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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Current research in oxidation-resistant carbon-carbon composites at NASA. Langley Research Center

The significant potential of carbon-carbon composites for high-temperature structural applications is well established. For hypersonic vehicle applications, desirable properties include low density, high specific strength and stiffness, low coefficients of thermal expansion, and retention of mechanical properties above 3000 F. A significant problem associated with carbon materials, however, is that they oxidize rapidly in air at temperatures above about 800 F, and therefore must be protected from oxidation. Successful development of effective methods of oxidation protection is key to the eventual utilization of carbon-carbon composites on hypersonic vehicles such as NASP. In this presentation, the basic elements of an oxidation-protection system are described. Results from oxidation-performance evaluations of state-of-the-art ACC-4 type material in simulated airframe vehicle environments (temperature, pressure, and time) conducted at NASA Langley are also presented. NASA Langley has an active research effort to improve the oxidation resistance of carbon-carbon materials for airframe structural and vehicle thermal protection applications. Conversion coating and sealant development research is highlighted.

Ohlhorst, Craig W.↗
NASA NTRS1988

Curriculum in aerospace science and technology in cooperation with NASA Langley Research Center

A curriculum was written to show teachers how to best use the many resources that are available at the Teacher Resource Center (TRC). This curriculum packet was written using teaching units that teachers in both the elementary and middle schools can use to help students better understand some of the research that has been conducted at NASA and will be conducted in the future. The units are written with certain standards. Each unit contains: (1) specific objectives, using the Virginia standards of learning; (2) the materials that are available from the TRC; (3) many activities that teachers can use in a variety of ways; and (4) specific strategies for measuring the objectives to determine if the students mastered the knowledge, concepts or skills that were taught. The curriculum packet contains specific units on several topics. They are: (1) Careers in Aerospece Science and Technology; (2) The History of Flight; (3) The History of Satellites; (4) The History of the Manned Space Projects and the Future of the Future of the Space Program; (5) The Solar System; and (6) The History of Rockets.

Garner-Gilchrist, Cathine↗
NASA NTRS1991

Damaged stiffened shell research at NASA. Langley Research Center

The structural behavior of stiffened fuselage shells with local cracks is influenced by the local deformations and stress gradients near the cracks, and this behavior must be understood to predict fuselage structural integrity and residual strength. As a crack grows, the stiffness and internal load distributions in a stiffened shell change, affecting the local deformations and stress gradients near the crack. Transport fuselage shells are designed to support internal pressure and mechanical loads which cause a geometrically nonlinear response. Research is being conducted at NASA LaRC to develop and demonstrate a verified nonlinear stiffened shell analysis methodology for accurately predicting the global and local behavior of nonlinear stiffened fuselage shells with local cracks and with combined internal pressure and mechanical loads. The nonlinear structural analysis methodology being developed and planned at NASA LaRC for damaged stiffened fuselage shells and the experiments being planned to verify this analysis methodology are summarized in the present paper.

Aging Aircraft↗
NASA NTRS1992

Composite fuselage shell structures research at NASA Langley Research Center

Fuselage structures for transport aircraft represent a significant percentage of both the weight and the cost of these aircraft primary structures. Composite materials offer the potential for reducing both the weight and the cost of transport fuselage structures, but only limited studies of the response and failure of composite fuselage structures have been conducted for transport aircraft. The behavior of these important primary structures must be understood, and the structural mechanics methodology for analyzing and designing these complex stiffened shell structures must be validated in the laboratory. The effects of local gradients and discontinuities on fuselage shell behavior and the effects of local damage on pressure containment must be thoroughly understood before composite fuselage structures can be used for commercial aircraft. This paper describes the research being conducted and planned at NASA LaRC to help understand the critical behavior or composite fuselage structures and to validate the structural mechanics methodology being developed for stiffened composite fuselage shell structure subjected to combined internal pressure and mechanical loads. Stiffened shell and curved stiffened panel designs are currently being developed and analyzed, and these designs will be fabricated and then tested at Langley to study critical fuselage shell behavior and to validate structural analysis and design methodology. The research includes studies of the effects of combined internal pressure and mechanical loads on nonlinear stiffened panel and shell behavior, the effects of cutouts and other gradient-producing discontinuities on composite shell response, and the effects of local damage on pressure containment and residual strength. Scaling laws are being developed that relate full-scale and subscale behavior of composite fuselage shells. Failure mechanisms are being identified and advanced designs will be developed based on what is learned from early results from the LaRC research activities. Results from combined load tests will be used to validate analytical models of critical nonlinear response mechanisms as well as shell scaling laws.

Starnes, James H., Jr.↗
NASA NTRS2014

Climate Change and Vector Borne Diseases on NASA Langley Research Center

Increasing global temperature, weather patterns with above average storm intensities, and higher sea levels have been identified as phenomena associated with global climate change. As a causal system, climate change could contribute to vector borne diseases in humans. Vectors of concern originate from the vicinity of Langley Research Center include mosquitos and ticks that transmit disease that originate regionally, nationwide, or from outside the US. Recognizing changing conditions, vector borne diseases propagate under climate change conditions, and understanding the conditions in which they may exist or propagate, presents opportunities for monitoring their progress and mitigating their potential impacts through communication, continued monitoring, and adaptation. Personnel comprise a direct and fundamental support to NASA mission success, continuous and improved understanding of climatic conditions, and the resulting consequence of disease from these conditions, helps to reduce risk in terrestrial space technologies, ground operations, and space research. This research addresses conditions which are attributed to climatic conditions which promote environmental conditions conducive to the increase of disease vectors. This investigation includes evaluation of local mosquito population count and rainfall data for statistical correlation and identification of planning recommendations unique to LaRC, other NASA Centers to assess adaptation approaches, Center-level planning strategies.

Cole, Stuart K.↗
NASA NTRS1976

NASA Langley Research Center outreach in astronautical education

The Langley Research Center has traditionally maintained an active relationship with the academic community, especially at the graduate level, to promote the Center's research program and to make graduate education available to its staff. Two new institutes at the Center - the Joint Institute for Acoustics and Flight Sciences, and the Institute for Computer Applications - are discussed. Both provide for research activity at the Center by university faculties. The American Society of Engineering Education Summer Faculty Fellowship Program and the NASA-NRC Postdoctoral Resident Research Associateship Program are also discussed.

Duberg, J. E.↗
NASA NTRS1992

Current state and future direction of computer systems at NASA Langley Research Center

Computer systems have advanced at a rate unmatched by any other area of technology. As performance has dramatically increased there has been an equally dramatic reduction in cost. This constant cost performance improvement has precipitated the pervasiveness of computer systems into virtually all areas of technology. This improvement is due primarily to advances in microelectronics. Most people are now convinced that the new generation of supercomputers will be built using a large number (possibly thousands) of high performance microprocessors. Although the spectacular improvements in computer systems have come about because of these hardware advances, there has also been a steady improvement in software techniques. In an effort to understand how these hardware and software advances will effect research at NASA LaRC, the Computer Systems Technical Committee drafted this white paper to examine the current state and possible future directions of computer systems at the Center. This paper discusses selected important areas of computer systems including real-time systems, embedded systems, high performance computing, distributed computing networks, data acquisition systems, artificial intelligence, and visualization.

Rogers, James L.↗
NASA NTRS1972

Ride quality research activities at NASA Langley Research Center

Ride quality research to determine criteria to describe vehicle performance characteristics which will insure passenger comfort is discussed. The manner in which disciplines of vehicle environmental dynamics, structural dynamics, and electromechanical measurements are combined to define passenger environments is described. The activities of many governmental and private agencies in the field of passenger comfort are examined.

Connor, A. B.↗
NASA NTRS1973

Research on future short-haul aircraft at the NASA Langley Research Center.

Some of the current research for improving our short-haul air-transportation system is reviewed. Promising aircraft range from helicopters, turbofan-powered STOL, through mechanical flap reduced take-off and landing (RTOL) concepts. Advanced rotorcraft technology can provide improved passenger, community, operational, and economic acceptability of civil transport helicopters. From wind-tunnel and design studies, techniques are available for achieving low-noise fixed-wing STOL and RTOL through proper engine and airframe design. Agreeable ride qualities, crosswind landing capability, and all-weather terminal operation are also goals of present effort.

Riebe, J. M.↗
NASA NTRS1973

Engineering analyses and design calculations of NASA, Langley Research Center hydrogen-air-vitiated heater with oxygen replenishment

The technical basis is presented for the design of the hydrogen-air-vitiated heater. The heater liner is subjected to a maximum thermal environment at a specified condition, where the combustion gas temperature, pressure and flow rate are 5000 F, 750 psia, and 11.0 lb/sec, respectively, and results in a heat flux of the order of 275 BTU/sec-sq ft. Cooling and stress analyses indicate that water is the logical choice for cooling of the combustor liner. A mixing analysis was undertaken to establish a good combination of combustor length and injector configuration. The analysis, using a conservative analytical approach, indicates a combustor length of the order of 5 ft combined with discrete fuel and oxidizer injection at an approximate 2-1/2 inch radial combustor position, and results in uniform combustion products at the heater exit for all specified envelope conditions.

Source record↗
NASA NTRS1974

Status of two studies on active control of aeroelastic response at NASA Langley Research Center

The application of active control technology to the suppression of flutter was successfully demonstrated during two recent studies in the Langley transonic dynamics tunnel. The first study involved the implementation of an aerodynamic-energy criterion, using both leading- and trailing-edge controls, to suppress flutter of a simplified delta-wing model. Use of this technique resulted in an increase in the flutter dynamic pressure of approximately 12 percent for this model at a Mach number of 0.9. Analytical methods used to predict the open- and closed-loop behavior of the model are also discussed. The second study, which is a joint effort with the Air Force Flight Dynamics Laboratory, was conducted to establish the effect of active flutter suppression on a model of the Boeing B-52 Configured Vehicle (CCV). Some preliminary results of this study indicate significant improvements in the damping associated with the critical flutter mode.

Abel, I.↗
NASA NTRS1975

Publications in acoustics and noise control from the NASA Langley Research Center during 1940 - 1974

This document contains reference lists of published Langley Research Center papers in various areas of acoustics and noise control for the period 1940-1974. The research work was performed either in-house by the center staff or by other personnel supported entirely or in part by grants or contracts. The references are listed chronologically and are grouped under the following general headings: (1) Duct acoustics, (2) Propagation and operations, (3) Rotating blade noise, (4) Jet noise, (5) Sonic boom, (6) Flow-surface interaction noise, (7) Human response, and (8) Structural response.

Smith, G. C.↗
NASA NTRS1976

Recent progress on new facilities at the NASA Langley Research Center

A new fan-driven high Reynolds number transonic cryogenic tunnel the National Transonic Facility is being planned for the United States. This tunnel will provide an order of magnitude increase in Reynolds number capability over existing tunnels. Theoretical studies and experience with the Langley 1/3 Meter Transonic Cryogenic Tunnel indicate that the cryogenic concept allows the attainment of full-scale Reynolds number at reasonable levels of dynamic pressure. The unique modes of operation which are available only in a cryogenic tunnel make possible the separation of Mach number, Reynolds number possible the separation of Mach number, Reynolds number, and aeroelastic effects. By reducing the drive power requirements to a level where a conventional fan drive system may be used, the cryogenic concept makes possible a tunnel with high productivity and run times sufficiently long to allow for all types of tests at reduced capital costs and, reduced total energy consumption.

Kilgore, R. A.↗
NASA NTRS1977

Publications in acoustics and noise control from the NASA Langley Research Center during 1940-1976

Reference lists are presented of published research papers in various areas of acoustics and noise control for the period 1940-1976. The references are listed chronologically and are grouped under the following general headings: (1) Duct acoustics; (2) propagation and operations; (3) rotating blade noise; (4) jet noise; (5) sonic boom; (6) flow-surface interaction noise; (7) human response; (8) structural response; (9) prediction; and (10) miscellaneous.

Fryer, B. A.↗
NASA NTRS1977

Evaluating of NASA-Langley Research Center explosion seam welding

An explosion bonding technique to meet current fabrication requirements was demonstrated. A test program was conducted on explosion bonded joints, compared to fusion joints in 6061-T6 aluminum. The comparison was made in required fixtures, non-destructive testing, static strength and fatigue strength.

Otto, H. E.↗