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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 775 records · Page 43
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Thermal barrier coating life-prediction model development

The program focuses on predicting the lives of two types of strain-tolerant and oxidation-resistant thermal barrier coating (TBC) systems that are produced by commercial coating suppliers to the gas turbine industry. The plasma-sprayed TBC system, composed of a low-pressure plasma-spray (LPPS) or an argon shrouded plasma-spray (ASPS) applied oxidation resistant NiCrAlY or (CoNiCrAlY) bond coating and an air-plasma-sprayed yttria partially stabilized zirconia insulative layer, is applied by both Chromalloy, Klock, and Union Carbide. The second type of TBS is applied by the electron beam-physical vapor deposition (EB-PVD) process by Temescal. The second year of the program was focused on specimen procurement, TMC system characterization, nondestructive evaluation methods, life prediction model development, and TFE731 engine testing of thermal barrier coated blades. Materials testing is approaching completion. Thermomechanical characterization of the TBC systems, with toughness, and spalling strain tests, was completed. Thermochemical testing is approximately two-thirds complete. Preliminary materials life models for the bond coating oxidation and zirconia sintering failure modes were developed. Integration of these life models with airfoil component analysis methods is in progress. Testing of high pressure turbine blades coated with the program TBS systems is in progress in a TFE731 turbofan engine. Eddy current technology feasibility was established with respect to nondestructively measuring zirconia layer thickness of a TBC system.

Strangman, T. E.↗
NASA NTRS1988

Development of a commercial expendable launch vehicle industry

The privatization and commercialization of the expendable launch vehicle (ELV) industry is examined. The government policy to terminate ELV service with the development of the Shuttle is discussed. NASA support to commercial ELVs and privatization and commercialization ELV agreements executed by NASA are considered. The services offered by several companies producing and operating ELVs, and plans for NASA to procure launch services competitively from the private sector are presented.

Stone, Barbara A.↗
NASA NTRS1989

Stellar Inertial Navigation Workstation

Software and hardware assembled to support specific engineering activities. Stellar Inertial Navigation Workstation (SINW) is integrated computer workstation providing systems and engineering support functions for Space Shuttle guidance and navigation-system logistics, repair, and procurement activities. Consists of personal-computer hardware, packaged software, and custom software integrated together into user-friendly, menu-driven system. Designed to operate on IBM PC XT. Applied in business and industry to develop similar workstations.

Johnson, W.↗
NASA NTRS1989

Medical-Information-Management System

Medical Information Management System (MIMS) computer program interactive, general-purpose software system for storage and retrieval of information. Offers immediate assistance where manipulation of large data bases required. User quickly and efficiently extracts, displays, and analyzes data. Used in management of medical data and handling all aspects of data related to care of patients. Other applications include management of data on occupational safety in public and private sectors, handling judicial information, systemizing purchasing and procurement systems, and analyses of cost structures of organizations. Written in Microsoft FORTRAN 77.

Alterescu, Sidney↗
NASA NTRS1988

Chromosomes and plant cell division in space

The objectives were: examination of chromosomal aberrations; development of an experimental system; and engineering design units (EDUs) evaluation. Evaluation criteria are presented. Procedures were developed for shuttle-based investigations which result in the procurement of plant root tips for subsequent cytological examination.

Krikorian, A. D.↗
NASA NTRS1988

Specification for wide channel bandwidth one-inch video tape

Standards and controls are established for the procurement of wide channel bandwidth one inch video magnetic recording tapes for Very Long Base Interferometer (VLBI) system applications. The Magnetic Tape Certification Facility (MTCF) currently maintains three specifications for the Quality Products List (QPL) and acceptance testing of magnetic tapes. NASA-TM-79724 is used for the QPL and acceptance testing of new analog tapes; NASA-TM-80599 is used for QPL and acceptance testing of new digital tapes; and NASA-TM-100702 is used for the QPL and acceptance testing of new IBM/IBM compatible 3480 magnetic tape cartridges. This specification will be used for the QPL and acceptance testing of new wide channel bandwidth one inch video magnetic recording tapes. The one inch video tapes used by the Jet Propulsion Lab., the Deep Space Network and the Haystack Observatory will be covered by this specification. These NASA stations will use the video tapes for their VLBI system applications. The VLBI system is used for the tracking of quasars and the support of interplanetary exploration.

Perry, Jimmy L.↗
NASA NTRS1988

LIGO vacuum system study

A laser interferometer gravitational wave observatory (LIGO) is being developed with sensitivities which will have a high probability of detecting gravitational waves from astrophysical sources. A major component of LIGO is a total of 16 km of 1.2 m (48 inch) diameter tube at a pressure of less than 10 to the minus 8th power torr. It will be of 304L stainless steel procured directly from the steel mills with the initial hydrogen content specially reduced. Projections of the outgassing rates of hydrogen and of water vapor as a function of time are given and the uncertainties discussed. Based on these, a preliminary analysis of the vacuum system is presented.

Livas, Jeffrey C.↗
NASA NTRS1988

A study of microstructural characteristics of Ni-based superalloys at high temperatures

The microstructural characteristics of the Ni-based superalloy MAR-M246(Hf) which is used in manufacturing the components of the Space Shuttle's main engine have been studied. These superalloys need optimal heat treatment to get the best results. To find the optimum heat treatment the technique of differential thermal analysis and the optical photomicrographs are being planned to be utilized. In the first phase, the existing experimental equipment like cutting, grinding/polishing machines and metallurgical microscope have been set up to cut/polish and take the photomicrographs. In the beginning of this year an order was placed for the Leitz Mettalux-3 microscope with a hot stage for in-situ observation of the superalloy samples. The hot stage was tested for the first time, alloying the thermocouple with the Tantulum heating element and has not been installed finally by the supplier. A Perkin Elmer Differential Thermal Analyzer (DTA 1700) was procured in the first year of the project. Samples of MAR-M246(Hf), MAR-M247, Waspaloy, Udimet-41, CMSX-2 and CMSX-3 (polycrystalline and single crystals) have been studied using differential thermal analyzer.

Lal, R. B.↗
NASA NTRS1985

Characterization of ZrO2-Y2O3 thermal spray powder systems

The overall objective is to establish the interrelation between the raw material in the coating process and the performance of the coating deposit. It is anticipated that these interrelations will help establish more precise specifications for the procurement of the raw materials. Some of the preliminary results of the program are presented.

Mantkowski, Thomas E.↗
NASA NTRS1988

Knowledge-based operation and management of communications systems

Expert systems techniques are being applied in operation and control of the Defense Communications System (DCS), which has the mission of providing reliable worldwide voice, data and message services for U.S. forces and commands. Thousands of personnel operate DCS facilities, and many of their functions match the classical expert system scenario: complex, skill-intensive environments with a full spectrum of problems in training and retention, cost containment, modernization, and so on. Two of these functions are: (1) fault isolation and restoral of dedicated circuits at Tech Control Centers, and (2) network management for the Defense Switched Network (the modernized dial-up voice system currently replacing AUTOVON). An expert system for the first of these is deployed for evaluation purposes at Andrews Air Force Base, and plans are being made for procurement of operational systems. In the second area, knowledge obtained with a sophisticated simulator is being embedded in an expert system. The background, design and status of both projects are described.

Heggestad, Harold M.↗
NASA NTRS1989

A (13)C NMR analysis of the effects of electron radiation on graphite/polyetherimide composites

Initial investigations have been made into the use of high resolution nuclear magnetic resonance (NMR) for the characterization of radiation effects in graphite and Kevlar fibers, polymers, and the fiber/matrix interface in graphite/polyetherimide composites. Sample preparation techniques were refined. Essential equipment has been procured. A new NMR probe was constructed to increase the proton signal-to-noise ratio. Problem areas have been identified and plans developed to resolve them.

Ferguson, Milton W.↗
NASA NTRS1989

Calculation of turbulence-driven secondary motion in ducts with arbitrary cross section

Calculation methods for turbulent duct flows are generalized for ducts with arbitrary cross-sections. The irregular physical geometry is transformed into a regular one in computational space, and the flow equations are solved with a finite-volume numerical procedure. The turbulent stresses are calculated with an algebraic stress model derived by simplifying model transport equations for the individual Reynolds stresses. Two variants of such a model are considered. These procedures enable the prediction of both the turbulence-driven secondary flow and the anisotropy of the Reynolds stresses, in contrast to some of the earlier calculation methods. Model predictions are compared to experimental data for developed flow in triangular duct, trapezoidal duct and a rod-bundle geometry. The correct trends are predicted, and the quantitative agreement is mostly fair. The simpler variant of the algebraic stress model procured better agreement with the measured data.

Demuren, A. O.↗
NASA NTRS1988

Commercial ELV services and the National Aeronautics and Space Administration - Concord or discord?

In implementation of the U.S. policy to foster and encourage the commercial expendable launch vehicle (ELV) industry, tensions have developed between the industry and U.S. Government agencies in two distinct areas: industry use of government facilities and government purchase of commercial ELV services. The reasons for the tensions and discrete legal problems for each area are identified and discussed. Specifically, in the use of government facilities area, issues of insurance and indemnification for third-party liability and government property, concerns over priority and scheduling, and dispute-resolution procedures are discussed. In the area of government purchase of ELV launch services, a comparison is made between a launch service purchase and prior procurement practice. In all areas, the conclusion is reached that while problems still exist, they generally are understood and great progress has been made toward their resolution.

Frankle, Edward A.↗
NASA NTRS1989

Application of multi-grid methods for solving the Navier-Stokes equations

This paper presents the application of a class of multi-grid methods to the solution of the Navier-Stokes equations for two-dimensional laminar flow problems. The methods consists of combining the full approximation scheme-full multi-grid technique (FAS-FMG) with point-, line- or plane-relaxation routines for solving the Navier-Stokes equations in primitive variables. The performance of the multi-grid methods is compared to those of several single-grid methods. The results show that much faster convergence can be procured through the use of the multi-grid approach than through the various suggestions for improving single-grid methods. The importance of the choice of relaxation scheme for the multi-grid method is illustrated.

Demuren, A. O.↗
NASA NTRS1988

Ada (trademark) projects at NASA. Runtime environment issues and recommendations

Ada practitioners should use this document to discuss and establish common short term requirements for Ada runtime environments. The major current Ada runtime environment issues are identified through the analysis of some of the Ada efforts at NASA and other research centers. The runtime environment characteristics of major compilers are compared while alternate runtime implementations are reviewed. Modifications and extensions to the Ada Language Reference Manual to address some of these runtime issues are proposed. Three classes of projects focusing on the most critical runtime features of Ada are recommended, including a range of immediately feasible full scale Ada development projects. Also, a list of runtime features and procurement issues is proposed for consideration by the vendors, contractors and the government.

Roy, Daniel M.↗
NASA NTRS1989

Final Environmental Impact Statement for the Galileo Mission (Tier 2)

This Final Environmental Impact Statement (FEIS) addresses the proposed action of completing the preparation and operation of the Galileo spacecraft, including its planned launch on the Space Transportation System (STS) Shuttle in October 1989, and the alternative of canceling further work on the mission. The Tier 1 (program level) EIS (NASA 1988a) considered the Titan IV launch vehicle as an alternative booster stage for launch in May 1991 or later. The May 1991 Venus launch opportunity is considered a planetary back-up for the Magellan (Venus Radar Mapper) mission, the Galileo mission, and the Ulysses mission. Plans were underway to enable the use of a Titan IV launch vehicle for the planetary back-up. However, in November 1988, the U.S. Air Force, which procures the Titan IV for NASA, notified NASA that it could not provide a Titan IV vehicle for the May 1991 launch opportunity due to high priority Department of Defense requirements. Consequently, NASA terminated all mission planning for the Titan IV planetary back-up. A minimum of 3 years is required to implement mission-specific modifications to the basic Titan IV launch configuration; therefore, insufficient time is available to use a Titan IV vehicle in May 1991. Thus, the Titan IV launch vehicle is no longer a feasible alternative to the STS/Inertial Upper Stage (IUS) for the May 1991 launch opportunity.

Source record↗
NASA NTRS1989

A high-speed digital camera system for the observation of rapid H-alpha fluctuations in solar flares

Researchers developed a prototype digital camera system for obtaining H-alpha images of solar flares with 0.1 s time resolution. They intend to operate this system in conjunction with SMM's Hard X Ray Burst Spectrometer, with x ray instruments which will be available on the Gamma Ray Observatory and eventually with the Gamma Ray Imaging Device (GRID), and with the High Resolution Gamma-Ray and Hard X Ray Spectrometer (HIREGS) which are being developed for the Max '91 program. The digital camera has recently proven to be successful as a one camera system operating in the blue wing of H-alpha during the first Max '91 campaign. Construction and procurement of a second and possibly a third camera for simultaneous observations at other wavelengths are underway as are analyses of the campaign data.

Kiplinger, Alan L.↗
NASA NTRS1989

Application of multi-grid methods for solving the Navier-Stokes equations

The application of a class of multi-grid methods to the solution of the Navier-Stokes equations for two-dimensional laminar flow problems is discussed. The methods consist of combining the full approximation scheme-full multi-grid technique (FAS-FMG) with point-, line-, or plane-relaxation routines for solving the Navier-Stokes equations in primitive variables. The performance of the multi-grid methods is compared to that of several single-grid methods. The results show that much faster convergence can be procured through the use of the multi-grid approach than through the various suggestions for improving single-grid methods. The importance of the choice of relaxation scheme for the multi-grid method is illustrated.

Demuren, A. O.↗