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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 1,747 records · Page 97

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NASA NTRS1974

EMC test plan for shipboard in-harbor and at-sea measurements for L-band terminal

This test plan is to provide a procedure for the measurement of on-board radio frequency interference resulting from the operation of on-board radars (S-Band and X-Band). Field intensity measurements in the range of 1 to 10 GHz will be made using calibrated test instrumentation to determine possible adverse effects to the operation of the future installation of a Maritime L-Band Shipboard Satellite Communications Terminal, for use with the ATS-F and MARISAT Communications Satellites. A measurement will be made of power line conducted interference to determine the degree of power line isolation that may be required. There is also consideration of interference to the radars by the proposed L-Band terminals and observations will be made of the radar displays while L-Band transmitter operation is simulated. These tests will be made aboard the American Alliance container ship, United States Lines.

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NASA NTRS1974

Application of theory to propeller design

The various theories concerning propeller design are discussed. The use of digital computers to obtain specific blade shapes to meet appropriate flow conditions is emphasized. The development of lifting-line and lifting surface configurations is analyzed. Ship propulsive performance and basic propeller design considerations are investigated. The characteristics of supercavitating propellers are compared with those of subcavitating propellers.

Cox, G. G.↗

NASA NTRS1974

Theory of one-element pumps for propulsion

A basic theory for one-element propulsion pumps is developed. A limit to the obtainable efficiency is established and relationships among pump-performance parameters that result in the greatest efficiency are indicated. It is shown that the peripheral velocity of the pump is directly related to ship speed and some relationships between performance parameters and pump geometry are developed. Mathematical models of pump performance are included.

Levy, J.↗

NASA NTRS1973

Applications of radio interferometry to navigation

Radio astronomy experiments have demonstrated the feasibility of making precise position measurements using interferometry techniques. The application of this method to navigation and marine geodesy is discussed, and comparisons are made with existing navigation systems. The very long baseline technique, with a master station, can use either an artificial satellite or natural sources as position references; a high-speed data link is required. A completely ship-borne system is shown to be feasible, at the cost of poorer sensitivity for natural sources. A comparison of Doppler, delay and phase-track modes of operating a very long baseline configuration is made, as that between instantaneous measurements and those where a source can be tracked from horizon to transit. Geometric limitations in latitude and longitude coverage are discussed. The characteristics of natural radio sources, their flux, distribution on the sky, and apparent size are shown to provide a limit on position measurements precision. The atmosphere and frequency standard used both contribute to position measurement uncertainty by affecting interferometric phase.

Knowles, S. H.↗

NASA NTRS1972

Correlation of missions 191, 51M and helicopter photography

The data obtained during aerial photography flights using a helicopter are presented. The areas photographed are identified as three areas within Test Site 175: (1) Rosenberg, (2) Houston Ship Channel/Trinity Bay, and (3) the Somerville Dam. Data are presented in the form of charts. Reproductions of the aerial photographs are included.

Bryan, B. A.↗

NASA NTRS1974

The economic value of remote sensing of earth resources from space: An ERTS overview and the value of continuity of service. Volume 10: Industry

The economic benefits of an ERS system in the area of industrial resources are discussed. Contributions of ERTS imagery to the improvement of shipping routes, detection of previously unknown and potentially active faults in construction areas, and monitoring industrial pollution are described. Due to lack of economic research concerning the subject of ERS applications in this resource area the benefit estimations reported are regarded as tentative and preliminary.

Lietzke, K. R.↗

NASA NTRS1974

Spaceflight tracking and data network operational reliability assessment for Skylab

Data on the spaceflight communications equipment status during the Skylab mission were subjected to an operational reliability assessment. Reliability models were revised to reflect pertinent equipment changes accomplished prior to the beginning of the Skylab missions. Appropriate adjustments were made to fit the data to the models. The availabilities are based on the failure events resulting in the stations inability to support a function of functions and the MTBF's are based on all events including 'can support' and 'cannot support'. Data were received from eleven land-based stations and one ship.

Seneca, V. I.↗

NASA NTRS1974

An interdisciplinary study of the estuarine and coastal oceanography of Block Island Sound and adjacent New York coastal waters

The author has identified the following significant results. Photo-optical additive color quantitative measurements were made of ERTS-1 reprocessed positives of New York Bight and Block Island Sound. Regression of these data on almost simultaneous ship sample data of water's physical, chemical, biological, and optical properties showed that ERTS bands 5 and 6 can be used to predict the absolute value of the total number of particles and bands 4 and 5 to predict the relative extinction coefficient in New York Bight. Water masses and mixing patterns in Block Island Sound heretofore considered transient were found to be persistent phenomena requiring revision of existing mathematical and hydraulic models.

Yost, E. F.↗

NASA NTRS1974

OMEGA navigation system status and future plans

OMEGA is described as a very low frequency (VLF) radio navigational system operating in the internationally allocated navigation band in the electromagentic spectrum between 10 and 14 kilohertz. Full system implementation with worldwide coverage from eight transmitting stations is planned for the latter 1970's. Experimental stations have operated since 1966 in support of system evaluation and test. These stations provided coverage over most of the North Atlantic, North American Continent, and eastern portions of the North Pacific. This coverage provided the fundamental basis for further development of the system and has been essential to the demonstrated feasibility of the one to two nautical mile root-mean-square system accuracy. OMEGA is available to users in all nations, both on ships and in aircraft.

Nolan, T. P.↗

NASA NTRS1975

Skylab mobile laboratory

The Skylab mobile laboratory was designed to provide the capability to obtain necessary data on the Skylab crewmen 30 days before lift-off, within 1 hour after recovery, and until preflight physiological baselines were reattained. The mobile laboratory complex consisted of six laboratories that supported cardiovascular, metabolic, nutrition and endocrinology, operational medicine, blood, and microbiology experiments; a utility package; and two shipping containers. The objectives and equipment requirements of the Skylab mobile laboratory and the data acquisition systems are discussed along with processes such as permanently mounting equipment in the individual laboratories and methods of testing and transporting the units. The operational performance, in terms of amounts of data collected, and the concept of mobile laboratories for medical and scientific experiments are evaluated. The Skylab mobile laboratory succeeded in facilitating the data collection and sample preservation associated with the three Skylab manned flights.

Primeaux, G. R.↗

NASA NTRS1975

L-band, 1.2 m parabolic antenna-noise temperature measurement

Extensive antenna-noise temperature measurements at 1.6 GHz (L-band) were made using a 1.2 m (4 ft. diameter) parabolic dish antenna mounted on the flying bridge of a modern 15,690-ton, commercial-container ship. Both in-harbor and at-sea radiometer measurements were made that indicated a steady background, antenna-noise temperature value slightly less than 70 degrees Kelvin (K) at elevation angles of 5 percent, and greater, at 1.6 GHz. A comparison of theoretical and measured values indicate excellent agreement within about 5K for at-sea data. These measurements are helpful to RF equipment designers of maritime, L-band shipboard terminals for operation with the two, geostationary, maritime satellites, Marisat-A and -B.

Taylor, R. E.↗

NASA NTRS1975

Remote sensing study of Maumee River effects of Lake Erie

The effects of river inputs on boundary waters were studied in partial support of the task to assess the significance of river inputs into receiving waters, dispersion of pollutants, and water quality. The effects of the spring runoff of the Maumee River on Lake Erie were assessed by a combination of ship survey and remote sensing techniques. The imagery obtained from a multispectral scanner of the west basin of Lake Erie is discussed: this clearly showed the distribution of particulates throughout the covered area. This synoptic view, in addition to its qualitative value, is very useful in selecting sampling stations for shipboard in situ measurements, and for extrapolating these quantitative results throughout the area of interest.

Svehla, R.↗

NASA NTRS1975

Great Lakes all-weather ice information system

A system is described which utilizes an X-band Side-Looking-Airborne-Radar (SLAR) for determining type, location, and aerial distribution of the ice cover in the Great Lakes and an airborne, S-band, short pulse radar for obtaining ice thickness. The SLAR system is currently mounted aboard a U.S. Coast Guard C-130B aircraft. Digitized SLAR data are relayed in real-time via the NOAA-GOES-1 satellite in geosynchronous orbit to the U.S. Coast Guard Ice Center in Cleveland, Ohio. SLAR images along with hand-drawn interpretative ice charts for various winter shipping areas in the Great Lakes are broadcast to facsimile recorders aboard Great Lakes vessels. The operational aspects of this ice information system are being demonstrated by NASA, U.S. Coast Guard, and NOAA/National Weather Service. Results from the 1974-75 winter season demonstrated the ability of this system to provide all-weather ice information to shippers in a timely manner.

Schertler, R. J.↗

NASA NTRS1974

Applications Technology Satellite 6 - Upgrading the life style of millions of people

The primary objective of the ATS-6 is to demonstrate the feasibility of operating a high-powered geosynchronous communications satellite capable of relaying color TV and other high-quality signals on multiple frequencies to relatively simple and inexpensive ground receivers. Other capabilities include providing a link between ships, aircraft, or other earth satellites (e.g., low-orbit meteorological satellites) and the ground. The ATS-6 flight-objective accomplishments and subsystem performance for its first 30 days in orbit are summarized. Success is predicted for most of the experiments carried.

Thole, J. M.↗

NASA NTRS1974

Estimation of sea surface temperature from remote sensing in the 11to 13-micron window region

The Nimbus 3 and 4 Iris spectral data in the 11- to 13-micron water vapor window region are analyzed to determine the sea surface temperature (SST). The high spectral resolution data of Iris are averaged over approximately 1-micron-wide intervals to simulate channels of a radiometer to measure the SST. In the present exploratory study, three such channels in the 775- to 960-per cm (12.9-10.5 micron) region are utilized to measure the SST over cloud-free oceans. However, two of these channels are sufficient in routine SST determination. The differential absorption properties of water vapor in the two channels make it possible to determine the water vapor absorption correction without detailed knowledge of the vertical profiles of temperature and water vapor. The feasibility of determining the SST is demonstrated globally with Nimbus 3 data, where cloud-free areas can be selected with the help of albedo data from the medium-resolution infrared radiometer experiment on board the same satellite. The SST derived from this technique agrees with the measurements made by ships to about 1 C.-

Prabhakara, C.↗

NASA NTRS1974

U.S. National Congress of Applied Mechanics, 7th, University of Colorado, Boulder, Colo., June 3-7, 1974, Proceedings

A series of experimental, theoretical, and review papers dealing with various aspects of applied mechanics, including structural analysis, mathematical methods, and fluid dynamics. Some of the topics covered are: the direct formulation of two-dimensional mechanics problems, the mechanical aspects of athletics, Laplace's tidal equations, cochlear mechanics, dynamic constitutive equations, optical techniques for the determination of displacement and strain fields, chemical and biochemical problems involving nonlinear diffusion processes, thermal stresses, the rotating rod viscometer, finite-element methods in plasticity, ships of minimum resistance, and wide-band random vibration of structures. Individual items are announced in this issue.

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NASA NTRS1975

A comprehensive plan for helicopter drag reduction

Current helicopters have parasite drag levels 6 to 10 times as great as fixed wing aircraft. The commensurate poor cruise efficiency results in a substantial degradation of potential mission capability. The paper traces the origins of helicopter drag and shows that the problem (primarily due to bluff body flow separation) can be solved by the adoption of a comprehensive research and development plan. This plan, known as the Fuselage Design Methodology, comprises both nonaerodynamic and aerodynamic aspects. The aerodynamics are discussed in detail and experimental and analytical programs are described which will lead to a solution of the bluff body problem. Some recent results of work conducted at the Naval Ship Research and Development Center (NSRDC) are presented to illustrate these programs. It is concluded that a 75-per cent reduction of helicopter drag is possible by the full implementation of the Fuselage Design Methodology.

Williams, R. M.↗

NASA NTRS1975

An operational all-weather Great Lakes ice information system

A description is given of the NASA developed all-weather ice information system for the Great Lakes winter navigation program. The system utilizes an X-band side looking airborne radar (SLAR) for determining type, location, and areal distribution of the ice cover in the Great Lakes and an airborne, S band, down looking short pulse radar for obtaining ice thickness. Digitized SLAR data are relayed in real time via the NOAA-GOES satellite in geosynchronous orbit. The SLAR images along with hand drawn interpretative ice charts for various Great Lakes winter shipping areas are broadcast to facsimile recorders aboard vessles is the area via the MARAD marine VHF-FM radio network. These data assist such vessels in navigating both through and around the ice.

Gedney, R. T.↗