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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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

An Overview of Materials Structures for Extreme Environments Efforts for 2015 SBIR Phases I and II

Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for Agency projects. This report highlights innovative SBIR 2015 Phase I and II projects that specifically address areas in Materials and Structures for Extreme Environments, one of six core competencies at NASA Glenn Research Center. Each article describes an innovation, defines its technical objective, and highlights NASA applications as well as commercial and industrial applications. Ten technologies are featured: metamaterials-inspired aerospace structures, metallic joining to advanced ceramic composites, multifunctional polyolefin matrix composite structures, integrated reacting fluid dynamics and predictive materials degradation models for propulsion system conditions, lightweight inflatable structural airlock (LISA), copolymer materials for fused deposition modeling 3-D printing of nonstandard plastics, Type II strained layer superlattice materials development for space-based focal plane array applications, hydrogenous polymer-regolith composites for radiation-shielding materials, a ceramic matrix composite environmental barrier coating durability model, and advanced composite truss printing for large solar array structures. This report serves as an opportunity for NASA engineers, researchers, program managers, and other personnel to learn about innovations in this technology area as well as possibilities for collaboration with innovative small businesses that could benefit NASA programs and projects.

integrated reacting fluid dynamics and predictive ↗
NASA NTRS2017

Creep/Stress Rupture Behavior of 3D Woven SiC/SiC Composites with Sylramic-iBN, Super Sylramic-iBN and Hi-Nicalon-S Fibers at 2700F in Air

To determine the influence of fiber types on creep durability, 3D SiC/SiC CMCs were fabricated with Sylramic-iBN, super Sylramic-iBN and Hi-Nicalon-S fibers and the composite specimens were then tested under isothermal tensile creep at 14820C at 69, 103 and 138 MPa for up to 300hrs in air. The failed specimens were examined by scanning electron microscopy (SEM) and computed tomography (CT) for fracture mode analysis. The creep data of these composites are compared with those of other SiC/SiC composites in the literature. The results of this study will be presented.

failure modes↗
NASA NTRS2018

Degradation of Intercalated Graphite Epoxy Composites Exposed to Low Earth Orbit

Four different graphite fiber/epoxy composites were exposed to the wake-side low Earth orbit (LEO) environment on the Optical Reflector Materials Experiment III (ORMatE-III) platform mounted on the exterior of the ISS for two years in order to determine their long term durability in the space environment. Three of the composite samples used bromine intercalated P100 fibers and one used pristine P100 fibers. One of the P100-Br samples was coated with a protective SiO2 layer, and half of another was coated with SiO2. Results were compared with the EOIM-III experiment which exposed the same materials in LEO in the ram direction for 42 h on the Space Shuttle. Although the atomic oxygen (AO) fluence of the ORMatE-III samples was one-third of the EOIM-III exposure, the resulting effects were qualitatively the same. Both found that SiO2 coated intercalated graphite composites showed no AO erosion, verifying that conventional protection strategies are applicable to bromine intercalated composites. Both found that bromine intercalation does not alter the AO erosion rates of graphite fiber/epoxy composites. Both found no bromine was detected to have migrated into the surrounding epoxy, even for highly eroded fibers and epoxy, allaying fears that bromination could compromise the properties of the epoxy. And both found no corrosive bromine was detected to have been released by the fibers allaying fears that outgassing could degrade sensitive electronics. The uncoated EOIM-III samples suffered slightly greater erosion resulting in a slightly higher solar absorptance. The general conclusion is that ram AO exposure had very similar effects on graphite fiber epoxy composites in both the EOIM-III and ORMatE-III experiments, and in neither case did bromine intercalation of the fibers substantially influence that degradation.

Intercalated graphite↗
NASA NTRS2018

Atomic Oxygen Interactions and the Design of MISSE-9 and MISSE-10 Experiments

Spacecraft in low Earth orbit (LEO) are subjected to harsh environmental conditions, including radiation (cosmic rays, ultraviolet, x-ray, and charged particle radiation), micrometeoroids and orbital debris, temperature extremes, thermal cycling, and atomic oxygen (AO). These environmental exposures can result in erosion, embrittlement and optical property degradation, threatening spacecraft performance and durability. While all of these environmental exposures can cause degradation to spacecraft components, AO is a particularly serious structural, thermal, and optical threat, to exterior oxidizable spacecraft components.

Atomic Oxygen↗
NASA NTRS2019

Atomic Oxygen Erosion Data from the MISSE 2-8 Missions

Polymers and other oxidizable materials on the exterior of spacecraft in the low Earth orbit (LEO) space environment can be eroded from reaction with atomic oxygen (AO). Therefore, in order to design durable spacecraft it is important to know the extent of erosion that will occur during a mission. This can be determined by knowing the LEO AO erosion yield, E(sub y) (volume loss per incident oxygen atom), of materials susceptible to AO reaction. In addition, recent flight experiments have shown that the AO E(sub y) can vary with the AO fluence and/or solar exposure. Therefore obtaining AO E(sub y) data for materials flown on various spaceflight missions is important. NASA Glenn Research Center has flown numerous experiments as part of the Materials International Space Station Experiment (MISSE) missions on the exterior of the International Space Station to characterize the LEO E(sub y) of polymers, composites, protective coatings, and other spacecraft materials. This report provides a summary of the erosion data for ram samples from six Glenn polymer experiments flown as part of MISSE 2, 4, 6, 7, and 8. A total of 71 types of materials with 111 E(sub y) values are provided. The E(sub y) values for uncoated polymers range from 3.81×10(exp –27) cu cm/atom for DC 93-500 silicone exposed to an AO fluence of 4.62×10(exp 21) atoms/sq cm on MISSE 8 to 9.14×10(exp –24) cu cm/atom for polyoxymethylene (POM) exposed to an AO fluence of 8.43×10(exp 21) atoms/sq cm on MISSE 2. One polymer, Triton oxygen resistant, low modulus (TOR(TM) LM), experienced mass gain when exposed to an AO fluence of 2.15×10(exp 21) atoms/sq cm on MISSE 4. In many cases the same material was flown on numerous missions so that trends for E(sub y) versus AO fluence and/or solar exposure can be determined, along with temperature effects.

Erosion↗
NASA NTRSDate not supplied

Protective Coatings for Mitigating Lunar Dust Abrasion and Adhesion

Materials resistant to the harsh lunar environment are needed to support long duration, sustainable missions on the Moon’s surface. Lunar dust poses a significant threat to the durability of components and vehicles due to its fine, jagged morphology and highly abrasive nature. These characteristics result in particles eroding, adhering and/or embedding onto component surfaces and into device confined geometries (e.g., gear housing, interlocking systems, etc.) potentially leading to premature failure. The aim of this work is to identify and characterize wear-resistant materials, including advanced ceramics, for use as protective coatings to minimize abrasion and adhesion caused by lunar dust. Results from testing and evaluation methods devised to elucidate and mimic aspects of lunar dust degradation, including adhesion, abrasion and erosion, as well as the lunar environment, will be presented. Discussion on balancing the need for dust management and tolerance versus dust adhesion mitigation will be shared in context of relevant lunar applications within the NASA Lunar Occupancy Dust Surface Separation Technologies effort, which is part of a NASA-wide effort to enable a sustained lunar presence through the Lunar Surface Innovation Initiative.

lunar dust mitigation↗
NASA NTRS2022

Natural Gas/Oxygen Burner Rig at The NASA Glenn Materials Research Laboratory

This technical memorandum describes the development of a new natural gas/oxygen (NG/O2) fueled burner rig to be used for high-temperature environmental durability studies of advanced materials and components at atmospheric pressure. The burner simulates the high-temperature, high-heat flux, and high-velocity thermal environments encountered in aerospace applications. It will be used to study environmental effects such as water vapor interactions relevant to advanced gas turbine engine materials such as ceramic matrix composites with protective environmental barrier coatings. The highest sample temperature achieved to date in a study of the oxidation and recession of monolithic silicon carbide is 3000 °F.

Burner Rig↗
NASA NTRSDate not supplied

The Development and Use of a Natural Gas / Oxygen Burner Rig for Environmental Barrier Coating and Ceramic Matrix Composite Technology Maturation

This work outlines the development of a new natural gas/oxygen (NG/O2) fueled combustion rig located at the NASA Glenn Research Center for high-temperature environmental durability studies of advanced materials and components at atmospheric pressure. The NG/O2 burner rig can simulate the high-temperature, high-heat flux, and high-velocity thermal environments encountered in gas turbine engines. It also provides the capability to study environmental effects such as water vapor and other foreign contaminants relevant to these applications. The rig is anticipated to bridge the gap between other laboratory methods such as furnaces, jet-fueled burner rigs, high-heat flux lasers, and more expensive engine rig testing. The NG/O2 rig is expected to have maximum sample temperature capabilities over 3,000°F (1,649°C) and result in higher water vapor content compared to our Mach 0.3 to Mach 1.0 jet-A burner rigs which is important for characterizing current and next-generation environmental barrier coatings. This paper will provide an overview of the development of the NG/O2 burner rig, initial characterization, and current research and development efforts on environmental barrier coated ceramic matrix composites.

Burner rig↗
NASA NTRS2023

The Development and Use of a Natural Gas / Oxygen Burner Rig for Environmental Barrier Coating and Ceramic Matrix Composite Technology Maturation

This work outlines the development of a new natural gas/oxygen (NG/O 2 ) fueled combustion rig located at the NASA Glenn Research Center for high-temperature environmental durability studies of advanced materials and components at atmospheric pressure. The NG/O 2 burner rig can simulate the high-temperature, high-heat flux, and high-velocity thermal environments encountered in gas turbine engines. It also provides the capability to study environmental effects such as water vapor and other foreign contaminants relevant to these applications. The rig is anticipated to bridge the gap between other laboratory methods such as furnaces, jet-fueled burner rigs, high-heat flux lasers, and more expensive engine rig testing. The NG/O 2 rig is expected to have maximum sample temperature capabilities over 3,000°F (1,649°C) and result in higher water vapor content compared to our Mach 0.3 to Mach 1.0 jet-A burner rigs which is important for characterizing current and next-generation environmental barrier coatings. This paper will provide an overview of the development of the NG/O 2 burner rig, initial characterization, and current research and development efforts on environmental barrier coated ceramic matrix composites.

Burner rig↗
NASA NTRS1965

Shock absorber protects motive components against overloads

Shock absorber with an output shaft, hollow gear, and a pair of springs forming a resilient driving connection between shaft and gear, operates when abnormally high torques are applied. This simple durable frictional device is valuable in rotating mechanisms subject to sudden overloads.

Source record↗
NASA NTRS1956

Coke Deposition and Smoke Formation in Turbojet Engines

In the early development of jet engines, it was occasionally found that excessive amounts of coke or other carbonaceous deposits were formed in the combustion chamber. Sometimes a considerable amount of smoke was noted in the-exhaust gases. Excessive coke deposits may adversely affect jet-engine performance in several ways. The formation of excessive amounts of coke on or just downstream of a fuel nozzle (figs. 116(a) and (b)) changes the fuel-spray pattern and possibly affects combustor life and performance. Similar effects on performance can result from the deposition of coke on primary-air entry ports (fig. 116(c)). Sea-level or altitude starting may be impaired by the deposition of coke on spark-plug electrodes (fig. 116(b)), deposits either grounding the electrodes completely or causing the spark to occur at positions other than the intended gap. For some time it was thought that large deposits of coke in turbojet combustion chambers (fig. 116(a)) might break away and damage turbine blades; however, experience has indicated that for metal blades this problem is insignificant. (Cermet turbine blades may be damaged by loose coke deposits.) Finally, the deposition of coke may cause high-temperature areas, which promote liner warping and cracking (fig. 116(d)) from excessive temperature gradients and variations in thermal-expansion rates. Smoke in the exhaust gases does not generally impair engine performance but may be undesirable from a tactical or a nuisance standpoint. Appendix B of reference 1 and references 2 to 4 present data obtained from full-scale engines operated on test stands and from flight tests that indicate some effects on performance caused by coke deposits and smoke. Some information about the mechanism of coke formation is given in reference 5 and chapter IX. The data indicate that (1) high-boiling fuel residuals and partly polymerized products may be mixed with a large amount of smoke formed in the gas phase to account for the consistency, structure, and chemical composition of the soft coke in the dome and (2) the hard deposits on the liner are similar to petroleum coke and may result from the liquid-phase thermal cracking of the fuel. During the early development period of jet engines, it was noted that the excessive coke deposits and exhaust smoke were generally obtained when fuel-oil-type fuels were used. Engines using gasoline-type fuels were relatively free from the deposits and smoke. These results indicated that some type of quality control would be needed in fuel specifications. Also noted was the effect of engine operating conditions on coke deposition. It is possible that, even with a clean-burning fuel, an excessive amount of coke could be formed at some operating conditions. In this case, combustor redesign could possibly reduce the coke to a tolerable level. This chapter is a summary of the various coke-deposition and exhaust-smoke problems connected- with the turbojet combustor. Included are (1) the effect of coke deposition on combustor life or durability and performance; (2) the effect of combustor design, operating conditions, inlet variables, and fuel characteristics on coke deposition; (3) elimination of coke deposits; (4) the effect of operating conditions and fuel characteristics on formation of exhaust smoke; and (5) various bench test methods proposed for determining and controlling fuel quality.

Hibbard, R. R.↗
NASA NTRS1968

Compact rotating cup anemometer

Compact, collapsible rotating cup anemometer is used in remote locations where portability and durability are factors in the choice of equipment. This lightweight instrument has a low wind-velocity threshold, is capable of withstanding large mechanical shocks while in its stowed configuration, and has fast response to wind fluctuations.

Wellman, J. B.↗