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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Pressure and force data for a flat wing and a warped conical wing having a shockless recompression at Mach 1.62

A conical nonlinear flow computer code was used to design a warped (cambered) wing which would produce a supercritical expansion and shockless recompression of the crossflow at a lift coefficient of 0.457, an angle of attack of 10 deg, and a Mach number of 1.62. This cambered wing and a flat wing the same thickness distribution were tested over a range of Mach numbers from 1.6 to 2.0. For both models the forward 60 percent is purely conical geometry. Results obtained with the cambered wing demonstrated the design features of a supercritical expansion and a shockless recompression, whereas results obtained with the flat wing indicated the presence of crossflow shocks. Tables of experimental pressure, force, and moment data are included, as well as selected oil flow photographs.

Miller, D. S.↗
NASA NTRS1981

Latch mechanism for the space telescope

Latch mechanisms to secure, release, and relatch deployables on the Space Telescope are described. The latch mechanisms are mechanical pre-loading devices composed of a four-bar linkage driven by an electro-mechanical rotary actuator. The latch mechanism requirements, unique design features, analytical highlights, and the development testing are discussed.

Schmidt, H. F.↗
NASA NTRS1981

Fresnel concentrating collector

An advanced point focusing solar technology demonstrated potential for near term commercialization as a renewable energy technology. The design features combine to produce a highly efficient, low cost, safe, adaptable, durable system which is simple to manufacture, install and maintain.

Rogers, W.↗
NASA NTRS1980

SPS design with solid-state transmitter

The replacement of the klystrons in the microwave transmitter in the SPS leads to major redesign considerations. Several curves are presented which show the interrelations of the major design features, the power level and the transmitting and receiving dimensions.

Ettenberg, M.↗
NASA NTRS1981

Development of a low NO/x/ lean premixed annular combustor

The results of an experimental atmospheric rig test program developed to define a low NO(x) annular combustor of 0.66 m diameter for high-altitude aircraft applications are presented. The test program strategy adopted evaluates the emission characteristics of a baseline configuration and subsequently examines the sensitivity of the emission signatures to variations in the key design features. The lean premixed combustor in axisymmetric annular form demonstrates the capability of operating at reduced-pressure, simulated high-altitude, supersonic cruise conditions with NO(x) emissions below 1.0 g NO2/kg fuel. The testing shows that for the full range of low emissions operation from idle to cruise, a variable dilution port system is necessary, but that fuel-switching can be avoided and a single fuel injection system used.

Roberts, P. B.↗
NASA NTRS1979

Development of the coastal zone color scanner for NIMBUS 7. Volume 1: Mission objectives and instrument description

An Earth scanning six channel (detector) radiometer using a classical Cassegrain telescope and a Wadsworth type grating spectrometer was launched aboard Nimbus 7 in order to determine the abundance or density of chlorophyll at or near the sea surface in coastal waters. The instrument also measures the sediment or gelbstroffe (yellow stuff) in coastal waters, detects surface vegetation, and measures sea surface temperature. Block diagrams and schematics are presented, design features are discussed and each subsystem of the instrument is described. A mission overview is included.

Source record↗
NASA NTRS1981

A cloud condensation nucleus spectrometer designed for airborne measurements

The spectrometer is a simple extension of the continuous flow diffusion chamber (CFDC) operated in the vertical mode. The principal new design features of the instrument are its rapid time response and ability to rapidly measure the CCN activity spectrum. The activity spectrum of CCN in an air sample is measured by simultaneously operating the spectrometer at four supersaturations. The CCN spectrometer consists of four essentially indepenent CFDC's in a parallel array. Each CFDC is 61 cm long, 10 cm wide, and consists of two vertical parallel plates 1 cm apart, maintained at different temperatures. Each CFDC has a single particle optical counter located at the center of its base.

Radke, L. F.↗
NASA NTRS1981

Conventional engine technology. Volume 2: Status of diesel engine technology

The engines of diesel cars marketed in the United States were examined. Prominent design features, performance characteristics, fuel economy and emissions data were compared. Specific problems, in particular those of NO and smoke emissions, the effects of increasing dieselization on diesel fuel price and availability, current R&D work and advanced diesel concepts are discussed. Diesel cars currently have a fuel economy advantage over gasoline engine powered cars. Diesel drawbacks (noise and odor) were reduced to a less objectionable level. An equivalent gasoline engine driveability was obtained with turbocharging. Diesel manufacturers see a growth in the diesel market for the next ten years. Uncertainties regarding future emission regulation may inhibit future diesel production investments. With spark ignition engine technology advancing in the direction of high compression ratios, the fuel economy advantages of the diesel car is expected to diminish. To return its fuel economy lead, the diesel's potential for future improvement must be used.

Schneider, H. W.↗
NASA NTRS1982

A rubidium clock for GPS

The design objectives and approach; the more important design features; the signal parameters and error budget; and early test results in the development of a second-source rubidium frequency standard for use in the GPS navigation satellites are discussed. Tests of a breadboard version of the RFS show that the measured time-domain stability is within the goal specification. The results are uncorrected for the conribution of the reference and are probably limited by the reference stability in the medium term region. The Rb reference is bbetter in the medium term region, but the Cs reference is etter at 10,000 seconds and longer, probably because of the barometric sensitivity of the rubidium reference unit.

Riley, W. J.↗
NASA NTRS1981

Study of Advanced Propulsion Systems for Small Transport Aircraft Technology (STAT) Program

Definitions of takeoff gross weight, performance, and direct operating cost for both a 30 and 50 passenger airplane were established. The results indicate that a potential direct operating cost benefit, resulting from advanced technologies, of approximately 20 percent would be achieved for the 1990 engines. Of the numerous design features that were evaluated, only maintenance-related items contributed to a significant decrease in direct operating cost. Recommendations are made to continue research and technology programs for advanced component and engine development.

Baerst, C. F.↗
NASA NTRS1979

Air Brayton Solar Receiver, phase 1

A six month analysis and conceptual design study of an open cycle Air Brayton Solar Receiver (ABSR) for use on a tracking, parabolic solar concentrator are discussed. The ABSR, which includes a buffer storage system, is designed to provide inlet air to a power conversion unit. Parametric analyses, conceptual design, interface requirements, and production cost estimates are described. The design features were optimized to yield a zero maintenance, low cost, high efficiency concept that will provide a 30 year operational life.

Zimmerman, D. K.↗
NASA NTRS1982

The Space Telescope Observatory

The history of the observatory is briefly described, as is the overall system design. The principal design features that are important to the scientific user are described. The present status of preparation for launch in the spring of 1985 is summarized.

Odell, C. R.↗
NASA NTRS1981

Advanced 30/20 GHz communication satellites

Increasing demands for satellite communications channels have filled the C-band, have begun to fill the Ku-band, and have resulted in a developmental effort to utilize 2.5 GHz of the 30/20 GHz Ka band. Problems of rain attenuation in the Ku and Ka bands are explored, and solutions are indicated in the use of antenna gain coupled with ground terminal site diversity, and higher satellite power capabilities. Tradeoffs in satellite design are focused on the number of reflectors, increased f/d, gain and sidelobe performance, and total satellite capacity. The NASA 20/30 GHz program is described, including design features of two test systems to be launched in the 1980's to examine the functioning limits of two baseline systems.

Sivo, J. N.↗
NASA NTRS1981

Postflight analysis of the Space Shuttle ascent air data system

An analysis of measurements recorded by the ascent air data system (AADS) located on the nose of the external tank of the Shuttle during the first flight is presented. The 30/10 deg biconic spike has five pressure ports for tracking yaw and pitch attitude, total pressure, and static pressure; comparison of AADS data with wind tunnel data allowed determination of angle of attack, angle of sideslip, Mach number, and dynamic pressure. Program goals for AADS development are reviewed, and specific design features are described. Wind tunnel test data were compared with best estimates simulations and initial flight data where possible; only wind tunnel derived Mach number predictions for time intervals 90 sec after launch are noted to deviate significantly from actual flight data.

Hillje, E. R.↗
NASA NTRS1982

Aerothermodynamic entry environment of the Space Shuttle Orbiter

The entry aerothermodynamic environment for the Space Shuttle vehicle was an important factor in the design of the Orbiter. A design goal established during the initial study phase of the Shuttle program was to minimize the thermal protection system's weight. A description is presented of the design approach and preliminary flight test results relative to the entry heating environment for the complex flowfield regions of the Space Shuttle Orbiter. Attention is given to Orbiter aerothermodynamic design features, aspects of trajectory development, the wind tunnel test program, heating environments, boundary-layer transition problems, and the flight test program.

Lee, D. B.↗
NASA NTRS1982

NASA/General Electric broad-specification fuels combustion technology program - Phase I results and status

A program is being conducted to develop the technology required to utilize fuels with broadened properties in aircraft gas turbine engines. The first phase of this program consisted of the experimental evaluation of three different combustor concepts to determine their potential for meeting several specific emissions and performance goals, when operated on broadened property fuels. The three concepts were a single annular combustor; a double annular combustor; and a short single annular combustor with variable geometry. All of these concepts were sized for the General Electric CF6-80 engine. A total of 24 different configurations of these concepts were evaluated in a high pressure test facility, using four test fuels having hydrogen contents between 11.8 and 14%. Fuel effects on combustor performance, durability and emissions, and combustor design features to offset these effects were demonstrated.

Dodds, W. J.↗
NASA NTRS1982

Progress in the development of energy efficient engine components

Component test results are presented for the NASA Energy Efficient Engine program, whose design goals relative to the CF6-50C reference engine include a 12% reduction in specific fuel consumption, 5% reduction in direct operating costs, and 50% reduction in specific fuel consumption deterioration rate over the course of commercial service. Emphasis is placed on the engine's high pressure compressor, which has a design pressure ratio of 23:1, and has completed a series of component tests whose resulting configuration is expected to meet all major objectives of the program. Descriptions are given of the core engine and integrated core/low spool tests, and system test benefits are discussed. Attention is given to the design features of the engine's double annular combustor, high and low pressure air turbines, and scale model exhaust mixer.

Bucy, R. W.↗
NASA NTRS1982

A miniature electro-optical air flow sensor

Miniature sensors are needed for rapid and uncomplicated installation on light aircraft engaged in stability research programs. One particularly difficult sensor to miniaturize to the required degree has been a flow angle and velocity sensor for measuring the local flow ahead of a wing. However, by using an electrooptical technique it was possible to overcome the encountered difficulties and to design a sensor satisfying the requirements. The developed sensor for measuring angle-of-attack, yaw, and airspeed was shown to be suitable for rapid instrumentation of research aircraft because of its small size. The size reduction was accomplished by a design feature which eliminates the need for slip rings and wiring within the movable components of the sensor.

Kershner, D. D.↗