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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 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Cements and a Modeling Tool to Calculate their Viability under Various Exploitation Conditions of HT RTES Systems

Primary cementing is the most important operation performed on a subterranean reservoir. Cement, placed in the annulus between the casing and the formations serves as a hydraulic seal preventing fluids and gas migrations, protecting steel casing from corrosion and supporting the well structure. Poor cementing jobs can be directly responsible for wells not reaching their full capacity, casing corrosion, compromised well integrity and, in the worst-case scenarios, well collapse.

15 GEOTHERMAL ENERGY↗
DOE OSTI2025

3D Printing of Cement-Based Materials Using Seawater for Simulated Marine Environments

Global demand for adaptable and rapidly deployable construction solutions in offshore, coastal, and fluvial environments continues to rise, driven by pressing needs to develop energy platforms, improve coastal resilience, and support emergency response in the face of natural disasters. Increased investment in human-made coastal infrastructure, such as piers, support structures for power lines, offshore wind farms, and seawall protection systems, further underscores this trend. This study investigates the development of printable concrete mixtures for underwater environments using seawater as a replacement for freshwater, using a 3D printing syringe-based extrusion system. The effect of seawater addition and the printing medium (in air vs. underwater) was assessed via rheological and mechanical performance characterization. The results indicate rheological properties are favorable for seawater adoption by producing mixtures with higher yield stress and viscosity with the same levels of admixtures used for freshwater. Seawater-based mixtures demonstrated superior dimensional stability compared to freshwater counterparts, maintaining cross-sectional geometry, while compressive strength results showed no statistical differences between in-air and underwater samples. However, flexural strength was significantly influenced by geometry and printing medium. These findings establish critical rheological parameters for printable underwater mixtures and highlight the need for optimized curing strategies and layer bonding techniques to improve interfacial strength in underwater 3D printing applications.

36 MATERIALS SCIENCE↗
NASA NTRS1974

Metal-wool heat shields for space shuttle

The packaging of metal wool for reusable thermal heat shields applied to aerodynamic and other surfaces for the space shuttle was analyzed and designed, and samples were fabricated and experimentally studied. Parametric trends were prepared for selected configurations. An all-metal thermally efficient, reliable, reusable and producible heat shield system was designed and structurally tested for use on spacecraft aerodynamic surfaces where temperatures do not exceed 810 K. Stainless steel sheet, primarily for structure and secondarily in the transverse plane for thermal expansion, was shown to accommodate thermal expansion in all directions when restrained at the edges and heated to 1360 K. Aerodynamic loads of 0.35 x 1000,000 newtons/sq meter, and higher, may be easily accepted by structures of this design. Seven all-metal thermal protection specimens, 12.7 cm square and 2.5 cm thick were fabricated and are being experimentally evaluated at simulated shuttle entry conditions in an arc jet facility.

Miller, R. C.↗
NASA NTRS1979

Method of making bearing materials

A method is described for making a composite material which provides low friction surfaces for materials in rolling or sliding contact. The composite material which is self-lubricating and oxidation resistant up to and in excess of about 930 C is comprised of a metal component which lends strength and elasticity to the structure and a fluorine salt component which provides oxidation protection to the metal but may also enhance the lubrication qualities of the composite.

Sliney, H. E.↗
NASA NTRS1979

Thermal insulation protection means

A system for providing thermal insulation for portions of a spacecraft which do not exceed 900 F during ascent or reentry relative to the earth's atmosphere is described. The thermal insulation is formed of relatively large flexible sheets of needled Nomex felt having a flexible waterproof coating. The thickness of the felt is sized to protect against projected temperatures and is attached to the structure by a resin adhesive. Vent holes in the sheets allow ventilation while maintaining waterproofing. The system is heat treated to provide thermal stability.

Dotts, R. L.↗
NASA NTRS2008

Electrical Resistance as a NDE Technique to Monitor Processing and Damage Accumulation in SiC/SiC Composites

Ceramic matrix composites are suitable for high temperature structural applications such as turbine airfoils and hypersonic thermal protection systems. The employment of these materials in such applications is limited by the ability to process components reliable and to accurately monitor and predict damage evolution that leads to failure under stressed-oxidation conditions. Current nondestructive methods such as ultrasound, x-ray, and thermal imaging are limited in their ability to quantify small scale, transverse, in-plane, matrix cracks developed over long-time creep and fatigue conditions. Electrical resistance of SiC/SiC composites is one technique that shows special promise towards this end. Since both the matrix and the fibers are conductive, changes in matrix or fiber properties should relate to changes in electrical conductivity along the length of a specimen or part. Initial efforts to quantify the electrical resistance of different fiber and different matrix SiC/SiC composites will be presented. Also, the effect of matrix cracking on electrical resistivity for several composite systems will be presented. The implications towards electrical resistance as a technique applied to composite processing, damage detection, and life-modeling will be discussed.

Smith, Craig↗
NASA NTRS2008

Electrical Resistance Technique to Monitor SiC Composite Detection

Ceramic matrix composites are suitable for high temperature structural applications such as turbine airfoils and hypersonic thermal protection systems. The employment of these materials in such applications is limited by the ability to process components reliable and to accurately monitor and predict damage evolution that leads to failure under stressed-oxidation conditions. Current nondestructive methods such as ultrasound, x-ray, and thermal imaging are limited in their ability to quantify small scale, transverse, in-plane, matrix cracks developed over long-time creep and fatigue conditions. Electrical resistance of SiC/SiC composites is one technique that shows special promise towards this end. Since both the matrix and the fibers are conductive, changes in matrix or fiber properties should relate to changes in electrical conductivity along the length of a specimen or part. The effect of matrix cracking on electrical resistivity for several composite systems will be presented and some initial measurements performed at elevated temperatures under stress-rupture conditions. The implications towards electrical resistance as a technique applied to composite processing, damage detection (health monitoring), and life-modeling will be discussed.

Smith, Craig↗
NASA NTRS2009

Electrical Resistance of SiC/SiC Ceramic Matrix Composites for Damage Detection and Life-Prediction

Ceramic matrix composites (CMC) are suitable for high temperature structural applications such as turbine airfoils and hypersonic thermal protection systems due to their low density high thermal conductivity. The employment of these materials in such applications is limited by the ability to accurately monitor and predict damage evolution. Current nondestructive methods such as ultrasound, x-ray, and thermal imaging are limited in their ability to quantify small scale, transverse, in-plane, matrix cracks developed over long-time creep and fatigue conditions. CMC is a multifunctional material in which the damage is coupled with the material s electrical resistance, providing the possibility of real-time information about the damage state through monitoring of resistance. Here, resistance measurement of SiC/SiC composites under mechanical load at both room temperature monotonic and high temperature creep conditions, coupled with a modal acoustic emission technique, can relate the effects of temperature, strain, matrix cracks, fiber breaks, and oxidation to the change in electrical resistance. A multiscale model can in turn be developed for life prediction of in-service composites, based on electrical resistance methods. Results of tensile mechanical testing of SiC/SiC composites at room and high temperatures will be discussed. Data relating electrical resistivity to composite constituent content, fiber architecture, temperature, matrix crack formation, and oxidation will be explained, along with progress in modeling such properties.

Smith, Craig↗
NASA NTRS2011

Flexible Ablators: Applications and Arcjet Testing

Flexible ablators were conceived in 2009 to meet the technology pull for large, human Mars Exploration Class, 23 m diameter hypersonic inflatable aerodynamic decelerators. As described elsewhere, they have been recently undergoing initial technical readiness (TRL) advancement by NASA. The performance limits of flexible ablators in terms of maximum heat rates, pressure and shear remain to be defined. Further, it is hoped that this emerging technology will vastly expand the capability of future NASA missions involving atmospheric entry systems. This paper considers four topics of relevance to flexible ablators: (1) Their potential applications to near/far term human and robotic missions (2) Brief consideration of the balance between heat shield diameter, flexible ablator performance limits, entry vehicle controllability and aft-body shear layer impingement of interest to designers of very large entry vehicles, (3) The approach for developing bonding processes of flexible ablators for use on rigid entry bodies and (4) Design of large arcjet test articles that will enable the testing of flexible ablators in flight-like, combined environments (heat flux, pressure, shear and structural tensile loading). Based on a review of thermal protection system performance requirements for future entry vehicles, it is concluded that flexible ablators have broad applications to conventional, rigid entry body systems and are enabling to large deployable (both inflatable and mechanical) heat shields. Because of the game-changing nature of flexible ablators, it appears that NASA's Office of the Chief Technologist (OCT) will fund a focused, 3-year TRL advancement of the new materials capable of performance in heat fluxes in the range of 200-600 W/sq. cm. This support will enable the manufacture and use of the large-scale arcjet test designs that will be a key element of this OCT funded activity.

Thermal Protection↗
NASA NTRS2014

Plume Mitigation: Soil Erosion and Lunar Prospecting Sensor Project

Demonstrate feasibility of the simplest, lowest-mass method of measuring density of a cloud of lunar soil ejected by rocket exhaust, using new math techniques with a small baseline laser/camera system. Focus is on exploring the erosion process that occurs when the exhaust plume of a lunar rocket impacts the regolith. Also, predicting the behavior of the lunar soil that would be blasted from a lunar landing/launch site shall assist in better design and protection of any future lunar settlement from scouring of structures and equipment. NASA is gathering experimental data to improve soil erosion models and understand how lunar particles enter the plume flow.

TechPort↗
NASA NTRSDate not supplied

Uranus Probe Entry and Descent Trajectory Design

Uranus has been recently selected as the priority destination for a future Flagship-class mission. The present study designed a mission concept including an orbiter and an atmospheric probe to Uranus. Specific concerns explored by this study included meeting structural requirements under high deceleration loads, designing a Thermal Protection System (TPS) to withstand the high heat fluxes for Uranus entry, and ensuring communication availability for science data up-link between the probe and the orbiter. The results of the study were used to support the 2023-2032 Planetary Science and Astrobiology Decadal Survey.

Uranus Mission Concept↗
NASA NTRS2012

Concept for Hydrogen-Impregnated Nanofiber/Photovoltaic Cargo Stowage System

A stowage system was conceived that consists of collapsible, reconfigurable stowage bags, rigid polyethylene or metal inserts, stainless-steel hooks, flexible photovoltaic materials, and webbing curtains that provide power generation, thermal stabilization, impact resistance, work/sleeping surfaces, and radiation protection to spaceflight hardware and crew members. Providing materials to the Lunar surface is costly from both a mass and a volume standpoint. Most of the materials that will be transferred to other planets or celestial bodies will not be returned to the Earth. In developing a plan to reconfigure pressurized logistics modules, it was determined that there was a requirement to be able to utilize the interior volume of these modules and transform them from Logistics Modules to Storage/Living Quarters. Logistics-to-living must re-utilize stowage bags and the structures that support them to construct living spaces, partitions, furniture, protective shelters from solar particle events, galactic cosmic radiation, and workspaces. In addition to reusing these logistics items for development of the interior living spaces, these items could also be reused outside the habitable volumes to build berms that protect assets from secondary blast ejecta, to define pathways, to stabilize high traffic areas, to protect against dust contamination, to secure assets to mobility elements, to provide thermal protection, and to create other types of protective shelters for surface experiments. Unique features of this innovation include hydrogen-impregnated nano fibers encapsulated in a polyethelyne coating that act as radiation shielding, flexible solar collection cells that can be connected together with cells from other bags via the webbing walls to create a solar array, and the ability to reconfigure each bag to satisfy multiple needs.

Kennedy, Kriss J.↗
DOE OSTI2023

Responsibly Harnessing the Power of AI

Artificial Intelligence (AI) based applications are on the cusp of offering the public and private sectors tools of tremendous potential that will likely transform the world in much the same way that previous technological revolutions have. To harness these tools, a vast and rapidly increasing assortment of ethical AI guidelines and principles are being developed to manage the myriad of risks these tools pose. Documents, frameworks, standards, and regulations have been developed by private industry, research institutions, governments and nongovernmental organizations, international standards bodies and more. This work details representative approaches to ethically developing, managing, and operating current AI technologies. The various approaches are analyzed for commonality, divergence, and implementation strategy to help develop approaches for managing AI tools in the nuclear landscape. This work will support the creation of a common vocabulary and a deeper understanding of the ethical/ responsible AI landscape and advance the considerations required for structured frameworks in the international safeguards domain.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
NASA NTRS1982

Lightning protection of wind turbines

Possible damages to wind turbine components due to lightning strikes are discussed and means to prevent the damage are presented. A low resistance path to the ground is noted to be essential for any turbine system, including metal paths on nonmetal blades to conduct the strike. Surge arrestors are necessary to protect against overvoltages both from utility lines in normal operation and against lightning damage to control equipment and contactors in the generator. MOS structures are susceptible to static discharge injury, as are other semiconductor devices, and must be protected by the presence of static protection circuitry. It is recommended that the electronics be analyzed for the circuit transient response to a lightning waveform, to induced and dc current injection, that input/output leads be shielded, everything be grounded, and lightning-resistant components be chosen early in the design phase.

Dodd, C. W.↗
NASA NTRSDate not supplied

Application of Regolith Polymer Composite FFF Construction in Simulated Lunar Conditions

NASA’s Artemis program has the lofty goal of creating a sustained lunar presence to provide unprecedented opportunities for scientific discovery and to ensure American industry’s access to the unlimited resources and commercial potential in space. To achieve this goal, NASA must incrementally develop and expand its capabilities beyond the short lunar stays of the Apollo program to a robust continued presence with infrastructure and equipment to reduce mission risk by providing safer and more reliable access to the surface, its resources, and protection from the environment. Kennedy Space Center’s Swamp Works Granular Mechanics and Regolith Operations laboratory has partnered with AI SpaceFactory to develop the architectural and structural design of a robotically constructable unpressurized shelter. The shelter, called Lina is designed to protect astronauts and surface assets from radiation, meteoroid impact, moon quakes and thermal gradients. A Fused Filament Fabrication (FFF) construction process using regolith polymer composites was developed. The construction system and associated print parameters are discussed along with the environmental simulation equipment and a summary of test conditions. Test samples were printed in simulated lunar dirty thermal vacuum conditions (~-180 C, ~10-3 torr) and subjected to a series of tests. The resulting strength properties are summarized here, the full details of the material characteristics are provided in a related paper. Lina’s structural design criteria and the resulting initial structure design are detailed in two related papers, this paper presents an update to Lina’s design based on the achieved material strength properties. Finally, a scaled down version of the updated Lina was built on a regolith simulant surface using a novel anchoring technique in simulated lunar vacuum conditions.

lunar infrastructure↗
DOE OSTI2022

Exploring superconductivity at the edge of magnetic or structural instabilities

Modern research of condensed matters devotes in understanding how properties of complex solids are determined by their structural and electronic degrees of freedom. In the last decade, the discovery of Fe-based high-temperature superconductors as well as the discovery of protected surface state in bulk materials arising from the non-trivial topological electronic structures have brought revolutionary breakthroughs, advancing our understanding of the interplay of structure, band topology, spin and charge degrees of freedom to a new level. Despite the exciting progresses, significant materials challenges remain. To address such challenges, our research funded by this award focuses on the design, synthesis and property characterization of two types of quantum materials. One is quasi-two-dimensional materials with structural/magnetic instability, the other is topological materials, especially the “ideal” ones where only minimum non-trivial bands exist at the Fermi level. The objective of our research is to design quantum materials that lie at the edge of structural/magnetic instabilities as well as the ones with non-trivial band topology, aiming at the discovery of quantum materials with emergent phenomena and the in-depth understanding of the entanglement of band topology and various degrees of freedoms through thermodynamic, transport, X-ray, and neutron measurements.

36 MATERIALS SCIENCE↗
NASA NTRS1997

Lightning Effects in the Payload Changeout Room

Analytical and empirical studies have been performed to provide better understanding of the electromagnetic environment inside the Payload Changeout Room and Orbiter payload bay resulting from lightning strikes to the launch pad lightning protection system. The analytical studies consisted of physical and mathematical modeling of the pad structure and the Payload Changeout Room. Empirical testing was performed using a lightning simulator to simulate controlled (8 kA) lightning strikes to the catenary wire lightning protection system. In addition to the analyses and testing listed above, an analysis of the configuration with the vehicle present was conducted, in lieu of testing, by the Finite Difference, Time Domain method.

Thomas, Garland L.↗