definition, spacecraft maximum allowable concentrations, charcoal bed sizing and performance characteristics, catalytic oxidizer sizing and performance characteristics, special sorbent bed sizing, animal and plant research payload problems, and emergency upset contaminant removal. It is concluded that the trace contaminant control technology base is firm, the necessary hardware tools are available, and the previous design philosophy is still applicable. Some concerns are the need as opposed to danger of the catalytic oxidizer, contaminants with very low allowable concentrations, and the impact of relaxing materials requirements.

Olcutt, T.↗
NASA NTRS1985

Ultrareliable, fault-tolerant control systems: A conceptual description

An Ultrareliable, Fault-Tolerant, Control-System (UFTCS) concept is described using a systems design philosophy which allows development of system structures containing virtually no common elements. Common elements limit achievable system reliability and can cause catastrophic loss of fault-tolerant system function. The UFTCS concept provides the means for removing common system elements by permitting the elements of the system to operate as independent, uncoupled entities. Multiple versions of the application program are run on dissimilar hardware. Fault tolerance is achieved through the use of static redundancy management.

Webster, L. D.↗
NASA NTRS1985

The University of Durham Mark 3 very high energy gamma ray telescope

A new very high energy gamma-ray telescope employing the atmospheric Cerenkov light technique and currently nearing completion is described. The telescope is designed to have capability as both a wide angle instrument (4 degree field of view) for sky survey work and as a narrow field of view instrument (1.35 degrees) for conventional drift-scanning and tracking modes of operation. The telescope consists of two 10 sq. m. mirrors operated in fast coincidence with multiple phototube assemblies at the prime focus of each mirror. The design philosophy of the instrument is discussed and comparisons of its performance with our previous telescopes are made.

Chadwick, P. M.↗
NASA NTRS1986

PCDS overview

A brief overview of the philosophy, design, and organization of the Pilot Climate Data System (PCDS) is presented. The design has evolved, over time, to deal with numerous data sets, provide appropriate tools for the manipulation and display of such data, and support a wide variety of users. The user interface to the system is provided by the Transportable Applications Executive (TAE). A user can choose one of the five major subsystems from the root menu display. These subsystems are CATALOG, INVENTORY, DATA ACCESS, DATA MANIPULATION, and GRAPHICS. Each subsystem was discussed and examples were given, demonstrating the flexibility provided by the existing PCDS software, Version 3.3. Three of these subsystems are presently being redesigned to provide a more flexible and friendly structure, to allow more consistency and facilitate the ability to support new data sets. Ongoing developmental efforts to migrate from the Version 3.3 prototype phase of PCDS to the operational Version 4.0 stress increased flexibility and data independence.

Treinish, L.↗
NASA NTRS1986

Experience with synchronous and asynchronous digital control systems

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

Regenie, V. A.↗
NASA NTRS1986

Survey of supersonic combustion ramjet research at Langley

The Hypersonic Propulsion Branch at NASA Langley Research Center has maintained an active research program in supersonic combustion ramjet (scramjet) and high speed ramjet propulsion since the 1960s. The focus for this research has centered on propulsion for manned reuseable vehicles with cryogenic hydrogen fuel. This paper presents some highlights of this research. The design philosophy of the Langley fixed-geometry airframe-integrated modular scramjet is discussed. The component development and research programs that have supported the successful demonstration of the engine concept using subscale engine module hardware is reviewed and a brief summary of the engine tests presented. An extensive bibliography of research supported by the Langley program is also included.

Northam, G. B.↗
NASA NTRS1985

An investigation of the effects of the propeller slipstream of a laminar wing boundary layer

A research program is in progress to study the effects of the propeller slipstream on natural laminar flow. Flight and wind tunnel measurements of the wing boundary layer have been made using hot-film velocity sensor probes. The results show the boundary layer, at any given point, to alternate between laminar and turbulent states. This cyclic behavior is due to periodic external flow turbulence originating from the viscous wake of the propeller blades. Analytic studies show the cyclic laminar/turbulent boundary layer to result in a significantly lower wing section drag than a fully turbulent boundary layer. The application of natural laminar flow design philosophy yields drag reduction benefits in the slipstream affected regions of the airframe, as well as the unaffected regions.

Howard, R. M.↗
NASA NTRS1986

Experience with synchronous and asynchronous digital control systems

Flight control systems have undergone a revolution since the days of simple mechanical linkages; presently the most advanced systems are full-authority, full-time digital systems controlling unstable aircraft. With the use of advanced control systems, the aerodynamic design can incorporate features that allow greater performance and fuel savings, as can be seen on the new Airbus design and advanced tactical fighter concepts. These advanced aircraft will be and are relying on the flight control system to provide the stability and handling qualities required for safe flight and to allow the pilot to control the aircraft. Various design philosophies have been proposed and followed to investigate system architectures for these advanced flight control systems. One major area of discussion is whether a multichannel digital control system should be synchronous or asynchronous. This paper addressed the flight experience at the Dryden Flight Research Facility of NASA's Ames Research Center with both synchronous and asynchronous digital flight control systems. Four different flight control systems are evaluated against criteria such as software reliability, cost increases, and schedule delays.

Regenie, Victoria A.↗