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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 1,261 records · Page 70
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

M-DAS: System for multispectral data analysis

M-DAS is a ground data processing system designed for analysis of multispectral data. M-DAS operates on multispectral data from LANDSAT, S-192, M2S and other sources in CCT form. Interactive training by operator-investigators using a variable cursor on a color display was used to derive optimum processing coefficients and data on cluster separability. An advanced multivariate normal-maximum likelihood processing algorithm was used to produce output in various formats: color-coded film images, geometrically corrected map overlays, moving displays of scene sections, coverage tabulations and categorized CCTs. The analysis procedure for M-DAS involves three phases: (1) screening and training, (2) analysis of training data to compute performance predictions and processing coefficients, and (3) processing of multichannel input data into categorized results. Typical M-DAS applications involve iteration between each of these phases. A series of photographs of the M-DAS display are used to illustrate M-DAS operation.

Johnson, R. H.↗
NASA NTRS1975

Design, fabrication, and test of a graphite/epoxy metering truss

A graphite/epoxy metering truss as applied to the large space telescope was investigated. A full-scale truss was designed, fabricated and tested. Tests included static limit loadings, a modal survey and thermal-vacuum distortion evaluation. The most critical requirement was the demonstration of the dimensional stability provided by the graphite/epoxy truss concept. Crucial to the attainment of this objective was the ability to make very sophisticated thermal growth measurements which was provided by a seven beam laser interferometer. The design of the basic truss elements were tuned to provide the high degree of dimensional stability and stiffness required by the truss. The struts and spider assembly were fabricated with Fiberite's AS/934 and HMS/934 broadgoods. The rings utilized T300 graphite fabricate with the same materials. The predicted performance of the truss was developed using the NASTRAN program. These results showed conformance with the critical stiffness and thermal distortion requirements and correlated well with the test results.

Oken, S.↗
NASA NTRS1975

Transition-radiation-Compton-scattering detector for very relativistic nuclei

The paper presents the design and predicted performance of a large acceptance (2 sq m sr) transition-radiation-Compton-scattering detector system which can be used to measure energy spectra up to several thousand Gev/nucleon for nuclei with Z between 6 and 28, as well as up to 40,000 GeV/nucleon for He. The following circumstances made such a detector system practicable: (1) transition radiation output is proportional to the square of particle charge; (2) output varies at least as rapidly as the square of Lorentz factor over the range from several hundred to several thousand.

Osborne, W. Z.↗
NASA NTRS1976

Digital adaptive control laws for the F-8

NASA is conducting a flight control research program in digital fly-by-wire technology using a modified F-8C aircraft. The first phase of this program used Apollo hardware to demonstrate the practicality of digital fly-by-wire in an actual test vehicle. For the second phase, conventional aircraft sensors and a large floating point digital computer are being utilized to test advanced control laws and redundancy concepts. As part of NASA's research in digital fly-by-wire technology, Honeywell developed digital adaptive flight control laws for flight test in the F-8C. Adaptation of the control laws was to be based on information sensed from conventional aircraft sensors excluding air data. The control laws were constrained to use only existing elevator, rudder, and ailerons as control effectors, each powered by existing actuators. Three adaptive control laws were successfully designed using maximum likelihood estimation, a Liapunov stable model tracker and a self-excited limit cycle concept. The maximum likelihood estimation design was selected as the most promising because of its capability to identify more than surface effectiveness parameters. The adaptive concepts, the control laws and comparisons of predicted performance are described.

Hartmann, G. L.↗
NASA NTRS1976

A report on the aerodynamic design and wind tunnel test of a Prop-Fan model

Recent transport aircraft system studies have shown that the Prop-Fan propulsion system offers the potential for significant fuel savings over high bypass turbofans employing the same core engine technology for each. This important finding has encouraged more detailed study of the Prop-Fan aerodynamics and has led to NASA sponsorship of a wind tunnel research program to explore the projected high efficiency levels of advanced propeller configurations for 0.80 Mach number, high-altitude cruise operation. The aerodynamic design philosophy for the Prop-Fan model is discussed. The geometric characteristics and predicted performance of the wind tunnel model are presented. Finally, the preliminary test results are reviewed and compared to the performance goals originally projected.

Rohrbach, C.↗
NASA NTRS1977

Monitoring Air Pollution from Satellites (MAPS). Volume 1: Technical report

Performance tests on an electro-optical model of an infrared sensor for remote measurements of trace atmospheric gases are detailed; the instrument utilized a sample of the gas to be measured as spectral filter. Also reported is the development of radiometric calibration equipment that determines responses to simulated pollution effects. Results show excellent agreement with theoretical performance predictions with the exception of nonuniform radiance responses. Balance stability to an accuracy better than the rms noise level was demonstrated for the EOM in both the NH3 and CO modes for a period of two days under laboratory conditions. Flight test results show that the temperature range of the absorption cell is restricted to 255 K or higher.

Source record↗
NASA NTRS1977

Pioneer Venus wind experiment receiver

The final design of the Pioneer Venus Wind Experiment Receiver and Phase Calibrator is discussed from the block diagram viewpoint. Measured phase data are shown to derive the predicted performance. The STDN receiver implementation is also discussed.

Nishimura, H.↗
NASA NTRS1976

The Viking Orbiter cameras' potential for photometric measurement

Although photometry of Mars is not listed as a major mission objective, the Viking Project has provided the Orbiter Imaging Team with cameras exhibiting significant improvement in photometric measurement as compared with past Mariners. Sample calibration data are described, together with predicted performance capabilities.

Thorpe, T. E.↗
NASA NTRS1976

CO2 and humidity removal system for extended Shuttle missions - Equilibrium testing and performance analysis

In Shuttle orbiter cabins, lithium hydroxide (LiOH) canisters are currently planned to be used for CO2 adsorption and condensing heat exchangers for humidity control. In this paper a more effective CO2 and humidity removal method is proposed by replacing the LiOH component with HS-C adsorbent (a polyethylenimine coated acrylic ester), thus eliminating the low temperature constraints on the active thermal control system. Since the adsorption of CO2 and H2O are reversible, a double bed configuration operating cyclicly is planned to provide continuous atmospheric control. Apparatus and the experimental procedure to test the adsorption equilibrium are described and some of the indicative results, tabulated by computers, are presented with the help of exponential expressions and differential equations. By using a computer model of the Shuttle HS-C system, performance predictions are made.

Davis, S. H.↗
NASA NTRS1977

Basic coaxial mass driver construction and testing

A basic coaxial mass driver has been constructed by a group of students to verify performance predictions in the acceleration range envisaged for the first lunar device. The bucket is guided by four copper tubes which also supply direct current excitation for its single aluminum coil, and is accelerated by twenty coaxial coils along a 2 m track, followed by a deceleration section. The coils are individually energized by electrolytic photoflash capacitors triggered by solid state switches on the basis of bucket position.

Fine, K.↗
NASA NTRS1976

Dynamic test techniques - Concepts and practices

An initial investigation of dynamic flight test analysis techniques indicated that a strict, comprehensive force-moment accounting system would be necessary. An implementation of the longitudinal force-moment accounting system provided excellent results in accounting for small lift/drag and tail deflection changes. Attention is given to gross thrust calculation, instrumentation, maneuvers, and aspects of data correlation. The results of the studies demonstrate that it is possible to generate a lift/drag model which is capable of predicting performance from nearly any maneuver.

Rawlings, K., III↗
NASA NTRS1975

JANNAF Rocket Engine Performance Test Data Acquisition and Interpretation Manual

Procedures recommended by the JANNAF Performance Standardization Working Group for acquisition and Interpretation of performance test data are presented. Included with the description of these procedures are recommended procedures covering the required measurements, associated instrumentation, calibration methods, and data uncertainties. In addition, criteria for the applicability of existing test data, the selection of test models, and analytical performance prediction improvement based on test results are outlined. Three sample cases using the recommended procedures are presented as an addendum under separate cover. Author

Evans, S. A.↗
NASA NTRS1977

Development of dry coal feeders

Design and fabrication of equipment of feed coal into pressurized environments were investigated. Concepts were selected based on feeder system performance and economic projections. These systems include: two approaches using rotating components, a gas or steam driven ejector, and a modified standpipe feeder concept. Results of development testing of critical components, design procedures, and performance prediction techniques are reviewed.

Bonin, J. H.↗
NASA NTRS1977

Modular control subsystems for use in solar heating systems for multi-family dwellings

Progress in the development of solar heating modular control subsystems is reported. Circuit design, circuit drawings, and printed circuit board layout are discussed along with maintenance manuals, installation instructions, and verification and acceptance tests. Calculations made to determine the predicted performance of the differential thermostat are given including details and results of tests for the offset temperature, and boil and freeze protect points.

Source record↗
NASA NTRS1978

Stirling engine design manual

This manual is intended to serve both as an introduction to Stirling engine analysis methods and as a key to the open literature on Stirling engines. Over 800 references are listed and these are cross referenced by date of publication, author and subject. Engine analysis is treated starting from elementary principles and working through cycles analysis. Analysis methodologies are classified as first, second or third order depending upon degree of complexity and probable application; first order for preliminary engine studies, second order for performance prediction and engine optimization, and third order for detailed hardware evaluation and engine research. A few comparisons between theory and experiment are made. A second order design procedure is documented step by step with calculation sheets and a worked out example to follow. Current high power engines are briefly described and a directory of companies and individuals who are active in Stirling engine development is included. Much remains to be done. Some of the more complicated and potentially very useful design procedures are now only referred to. Future support will enable a more thorough job of comparing all available design procedures against experimental data which should soon be available.

Martini, W. R.↗
NASA NTRS1978

Computer Program for the Design and Off-Design Performance of Turbojet and Turbofan Engine Cycles

The rapid computer program is designed to be run in a stand-alone mode or operated within a larger program. The computation is based on a simplified one-dimensional gas turbine cycle. Each component in the engine is modeled thermo-dynamically. The component efficiencies used in the thermodynamic modeling are scaled for the off-design conditions from input design point values using empirical trends which are included in the computer code. The engine cycle program is capable of producing reasonable engine performance prediction with a minimum of computer execute time. The current computer execute time on the IBM 360/67 for one Mach number, one altitude, and one power setting is about 0.1 seconds. about 0.1 seconds. The principal assumption used in the calculation is that the compressor is operated along a line of maximum adiabatic efficiency on the compressor map. The fluid properties are computed for the combustion mixture, but dissociation is not included. The procedure included in the program is only for the combustion of JP-4, methane, or hydrogen.

Morris, S. J.↗
NASA NTRS1978

The practical impact of elastohydrodynamic lubrication

The use of elastohydrodynamics in the analysis of rolling element bearings is discussed. Relationships for minimum film thickness and tractive force were incorporated into computer codes and used for bearing performance prediction. The lambda parameter (ratio of film thickness to composite surface roughness) was shown to be important in predicting bearing life and failure mode. Results indicate that at values of lambda below 3 failure modes other than the classic subsurface initiated fatigue can occur.

Anderson, W. J.↗