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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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

The growth of materials processing in space - A history of government support for new technology

Development of a given technology for national defense and large systems developments when the task is too large or risky for entrepreneurs, yet is clearly in the best interest of the nation are discussed. Advanced research to identify areas of interest was completed. Examples of commercial opportunities are the McDonnell-Douglas Corporation purification process for pharmaceutical products and the Microgravity Research Associates process for growing gallium arsenide crystals in space.

Mckannan, E. C.↗
NASA NTRS1984

Analysis of physical-chemical processes governing SSME internal fluid flows

In order to aid the development of current and future SSME type engines, it is necessary to improve the understanding of basic issues related with physical-chemical processes of SSME internal flows. Accomplishments under each of the following specific objectives are described herein: (1) supplying a state-of-the-art CFD code and graphics package; (2) demonstrating code usage on SSME-related problems to NASA MSFC personnel; and (3) performance computations and analysis of problems relevant to current and future SSME's.

Singhal, A. K.↗
NASA NTRS1984

Analysis of physical-chemical processes governing SSME internal fluid flows

The efforts to adapt CHAM's computational fluid dynamics code, PHOENICS, to the analysis of flow within the high pressure fuel turbopump (HPFTP) aft-platform seal cavity of the SSME are summarized. In particular, the special purpose PHOENICS satellite and ground station specifically formulated for this application are listed and described, and the preliminary results of the first part two-dimensional analyses are presented and discussed. Planned three-dimensional analyses are also briefly outlined. To further understand the mixing and combustion processes in the SSME fuelside preburners, a single oxygen-hydrogen jet element was investigated.

Singhal, A. K.↗
NASA NTRS1984

The management of research institutions: A look at government laboratories

Technology development; project management; employment patterns; research productivity; legal status of support services; functions of senior executives; the role of the sponsoring agency; research diversification; obstacles to technical innovation; organizational structures; and personnel management are addressed.

Mark, H.↗
NASA NTRS1984

Prototype wash water renovation system integration with government-furnished wash fixture

The requirements of a significant quantity of proposed life sciences experiments in Shuttle payloads for available wash water to support cleansing operations has provided the incentive to develop a technique for wash water renovation. A prototype wash water waste renovation system which has the capability to process the waste water and return it to a state adequate for reuse in a typical cleansing fixture designed to support life science experiments was investigated. The resulting technology is to support other developments efforts pertaining to water reclamation by serving as a pretreatment step for subsequent reclamation procedures.

Source record↗
NASA NTRS1985

A Galerkin method for the estimation of parameters in hybrid systems governing the vibration of flexible beams with tip bodies

An approximation scheme is developed for the identification of hybrid systems describing the transverse vibrations of flexible beams with attached tip bodies. In particular, problems involving the estimation of functional parameters are considered. The identification problem is formulated as a least squares fit to data subject to the coupled system of partial and ordinary differential equations describing the transverse displacement of the beam and the motion of the tip bodies respectively. A cubic spline-based Galerkin method applied to the state equations in weak form and the discretization of the admissible parameter space yield a sequence of approximating finite dimensional identification problems. It is shown that each of the approximating problems admits a solution and that from the resulting sequence of optimal solutions a convergent subsequence can be extracted, the limit of which is a solution to the original identification problem. The approximating identification problems can be solved using standard techniques and readily available software.

Banks, H. T.↗
NASA NTRS1985

Analysis of physical-chemical processes governing SSME internal fluid flows

The basic issues concerning the physical chemical processes of the Space Shuttle Main Engine are discussed. The objectives being to supply the general purpose CFD code PHOENICS and the associated interactive graphics package - GRAFFIC; to demonstrate code usage on SSME related problems; to perform computations and analyses of problems relevant to current and future SSME's; and to participate in the development of new physical models of various processes present in SSME components. These objectives are discussed in detail.

Singhal, A. K.↗
NASA NTRS1985

An industry and government survey: A nickel-hydrogen testing data base

A survey of the testing data base for nickel-hydrogen (NiH2) battery cells was performed. The objective of this survey was to evaluate the status of testing of cells in general and of the Air Force design nickel-hydrogen cell in particular. Sufficient detail was sought so that a critical evaluation of the test results and of cell performance could be made. Realizing that subtle differences in test conditions can result in large differences in cell performance, an effort was made to define the actual test environment as closely as possible. These data were obtained in the time period February to May 1984, and reflect the status of tests at that time. Periodic updates of the information are planned. The testing data collected from most North American sources indicates that the basis for use of NiH2 cells in high orbits is firm. Results from over 227 cells produced only 14 failures up to 1000 cycles. The failures are of the type that have either been corrected or would be screened out in a flight program. Recent flight experience appears to support this position.

Badcock, C.↗
NASA NTRS1985

Contractor and government - Teamwork and commitment

Procedures being implemented at NASA to improve cooperation with contractors and increase productivity are reviewed from the NASA point of view. The goals of the U.S. space program for the coming 25 years are listed, and the importance of the commercial utilization of space in these plans is stressed. Consideration is given to the ongoing American Productivity Center White-Collar Productivity-Improvement Project, the implementation of the recommendations of the 1984 NASA/Contractor Conferences in present and future contracts, and the use of incentive contracts to create situations in which both NASA and the contractor benefit from increased productivity. Future plans call for increased industry responsibility in managing and operating the STS; steamlining of Shuttle operations; advanced design-to-cost procedures, increased commonality, better NASA-contractor communications, and more use of CAD/CAM and robotics for the Space Station; and accommodation of greatly expanded private investment and exploitation of space.

Griffin, G. D.↗
NASA NTRS1985

Taylor-Goertler instabilities of Tollmien-Schlichting waves and other flows governed by the interactive boundary layer equations

The Taylor-Gortler vortex instability equations are formulated for steady and unsteady interacting boundary layer flows of the type which arise in triple-deck theory. The effective Gortler number is shown to be a function of the all shape in the boundary layer and the possibility of both steady and unsteady Taylor-Gortler modes exists. As an example the steady flow in a symmetrically constricted channel is considered and it is shown that unstable Gortler vortices exist before the boundary layers at the wall develop the Goldstein singularity. As an example of an unsteady spatially varying basic state the instability of high frequency large amplitude Tollmien-Schlichting waves in a curved channel were considered. It is shown that they are unstable in the first Stokes layer stage of the hierarchy of nonlinear states. The Tollmien-Schlichting waves are shown to be unstable in the presence of both convex and concave curvature.

Hall, P.↗
NASA NTRS1986

Government conceptual estimating for contracting and management

The use of the Aerospace Price Book, a cost index, and conceptual cost estimating for cost-effective design and construction of space facilities is discussed. The price book consists of over 200 commonly used conceptual elements and 100 systems summaries of projects such as launch pads, processing facilities, and air locks. The cost index is composed of three divisions: (1) bid summaries of major Shuttle projects, (2) budget cost data sheets, and (3) cost management summaries; each of these divisions is described. Conceptual estimates of facilities and ground support equipment are required to provide the most probable project cost for budget, funding, and project approval purposes. Similar buildings, systems, and elements already designed are located in the cost index in order to make the best rough order of magnitude conceptual estimates for development of Space Shuttle facilities. An example displaying the applicability of the conceptual cost estimating procedure for the development of the KSC facilities is presented.

Brown, J. A.↗
NASA NTRS1986

Taylor-Goertler instabilities of Tollmien-Schlichting waves and other flows governed by the interactive boundary-layer equations

The Taylor-Goertler vortex instability equations are formulated for steady and unsteady interacting boundary-layer flows. The effective Goertler number is shown to be a function of the wall shape in the boundary layer and the possibility of both steady and unsteady Taylor-Goertler modes exists. As an example the steady flow in a symmetrically constricted channel is considered and it is shown that unstable Goertler vortices exist before the boundary layers at the wall develop the Goldstein singularity discussed by Smith and Daniels (1981). As an example of an unsteady spatially varying basic state, it is considered the instability of high-frequency large-amplitude two- and three-dimensional Tollmien-Schlichting waves in a curved channel. It is shown that they are unstable in the first 'Stokes-layer stage' of the hierarchy of nonlinear states discussed by Smith and Burggraf (1985). This instability of Tollmien-Schlichting waves in an internal flow can occur in the presence of either convex or concave curvature. Some discussion of this instability in external flows is given.

Hall, Philip↗
NASA NTRS1988

On governing equations for crack layer propagation

Results of analysis on damage distribution of a crack layer, in a model material, supported the self-similarity hypothesis of damage evolution which has been adopted by the crack layer theory. On the basis of measurements of discontinuity density and the double layer potential technique, a solution to the crack damage interaction problem has been developed. Evaluation of the stress intensity factor illustrated the methodology. Analysis of experimental results showed that Arrhenius type constitutive relationship described very well the expansion of the active zone of a crack layer.

Chudnovsky, A.↗
NASA NTRS1988

Factors governing water condensation in the Martian atmosphere

Modeling results are presented suggesting a diurnal condensation cycle at high altitudes at some seasons and latitudes. In a previous paper, the use of atmospheric optical depth measurements at the Viking lander site to show diurnal variability of water condensation at different seasons of the Mars year was described. Factors influencing the amount of condensation include latitude, season, atmospheric dust content and water vapor content at the observation site. A one-dimensional radiative-convective model is used herein based on the diabatic heating routines under development for the Mars General Circulation Model. The model predicts atmospheric temperature profiles at any latitude, season, time of day and dust load. From these profiles and an estimate of the water vapor, one can estimate the maximum occurring at an early morning hour (AM) and the minimum in the late afternoon (PM). Measured variations in the atmospheric optical density between AM and PM measurements were interpreted as differences in AM and PM condensation.

Colburn, David S.↗
NASA NTRS1990

Microphysical fundamentals governing cirrus cloud growth: Modeling studies

For application to Global Climate Models, large scale numerical models of cirrus cloud formation and maintenance need to be refined to more reliably simulate the effects and feedbacks of high level clouds. A key aspect is how ice crystal growth is initiated in cirrus, which has started a cloud microphysical controversy between camps either believing that heterogeneous or homogeneous drop freezing is predominantly responsible for cold cirrus ice crystal nucleation. In view of convincing evidence for the existence of highly supercooled cloud droplets in the middle and upper troposphere, however, it is concluded that active ice nuclei are rather scarce at cirrus cloud altitudes, and so a new understanding of cirrus cloud formation is needed. This understanding is sought through an examination of cirrus cloud growth models.

Sassen, Kenneth↗
NASA NTRS1990

Government Information Quarterly. Volume 7, no. 2: National Aeronautics and Space Administration Scientific and Technical Information Programs. Special issue

NASA scientific and technical information (STI) programs are discussed. Topics include management of information in a research and development agency, the new space and Earth science information systems at NASA's archive, scientific and technical information management, and technology transfer of NASA aerospace technology to other industries.

Hernon, Peter↗
NASA NTRS1990

An assessment of the government liquid hydrogen requirements for the 1995-2005 time frame including addendum, liquid hydrogen production and commercial demand in the United States

Liquid hydrogen will continue to be an integral element in virtually every major space program, and it has also become a significant merchant product for certain commercial markets. Liquid hydrogen is not a universally available commodity, and the number of supply sources historically have been limited to regions having concentrated consumption patterns. With the increased space program activity it becomes necessary to assess all future programs on a collective and unified basis. An initial attempt to identify projected requirements on a long range basis is presented.

Bain, Addison↗
NASA NTRS1991

Space education in the context of U.S. Government multiagency efforts in science and mathematics education

The status of a multiagency endeavor to involve U.S. Federal agencies in the attainment of National Education Goals for the 1990's is presented. Emphasis is placed on the educational activities of NASA, which is one of 16 Federal agencies on the Federal Coordinating Council for Science, Engineering and Technology. NASA's is a prototype education program for achieving excellence in mathematics and science in the coming generations of Americans.

Finarelli, Margaret G.↗