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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 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Configuration development study of the X-24C hypersonic research airplane, phase 2

The X-24C Hypersonic Research Vehicle, configured with a heat-sink structure, a launch mass limit of 31.75 Mg and powered by an LR-105 Rocket Engine plus 12 LR-101 Sustainer Engines, was found to be the more cost effective of the candidate configurations. In addition, the configuration provides the maximum off design growth potential capability and subsequently, was selected as the candidate configuration to be subjected to the design refinement study in the remaining segment of the study. Selection of this configuration was based on the analytical study conducted on the performance growth capabilities of the candidate configurations selected from the Phase 1 Study.

Combs, H. G.↗
NASA NTRS1977

Using model order tests to determine sensory inputs in a motion study

In the study of motion effects on tracking performance, a problem of interest is the determination of what sensory inputs a human uses in controlling his tracking task. In the approach presented here a simple canonical model (FID or a proportional, integral, derivative structure) is used to model the human's input-output time series. A study of significant changes in reduction of the output error loss functional is conducted as different permutations of parameters are considered. Since this canonical model includes parameters which are related to inputs to the human (such as the error signal, its derivatives and integration), the study of model order is equivalent to the study of which sensory inputs are being used by the tracker. The parameters are obtained which have the greatest effect on reducing the loss function significantly. In this manner the identification procedure converts the problem of testing for model order into the problem of determining sensory inputs.

Repperger, D. W.↗
NASA NTRS1979

Definition of Mutually Optimum NDI and Proof Test Criteria for 2219 Aluminum Pressure Vessels. Volume 2: Optimization and Fracture Studies

Certain behavioral aspects associated with fracture and crack extension that cannot be studied using other techniques were evaluated with the ultrasonic method. Characterization of collimated beam techniques showed that significant beam width reduction could be accomplished. Techniques for collimation are given. The crack-opening displacement-gage correction-factor study showed that displacement resulting from crack opening and that from plasticity could be readily differentiated. Crack closure studies using both ultrasonic and crack-opening displacement measurements showed an opening and closing behavior associated with load-unload curves. The results of this work were in general agreement with the closure concepts of Elber. Ultrasonic measurements used to study the nature of flaw extension characteristics associated with failure of the ligament between the flaw front and back surface showed that penetration could occur by an abrupt fracturing after subcritical growth or by continuous growth.

Schwartzberg, F. R.↗
NASA NTRS1979

Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type.

Mascitti, V. R.↗
NASA NTRS1977

Space-Based Solar Power Conversion and Delivery Systems Study. Volume 1: Executive Summary

The research concerning space-based solar power conversion and delivery systems is summarized. The potential concepts for a photovoltaic satellite solar power system was studied with emphasis on ground output power levels of 5,000 MW and 10,000 MW. A power relay satellite, and certain aspects of the economics of these systems were also studied. A second study phase examined in greater depth the technical and economic aspects of satellite solar power systems. Throughout this study, the focus was on the economics of satellite solar power. The results indicate technical feasibility of the concept, and provide a preliminary economic justification for the first phase of a substantial development program. A development program containing test satellites is recommended. Also, development of alternative solar cell materials (other than silicon) is recommended.

Source record↗
NASA NTRS1978

Advanced planetary studies

Eleven study tasks are described and key results are discussed for the following: advanced planning activity; cost estimation research; planetary missions performance handbooks-revisions; multiple discipline science assessment; asteroid workshop; galilean lander mission strategies; asteroid exploration study; ion drive transport capabilities; Mars strategy study; Venus surface sample return; and ion drive/solar sail assessment study.

Source record↗
NASA NTRS1979

Energy and cost saving results for advanced technology systems from the Cogeneration Technology Alternatives Study (CTAS)

An overview of the organization and methodology of the Cogeneration Technology Alternatives Study is presented. The objectives of the study were to identify the most attractive advanced energy conversion systems for industrial cogeneration applications in the future and to assess the advantages of advanced technology systems compared to those systems commercially available today. Advanced systems studied include steam turbines, open and closed cycle gas turbines, combined cycles, diesel engines, Stirling engines, phosphoric acid and molten carbonate fuel cells and thermionics. Steam turbines, open cycle gas turbines, combined cycles, and diesel engines were also analyzed in versions typical of today's commercially available technology to provide a base against which to measure the advanced systems. Cogeneration applications in the major energy consuming manufacturing industries were considered. Results of the study in terms of plant level energy savings, annual energy cost savings and economic attractiveness are presented for the various energy conversion systems considered.

Sagerman, G. D.↗
NASA NTRS1977

Auger spectroscopy analysis in adhesion, friction and wear studies

The paper reviews the current use of Auger electron spectroscopy in adhesion, friction, wear and lubrication studies. Conventional Auger spectroscopy is adopted to complement LEED studies of the adhesion of metal single crystals. In addition, Auger cylindrical mirror analysis is applied to the study of changes in surface chemistry during dynamic friction and wear experiments on polycrystalline metals and alloys. Important conclusions are that (1) segregation of alloying elements to the surface of metals can alter adhesion behavior; (2) hydrocarbons are adsorbed readily to clean iron surfaces at 23 C; (3) transfer from one surface to another for dissimilar materials in contact can be followed in sliding or rubbing friction studies; and (4) the friction process can enhance surface activity for metals with hydrocarbons.

Buckley, D. H.↗
NASA NTRS1979

Lewis Research Center studies of multiple large wind turbine generators on a utility network

A NASA-Lewis program to study the anticipated performance of a wind turbine generator farm on an electric utility network is surveyed. The paper describes the approach of the Lewis Wind Energy Project Office to developing analysis capabilities in the area of wind turbine generator-utility network computer simulations. Attention is given to areas such as, the Lewis Purdue hybrid simulation, an independent stability study, DOE multiunit plant study, and the WEST simulator. Also covered are the Lewis mod-2 simulation including analog simulation of a two wind turbine system and comparison with Boeing simulation results, and gust response of a two machine model. Finally future work to be done is noted and it is concluded that the study shows little interaction between the generators and between the generators and the bus.

Gilbert, L. J.↗
NASA NTRS1979

X-ray diffraction studies of shocked lunar analogs

The X-ray diffraction experiments on shocked rock and mineral analogs of particular significance to lunar geology are described. Materials naturally shocked by meteorite impact, nuclear-shocked, or artificially shocked in a flat plate accelerator were utilized. Four areas were outlined for investigation: powder diffractometer studies of shocked single crystal silicate minerals (quartz, orthoclase, oligoclase, pyroxene), powder diffractometer studies of shocked polycrystalline monomineralic samples (dunite), Debye-Scherrer studies of single grains of shocked granodiorite, and powder diffractometer studies of shocked whole rock samples. Quantitative interpretation of peak shock pressures experienced by materials found in lunar or terrestrial impact structures is presented.

Hanss, R. E.↗
NASA NTRS1979

Exploratory studies of the cruise performance of upper surface blown configurations: Experimental program, high-speed pressure tests

Basic pressure data are presented which was obtained from an experimental study of upper-surface blown configurations at cruise. The high-speed (subsonic) experimental work, studying the aerodynamic effects of wing-nacelle geometric variations, was conducted around semi-span model configurations composed of diversified, interchangeable components. Power simulation was provided by high-pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Both 3-D force and 2-D pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first-order power effects. Results are also presented from a compatibility study in which a short-haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High-lift test data are used to substantiate the projected performance of the selected transport design.

Braden, J. A.↗
NASA NTRS1980

Ecological baseline studies

Environmental studies of Merritt Island are discussed. Five areas of the island's ecology are examined. They include: a terrestrial community analyses, a plant community study, a small mammal population study, a rainfall study, and an ichthyological analyses.

Vickers, D.↗
NASA NTRS1980

Exploratory studies of the cruise performance of upper surface blown configurations. Experimental program: Test facilities, model design instrumentation, and lowspeed, high-lift tests

The model hardware, test facilities and instrumentation utilized in an experimental study of upper surface blown configurations at cruise is described. The high speed (subsonic) experimental work, studying the aerodynamic effects of wing nacelle geometric variations, was conducted around semispan model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Three dimensional force and two dimensional pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first order power effects. Results are also presented from a compatibility study in which a short haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High lift test data are used to substantiate the projected performance of the selected transport design.

Braden, J. A.↗
NASA NTRS1980

Exploratory studies of the cruise performance of upper surface blown configurations

The data and major conclusions obtained from an experimental/analytical study of upper-surface blown (USB) configurations at cruise are summarized. The high-speed (subsonic) experimental work, studying the aerodynamic effects of wing-nacelle geometric variations, was conducted around semi-span model configurations composed of diversified, interchangeable components. Power simulation was provided by high pressure air ducted through closed forebody nacelles. Nozzle geometry was varied across size, exit aspect ratio, exit position and boattail angle. Both 3-D force and 2-D pressure measurements were obtained at cruise Mach numbers from 0.5 to 0.8 and at nozzle pressure ratios up to about 3.0. The experimental investigation was supported by an analytical synthesis of the system using a vortex lattice representation with first-order power effects. Results are also presented from a compatibility study in which a short-haul transport is designed on the basis of the aerodynamic findings in the experimental study as well as acoustical data obtained in a concurrent program. High-lift test data are used to substantiate the projected performance of the selected transport design.

Braden, J. A.↗
NASA NTRS1980

Satellite power systems (SPS) concept definition study. Volume 1: Executive summary

System definition studies resulted in a further definition of the reference system using gallium arsenide solar arrays, analysis of alternative subsystem options for the reference concept, preliminary solid state microwave concept studies, and an environmental analysis of laser transmission systems. The special emphasis studies concentrated on satellite construction, satellite construction base definition, satellite construction base construction, and rectenna construction. Major emphasis in the transportation studies was put on definition of a two stage parallel burn, vertical takeoff/horizontal landing concept. The electric orbit transfer vehicle was defined in greater detail. Program definition included cost analyses and schedule definition.

Hanley, G. M.↗
NASA NTRS1980

Low-thrust chemical rocket engine study

Parametric data and preliminary designs on liquid rocket engines for low thrust cargo orbit-transfer-vehicles are described and those items where technology is required to enhance the designs are identified. The results of film cooling studies to establish the upper chamber pressure limit are given. The study showed that regen cooling with RP-1 was not feasible over the entire thrust and chamber pressure ranges. The thermal data showed that the RP-1 bulk temperature exceeded the study coking temperature limit of 1010 R. Based upon the results presented, O2/H2 and O2/CH4 regen engine systems and O2/H2 film cooled engines were selected for further study in the system analysis. Six engine design concepts are examined.

Mellish, J. A.↗
NASA NTRS1980

Gallium arsenide (GaAs) solar cell modeling studies

Various models were constructed which will allow for the variation of system components. Computer studies were then performed using the models constructed in order to study the effects of various system changes. In particular, GaAs and Si flat plate solar power arrays were studied and compared. Series and shunt resistance models were constructed. Models for the chemical kinetics of the annealing process were prepared. For all models constructed, various parametric studies were performed.

Heinbockel, J. H.↗
NASA NTRS1980

Satellite Power Systems /SPS/ - Overview of system studies and critical technology

Systems studies and critical technology issues for the development and evaluation of Satellite Power Systems (SPS) for the photovoltaic generation of electrical energy and its transmission to earth are reviewed. Initial concept studies completed in 1976 and system definition studies initiated in the same year have indicated the technical feasibility of SPS and identified challenging issues to be addressed as part of the SPS Concept Development and Evaluation Program. Systems considered in the study include photovoltaic and solar thermal power conversion configurations employing klystron or solid state microwave generators or lasers for power transmission, and power transmission options, system constructability and in-orbit and ground operations. Technology investigations are being performed in the areas of microwave power transmission, structure/controls interactions and the behavior of key materials in the space/SPS environment. Favorable results have been obtained in the areas of microwave phase distribution and phase control, dc-RF conversion, antenna radiating element, and no insurmountable problems have been discovered in any of the investigations to date.

Manson, S. V.↗