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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Feasibility study: Atmospheric general circulation experiment, volume 1

The atmospheric general circulation experiment (AGCE) uses a rotating fluid flow cell assembly. The key technical areas affecting the feasibility of the design and operation of the AGCE are investigated. The areas investigated include materials for the flow cell assembly, thermal design, high voltage power supply design, effective retrieval and handling of experiment data and apparatus configuration. Several materials, DMSO and m-tolunitrile, were selected as candidate fluids for the flow cell principally for their high dielectric constant which permits the high voltage power supply design to be held to 15 kV and still simulate terrestrial gravity. Achievement of a low dissipation factor in the fluid to minimize internal heating from the applied electrical field depends strongly on purification and handling procedures. The use of sapphire as the outer hemisphere for the flow cell provides excellent viewing conditions without a significant impact on attaining the desired thermal gradients. Birefringent effects from sapphire can be held to acceptably low limits. Visualization of flow fluid is achieved through the motion of a dot matrix formed by photochromic dyes. Two dyes found compatible with the candidate fluids are spiropyran and triarylmethane. The observation of the dot motion is accomplished using a flying spot scanner.

Homsey, R. J.↗
NASA NTRS1975

A feasibility study for the detection of upper atmospheric winds using a ground based laser Doppler velocimeter

A possible measurement program designed to obtain the information requisite to determining the feasibility of airborne and/or satellite-borne LDV (Laser Doppler Velocimeter) systems is discussed. Measurements made from the ground are favored over an airborne measurement as far as for the purpose of determining feasibility is concerned. The expected signal strengths for scattering at various altitude and elevation angles are examined; it appears that both molecular absorption and ambient turbulence degrade the signal at low elevation angles and effectively constrain the ground based measurement of elevation angles exceeding a critical value. The nature of the wind shear and turbulence to be expected are treated from a linear hydrodynamic model - a mountain lee wave model. The spatial and temporal correlation distances establish requirements on the range resolution, the maximum detectable range and the allowable integration time.

Thomson, J. A. L.↗
NASA NTRS1994

Reciprocity-based experimental determination of dynamic forces and moments: A feasibility study

BBN Systems and Technologies has been tasked by the Georgia Tech Research Center to carry Task Assignment No. 7 for the NASA Langley Research Center to explore the feasibility of 'In-Situ Experimental Evaluation of the Source Strength of Complex Vibration Sources Utilizing Reciprocity.' The task was carried out under NASA Contract No. NAS1-19061. In flight it is not feasible to connect the vibration sources to their mounting points on the fuselage through force gauges to measure dynamic forces and moments directly. However, it is possible to measure the interior sound field or vibration response caused by these structureborne sound sources at many locations and invoke principle of reciprocity to predict the dynamic forces and moments. The work carried out in the framework of Task 7 was directed to explore the feasibility of reciprocity-based measurements of vibration forces and moments.

Ver, Istvan L.↗
NASA NTRSDate not supplied

Feasibility Study of an All-Electric 150 Passenger Aircraft

Among the potential future technologies for low-carbon transport aircraft, all-electric concepts stand out environmentally, yet their feasibility and cost-effectiveness at scale remain uncertain. This paper examines the conceptual design of an all-electric 150-passenger aircraft with a range of 840 NM based on assumed future battery cell-level specific energy of1620Wh/kg. The tube and wing design is propelled by open rotors driven by four electric motors per nacelle and utilizes advanced structural materials for weight reduction. Powertrain technology gaps are identified. The conceptual design shows that all-electric aviation could supplant about 30% of current fossil fuel use by transport aircraft and potentially more with air-traffic-control modifications.

electric aircraft↗
NASA NTRS1970

X-connectors for tubing - Feasibility study

Connector tests, including 70 deg F leakage and vibration, proof pressure, burst pressure, tensility, thermal shock, high and low temperature leakage, and simultaneous high temperature vibration and leakage, prove feasibility of lightweight 0.5-in. X-connectors for 4500-lb/sq in. service pressures.

Bragg, K.↗
NASA NTRS1973

Feasibility study of full-reactor gas core demonstration test

Separate studies of nuclear criticality, flow patterns, and thermodynamics for the gas core reactor concept have all given positive indications of its feasibility. However, before serious design for a full scale gas core application can be made, feasibility must be shown for operation with full interaction of the nuclear, thermal, and hydraulic effects. A minimum sized, and hence minimum expense, test arrangement is considered for a full gas core configuration. It is shown that the hydrogen coolant scattering effects dominate the nuclear considerations at elevated temperatures. A cavity diameter of somewhat larger than 4 ft (122 cm) will be needed if temperatures high enough to vaporize uranium are to be achieved.

Kunze, J. F.↗
NASA NTRS1986

Feasibility study of a discrete bearing/roller drive rotary joint for the space station

The most critical mechanism on board the proposed space station is the continously rotating joint which must accurately align the solar power units with the sun during earth orbit. The feasibility of a multiple, discrete bearing supported joint driven by a self-loading, pinch drive actuator was investigated for this application. This concept appears to offer greater protection against catastrophic jamming, less sensitivity to adverse thermal gradients, greater accessibility to inorbit servicing or replacement and greater adaptability to very large (5 m) truss members than to more conventional continuous support bearing/gear reducer joints. Analytical trade studies performed herein establish that a discrete cam roller bearing support system having eight hangers around a continuous ring would provide sufficient radial and bending stiffness to prevent any degradation in the fundamental frequencies of the solar wing structure. Furthermore, it appears that the pinch roller drive mechanism can be readily sized to meet or exceed system performance and service life requirements. Wear life estimates based on experimental data for a steel roller coated with an advanced polyimide film show a continuous service life more than two orders of magnitude greater than required for this application.

Loewenthal, S. H.↗
NASA NTRS1980

A feasibility study of a 3-D finite element solution scheme for aeroengine duct acoustics

The advantage from development of a 3-D model of aeroengine duct acoustics is the ability to analyze axial and circumferential liner segmentation simultaneously. The feasibility of a 3-D duct acoustics model was investigated using Galerkin or least squares element formulations combined with Gaussian elimination, successive over-relaxation, or conjugate gradient solution algorithms on conventional scalar computers and on a vector machine. A least squares element formulation combined with a conjugate gradient solver on a CDC Star vector computer initially appeared to have great promise, but severe difficulties were encountered with matrix ill-conditioning. These difficulties in conditioning rendered this technique impractical for realistic problems.

Abrahamson, A. L.↗
NASA NTRS1971

Single-stage earth-orbital reusable vehicle space shuttle feasibility study. Volume 2: Aerodynamic model testing

This volume is one of a 6-volume final report of the Study of a Single-stage Earth-orbital Reusable Vehicle (SERV). The study was conducted by the Chrysler Corporation Space Division (CCSD) for the National Aeronautics and Space Administration, George C. Marshall Space Flight Center under Contract NAS8-26341. The purpose of the study was to evaluate the potential of SERV as the boost element of a candidate space transportation system. To establish the SERV potential, five key technical areas affecting concept feasibility were identified for examination: engine performance, aerodynamic characteristics, thermal protection, subsystem weights, and the landing method. The results of analyses are published in a final reporting consisting of the following six volumes: Volume 1 Summary Volume 2 Aerodynamic Model Testing Volume 3 Concept Evaluation Volume 4 Vehicle Definition Volume 5 Operations Definition Volume 6 Resources

C. E. Tharratt↗
NASA NTRS1991

Adaptive optics in coherent lidar wind measurements: A feasibility study

Laser Doppler radar (lidar) is widely used for remote sensing of wind velocities. Usable wavelengths for the laser are limited by the effects of atmospheric turbulence. An adaptive optical system is proposed to compensate for turbulence effects on signal power. The feasibility of an adaptive system is considered in light of the effects of speckle from the aerosol target. It is concluded that adaptive optics is a promising technique for improving the performance of a 2 micron lidar wind measurement system. The chief technical challenges are a laser that will give the required output and pulse repetition rate, a combined Hartmann sensor and heterodyne detector, and a suitable reconstruction algorithm.

Leland, Robert P.↗
NASA NTRS2014

Feasibility Study of Cargo Airship Transportation Systems Powered by New Green Energy Technologies

The development of transportation systems that use new and sustainable energy technologies is of utmost importance due to the possible future shortfalls that current transportation modes will encounter because of increased volume and costs. The introduction and further research and development of new transportation and energy systems by materials researchers at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) and the Department of Transportation are discussed in this Technical Memorandum. In this preliminary study, airship concepts were assessed for cargo transportation using various green energy technologies capable of 24-hour operation (i.e., night and day). Two prototype airships were successfully constructed and tested at LaRC to demonstrate their feasibility: one with commercially available solar cells for operation during the daytime and one with microwave rectennas (i.e., rectifying antennas) developed in-house for night-time operation. The test results indicate the feasibility of a cargo transportation airship powered by new green energy sources and wireless power technology. Future applications will exploit new green energy sources that use materials and devices recently developed or are in the process of being developed at LaRC. These include quantum well SiGe solar cells; low, mid-, and high temperature thermoelectric modules; and wireless microwave and optical rectenna devices. This study examines the need and development of new energy sources for transportation, including the current status of research, materials, and potential applications.

Skuza, Jonathan R.↗
NASA NTRS1973

Feasibility study of the numerical integration of shell equations using the field method

The field method is developed for arbitrary open branch domains subjected to general linear boundary conditions. Although closed branches are within the scope of the method, they are not treated here. The numerical feasibility of the method has been demonstrated by implementing it in a computer program for the linear static analysis of open branch shells of revolution under asymmetric loads. For such problems the field method eliminates the well-known numerical problem of long subintervals associated with the rapid growth of extraneous solutions. Also, the method appears to execute significantly faster than other numerical integration methods.

Cohen, G. A.↗
NASA NTRS1975

Feasibility study for the implementation of NASTRAN on the ILLIAC 4 parallel processor

The ILLIAC IV, a fourth generation multiprocessor using parallel processing hardware concepts, is operational at Moffett Field, California. Its capability to excel at matrix manipulation, makes the ILLIAC well suited for performing structural analyses using the finite element displacement method. The feasibility of modifying the NASTRAN (NASA structural analysis) computer program to make effective use of the ILLIAC IV was investigated. The characteristics are summarized of the ILLIAC and the ARPANET, a telecommunications network which spans the continent making the ILLIAC accessible to nearly all major industrial centers in the United States. Two distinct approaches are studied: retaining NASTRAN as it now operates on many of the host computers of the ARPANET to process the input and output while using the ILLIAC only for the major computational tasks, and installing NASTRAN to operate entirely in the ILLIAC environment. Though both alternatives offer similar and significant increases in computational speed over modern third generation processors, the full installation of NASTRAN on the ILLIAC is recommended. Specifications are presented for performing that task with manpower estimates and schedules to correspond.

Field, E. I.↗
NASA NTRS1987

Atmospheric Science Field Laboratory - A feasibility study

Plans are underway to transfer the technology represented by the lightning and atmospheric science research facilities and capabilities at the Kennedy Space Center to outside users in other government agencies, private industry, and the academic community. Rocket triggered lightning is being used to demonstrate the feasibility of establishing an Atmospheric Science Field Laboratory as a permanent facility and long-term cost sharing. Results from previous programs and data from a lightning event which occurred during the STS-7 flight are presented to demonstrate the adequacy of the present lightning protection and measuring system to protect personnel, vehicle, and ground equipment, as well as to rapidly assess damage due to a lightning event.

Jafferis, William↗
NASA NTRS2012

Dual-Doppler Feasibility Study

When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any radar geometry issues at the NWS MLB radar, such as the "cone of silence" or beam blockage. In the event of a radar outage at one of the sites, the multi-radar algorithms would provide continuing coverage of the area through use of the data from the remaining operational radar sites. There are several options to collect, edit, synthesize and display dual-Doppler data sets. These options include commercial packages available for purchase and a variety of freeware packages available from the National Center for Atmospheric Research (NCAR) for processing raw radar data. However, evaluation of the freeware packages revealed that they do not have sufficient documentation and configuration control to be certified for 45 SW use. Additionally, a TI data line must be installed/leased from the NWS MLB office and CCAFS to enable the receipt of NWS MLB raw radar data to use in the dual-Doppler synthesis. Integration of the TI data line into the Eastern Range infrastructure that will meet the security requirements necessary for 45 SW use is time-consuming and costly. Overall evaluation indicates that establishment of the dual-Doppler capability using the existing operational radar systems is desirable and feasible with no technical concerns. Installation of such a system represents a significant enhancement to forecasting capabilities at the 45 WS and at NWS MLB. However, data security and cost considerations must be evaluated in light of current budgetary constraints. In any case, gaining the dual-Doppler capability will provide opportunities for better visualization of the wind field and better forecasting of the onset of convection and severe weather events to support space launch operations at KSC and CCAFS.

Huddleston, Lisa L.↗
NASA NTRS1988

X-ray fluorescence surface contaminant analyzer: A feasibility study

The bonding of liner material to the inner metal surfaces of solid rocket booster cases is adversely affected by minute amounts of impurities on the metal surface. Suitable non-destructive methods currently used for detecting these surface contaminants do not provide the means of identifying their elemental composition. The feasibility of using isotopic source excited energy dispersive X-ray fluorescence as a possible technique for elemental analysis of such contaminants is investigated. A survey is made of the elemental compositions of both D-6ac steel, a common construction material for the booster cases, and Conoco HD-2 grease, a common surface contamination. Source and detector choices that maximize signal to noise ratio in a Recessed Source Geometry are made. A Monte Carlo simulation is then made of the optimized device incorporating the latest available X-ray constants at the energy of the chosen source to determine the device's response to a D-6ac steel surface contained with Conoco HD-2 grease.

Eldridge, Hudson B.↗
NASA NTRS1978

Feasibility study for the application of the large format camera as a payload for the Orbiter program

The large format camera (LFC) designed as a 30 cm focal length cartographic camera system that employs forward motion compensation in order to achieve the full image resolution provided by its 80 degree field angle lens is described. The feasibility of application of the current LFC design to deployment in the orbiter program as the Orbiter Camera Payload System was assessed and the changes that are necessary to meet such a requirement are discussed. Current design and any proposed design changes were evaluated relative to possible future deployment of the LFC on a free flyer vehicle or in a WB-57F. Preliminary mission interface requirements for the LFC are given.

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