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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 343 records · Page 19

All sources NASA NTRS DOE OSTI

NASA NTRS2005

Development of X-43A Mach 10 Leading Edges

The nose leading edge of the Hyper-X Mach 10 vehicle was orginally anticipated to reach temperatures near 4000 F at the leading-edge stagnation line. A SiC coated carbon/carbon (C/C) leading-edge material will not survive that extreme temperature for even a short duration single flight. To identify a suitable leading edge for the Mach 10 vehicle, arc-jet testing was performed on thirteen leading-edge segments fabricated from different material systems to evaluate their performance in a simulated flight environment. Hf, Zr, Si, and Ir based materials, in most cases as a coating on C/C, were included in the evaluation. Afterwards, MER, Tucson, AZ was selected as the supplier of the flight vehicle leading edges. The nose and the vertical and horizontal tail leading edges were fabricated out of a 3:1 biased high thermal conductivity C/C. The leading edges were coated with a three layer coating comprised of a SiC conversion of the top surface of the C/C, followed by a chemical vapor deposited layer of SiC, followed by a thin chemical vapor deposited layer of HfC. This paper will describe the fabrication of the Mach 10 C/C leading edges and the testing performed to validate performance.

Ohlhorst, Craig W.↗

NASA NTRS1980

Temperature Sensor

Weed Instrument Inc. produces a line of thermocouples - temperature sensors - for a variety of industrial and research uses. One of the company's newer products is a thermocouple specially designed for high accuracy at extreme temperatures above 3,000 degrees Fahrenheit. Development of sensor brought substantial increases in Weed Instrument sales and employment.

Source record↗

NASA NTRS2018

Mission Design and Implementation Considerations for Lunar Night Survival

Lunar night survival, while being a technical design challenge, also has an impact on mis-sion planning and execution during the flight system development phases (Phases A-D). Depending on mis-sion objectives, different locations on the lunar surface result in different challenges to technical formulation of a comprehensive mission design and implementa-tion. Equatorial regions have temperature extremes between day and night (<100K to >380K) but are somewhat cyclical and predictable. Polar regions can have milder thermal environments in terms of overall surface temperature swing and opportunities for ex-tended durations for solar power but pose unique chal-lenges in temporal and spatial availability of both sun-light and direct-to-Earth communications. Options for surviving the night will depend heavily on mission objectives, lunar location and program cost and schedule constraints.

Vaughan, R.↗

NASA NTRS2002

Evolvable, reconfigurable hardware for future space systems

This paper overviews Evolvable Hardware (EHW) technology, examining its potential for enhancing survivability and flexibility of future space systems. EHW refers to selfconfiguration of electronic hardware by evolutionary/genetic search mechanisms. Evolvable Hardware can maintain existing functionality in the presence of faults and degradations due to aging, temperature and radiation. It can also configure itself for new functionality when required for mission changes or encountered opportunities. The paper illustrates hardware evolution in silicon using a JPL-designed programmable device reconfigurable at transistor level as the platform and a genetic algorithm running on a DSP as the reconfiguration mechanism. Rapid reconfiguration allows convergence to circuit solutions in the order of seconds. The experiments demonstrate functional recovery from faults as well as from degradation at extreme temperatures indicating the possibility of expanding the operational range of extreme electronics through evolved circuit solutions.

Evolvable Hardware EHW↗

DOE OSTI2020

High operating temperature heat transfer fluids for solar thermal power generation. Final report

This is the final technical report for the DOE MURI project on developing high-operating temperature heat transfer fluids for solar thermal power generation. This project aimed to evaluate liquid metals as a heat-transport fluid and potential energy storage medium for concentrated solar powered (CSP) systems. The project consisted of five phases, starting with fluid selection and screen and ending with potential CSP integration. The initial fluid selection arrived at heavy liquid metals as candidate fluids such as lead bismuth eutectic (LBE) as the prime liquid-alloy candidate to be studied, given the conditions above. Fifty-seven liquid compositions were initially identified with liquidus temperatures lower than 200°C, composed of elements that provide no driving force to the reduction of Cr 2 O 3 or Al 2 O 3 passivation layers in pipe material which is required for corrosion prevention. LBE was identified as the primary candidate fluid after these compositions were compared against computational thermodynamic modeling to screen all of the selected systems that would be compatible with our design objectives. Twenty-eight of these compositions were also investigated with the rapid characterization methods; the accuracies of the liquidus temperature and the specific heats predicted by the computations were better than 3 percent and 9 percent, respectively. We conducted numerus corrosion tests of various Fe-Cr-Al based steels in LBE and its variants at temperate as high as 800°C. It was found that minor additions to the liquid did not provide sufficient corrosion protection to warrant their use in real applications. Furthermore, we investigated the detailed mechanism of corrosion between heavy liquid metal and the pipe material at these very high temperatures. A liquid metal loop was constructed to operate at these high temperatures. The loop construction and operation lead to valuable lessons learned that will be needed for industrial scale loops. Furthermore, we learned that electromagnetic pumps at these extreme temperatures will have to be reengineered and redesigned to be used for CSP applications.

14 SOLAR ENERGY↗

DOE OSTI2025

Upper bounds for 21st-century surface air temperatures in the Western United States

The last decade has seen a large number of severe heatwaves that were unprecedented in the observational record, highlighting challenges associated with observationally-based statistical quantification of the likelihood and magnitude of future extreme temperatures. An alternative to such probabilistic assessments is identification of upper bounds that quantify the hottest surface air temperatures that can possibly be achieved by the end of the 21st century. Theory, simulations, and observational analyses support the existence of a finite upper bound for surface air temperature; however, estimates for future upper-bound values that are realistic and usable for planning remain unavailable. Here, we combine atmospheric theory with large ensembles of dynamically downscaled projections to estimate historical and end-of-century upper bounds for surface air temperatures. A number of physical mechanisms can influence upper bounds, and at the end of the 21st century, estimates based on mechanisms that yield more moderate upper-bounds produce values around 60∘C for much of the Western United States and in excess of 80∘C for the hottest parts of the domain. Even cooler high-altitude locations have end-of-century upper bounds over 50∘C. Although these upper-bound estimates might seem implausibly large, increases in the upper bounds over the 21st century are similar to increases in dynamically downscaled peak surface temperatures after adjusting those downscaled temperatures to eliminate the possibly biased model trends in surface specific humidity. While upper bound estimates are high relative to historical observations, they nonetheless suggest that heatwave intensity risk is bounded, with uncertainty dominated by projections of surface and upper-level humidity.

Risser, Mark D↗

DOE OSTI2022

Correcting for digital image correlation speckle inversion at high temperature using color cameras

Digital image correlation (DIC) is a popular, noncontacting technique to measure full-field deformation by using cameras to track the motion of an applied surface pattern. Because it is noncontacting, DIC can be performed for extreme temperature applications (e.g., hot-fire rocket testing of carbon composite rocket nozzles) under harsh conditions during which bonded gauges are damaged. Speckle pattern inversion is a phenomenon that sometimes occurs while performing high-temperature DIC. During speckle pattern inversion, portions of the surface pattern that were initially darker at room temperature (e.g., graphite) may emit more light due to blackbody radiation than the portions that were initially paler, thereby producing images in which the pattern appears inverted at high temperature relative to the initial pattern at room temperature. This phenomenon can prevent the correlation algorithm from being able to resolve the displacements between images. This work compares three methods to mitigate speckle pattern inversion: (A) the subtraction method, a recently-published technique in which two high-temperature images are subtracted to remove unwanted light; (B) the filtering method, a popular technique in which optical bandpass filters screen out unwanted light; and (C) the histogram rescaling method, a proposed new method that pairs a color camera with a blue light source and uses information from the green sensor of the camera to correct against inversion in the blue sensor through postprocessing. The histogram rescaling method is shown to successfully eliminate speckle pattern inversion and has the added advantages that it does not require quasi-static loading to be able to compensate for speckle pattern inversion, nor does it impose thick-glass distortions caused by the optical filter.

Rowley, Lindsey J.↗

NASA NTRS1990

Determination of the durability of the fiberoptics in rocket engine environments

The results of a testing program in which selected optical fibers were exposed to extreme environments representative of those experienced on rocket engines are discussed. Included in the experiment are cold-bend testing, a moisture embrittlement test, a thermal cycling test, temperature extremes testing, vibration testing, and shock testing. Two of the fibers selected, the titanium-carbide-coated and the aluminum-jacketed silica samples succeeded in passing all the tests without a failure.

Delcher, R.↗

NASA NTRS2003

Effects Of Environmental And Operational Stresses On RF MEMS Switch Technologies For Space Applications

Micro Electro Mechanical Systems (MEMS) have been heralded for their ability to provide tremendous advantages in electronic systems through increased electrical performance, reduced power consumption, and higher levels of device integration with a reduction of board real estate. RF MEMS switch technology offers advantages such as low insertion loss (0.1- 0.5 dB), wide bandwidth (1 GHz-100 GHz), and compatibility with many different process technologies (quartz, high resistivity Si, GaAs) which can replace the use of traditional electronic switches, such as GaAs FETS and PIN Diodes, in microwave systems for low signal power (x < 500 mW) applications. Although the electrical characteristics of RF MEMS switches far surpass any existing technologies, the unknown reliability, due to the lack of information concerning failure modes and mechanisms inherent to MEMS devices, create an obstacle to insertion of MEMS technology into high reliability applications. All MEMS devices are sensitive to moisture and contaminants, issues easily resolved by hermetic or near-hermetic packaging. Two well-known failure modes of RF MEMS switches are charging in the dielectric layer of capacitive membrane switches and contact interface stiction of metal-metal switches. Determining the integrity of MEMS devices when subjected to the shock, vibration, temperature extremes, and radiation of the space environment is necessary to facilitate integration into space systems. This paper will explore the effects of different environmental stresses, operational life cycling, temperature, mechanical shock, and vibration on the first commercially available RF MEMS switches to identify relevant failure modes and mechanisms inherent to these device and packaging schemes for space applications. This paper will also describe RF MEMS Switch technology under development at NASA GSFC.

Jah, Muzar↗

DOE OSTI2021

Multiscale Understanding of Surface Structural Effects on High-Temperature Operational Resiliency of Layered Oxide Cathodes

The worldwide energy demand in electric vehicles and the increasing global temperature have called for development of high-energy and long-life lithium-ion batteries (LIBs) with improved high temperature operational resiliency. However, current attention has been mostly focused on cycling aging at elevated temperature, leaving considerable gaps of knowledge in the failure mechanism and practical control of abusive calendar aging and thermal runaway that are highly related to the eventual operational lifetime and safety performance of LIBs. Herein, using a combination of various in situ synchrotron X-ray and electron microscopy techniques, we report a multiscale understanding of surface structure effects involved in regulating the high temperature operational tolerance of polycrystalline Ni-rich layered cathodes. Our results collectively show that an ultraconformal poly (3,4-ethylenedioxythiophene) coating can effectively prevent LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode from undesired phase transformation and transition metal dissolution on the surface, atomic displacement and dislocations within primary particles, intergranular cracking along the grain boundaries within secondary particles, and intensive bulk oxygen release during high state-of-charge and high temperature aging. As a result, the present work highlights the essential role of surface structure controls in overcoming the multiscale degradation pathways of high-energy battery materials at extreme temperature.

25 ENERGY STORAGE↗

NASA NTRS1990

The influence of gas velocity on surface heat pumping for the orifice pulse tube refrigerator

The basic pulse tube refrigerator produces cooling by a mechanism known as surface heat pumping. Cyclical compression and expansion of a gas within an enclosed tube produces large temperature gradients. The purpose of the tube is to act as 'nodal regenerator'. Heat is stored at node positions along the tube wall and is transported between nodes by moving gas parcels. This process gives rise to refrigeration, with hot temperatures at the closed end and cold temperatures at the open end. Unfortunately, much of the available refrigeration is not realized because the closed end of the basic pulse tube restricts gas movement - gas at the extreme temperatures does not come in contact with the heat exchangers. The orifice pulse tube overcomes this limitation by using a valve and surge volume assembly at the warm, closed end. This allows for a residual gas velocity to remain present during the heat transfer process, thereby permitting more gas to exchange heat at the heat exchangers. This paper describes the pulse tube as a nodal regenerator and the effect residual gas velocity has on the heat transfer mechanism of the orifice pulse tube.

Lee, J. M.↗

DOE OSTI2020

Advanced high temperature environmental barrier coating for SiC/SiC ceramic matrix composites

Advanced environmental barrier coating bond coat systems with higher temperature capabilities and environmental resistance are disclosed. These bond coat systems can be applied to ceramic substrates such as SiC/SiC ceramic matrix composite substrates, and can provide protection from extreme temperature, mechanical loading and environmental conditions, such as in high temperature gas turbines. Example bond coat systems can include either an advanced silicon/silicide component, an oxide/silicate component, or a combination thereof.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Advanced high temperature environmental barrier coating systems for SiC/SiC ceramic matrix composites

36 MATERIALS SCIENCE↗

NASA NTRS1984

The effect of direct and reflected radiation on the temperatures of space structures

As an orbiting structure passes from the bright side to the dark side of the earth, substantial differences in surface heating may take place due to direct sunlight and albedo. Most structures are built of convex curved elements to spread out the reflected energy. A change in the shortwave absorptivity and emissivity maintains the temperature of electronic components within a narrow range. Temperature extremes may also be reduced by the use of thermal capacity of the system or by shielding the surface from direct sunlight. For an instrument deployed from a Shuttle, a temperature must be established for it in the cargo bay before deployment. The effect of obstructed views by surfaces such as the Shuttle arm complicates solar flux computations because of the object's mobility. For typical orbits, the earth's albedo and the direct long wavelength radiation may be as much as 30 percent of the direct solar flux. Irradiation due to direct and reflected solar, long wave radiation and reflected radiation from earth, and from Shuttle surfaces is largely dependent on the specular reflection from the radiators as the Shuttle rolls and its surfaces block the sun. Through a judicious choice of surface properties, thermal capacitance and orbit attitude programming, the temperature response of a system can be controlled.

Emery, A. F.↗

NASA NTRS2016

Tropical SNO Comparisons of AIRS and CrIS Calibration for Windows

AIRS (Atmospheric Infrared Sounder) on EOS (Earth Observing System)-Aqua and CrIS (Cross-track Infrared Sounder) on Suomi NPP (National Polar-orbiting Partnership) are two hyperspectral infrared sounders with similar capabilities and orbits, so there is a great opportunity to compare their absolute calibration while they are both in orbit. This insures that long-term climate record can be created by concatenating the two instrument records. There are significant differences in instrument architecture which may lead to subtle differences and complicate attempts to combine the records. We use Tropical Simultaneous Nadir Observations (TSNOs), cases where both instruments are looking nearly at the same place at the same time, to explore the differences. Due to the presence of cold clouds and clear hot desert surface, the data cover a brightness temperature range from 190 degrees Kelvin to 340 degrees Kelvin. We concentrate on the differences between the mean of the two instruments using atmospheric window channels as function of brightness temperature in 20-degree-Kelvin wide bins. With the currently available AIRS and CrIS official calibrated data, radiometric differences as large as 0.3 degrees Kelvin are seen at the extreme temperatures. These differences may be reduced in future releases of the AIRS and CrIS calibration.

CrIS↗

NASA NTRSDate not supplied

Materials for Power Transmission in Extreme Environments

NASA’s goal for a sustained human presence on the Moon and a future Lunar economy requires the development of novel power transmission materials for extreme environments. As an increasing number of public and private entities set their sights towards a future on the Moon, the demand for surface power will dramatically increase – potentially up to megawatt levels. A Lunar economy is envisioned to include a human habitat, manned and unmanned science exploration assets, excavation rovers and systems, and large-scale infrastructure construction such as solar arrays and power grids. A NASA trade study estimated that 1 to 3 km of power transmission lines (1 to 3 KV ac and dc) will be needed over time. Current high power and voltage SOA cables/wire can easily exceed 1 kg/m where mass is not as critical. Connectors, deployment spools and robots further increase the subsystem mass significantly increasing costs. On the other hand, advances in aeronautics provides path towards space missions. The operating environment on the Moon presents substantial risk to safe and reliable power transmission due to space weathering and degradation. These challenges include cosmic and UV radiation, extreme temperatures swings, the electrostatic Lunar exosphere, and the electrostatic and abrasive lunar regolith. The critical need for lightweight, safe and reliable power cables/wires materials is evident. In this presentation, the extreme high altitude and lunar environments and recent materials development from NASA Glenn Research Center’s High Voltage Materials team towards meeting NASA’s objectives and goals for aeronautics and space missions.

Cu/CNT conductors↗

DOE OSTI2023

AlGaN High Electron Mobility Transistor for High-Temperature Logic

Here we report on AlGaN high electron mobility transistor (HEMT)-based logic development, using combined enhancement- and depletion-mode transistors to fabricate inverters with operation from room temperature up to 500°C. Our development approach included: (a) characterizing temperature-dependent carrier transport for different AlGaN HEMT heterostructures, (b) developing a suitable gate metal scheme for use in high temperatures, and (c) over-temperature testing of discrete devices and inverters. Hall mobility data (from 30°C to 500°C) revealed the reference GaN-channel HEMT experienced a 6.9x reduction in mobility, whereas the AlGaN channel HEMTs experienced about a 3.1x reduction. Furthermore, a greater aluminum contrast between the barrier and channel enabled higher carrier densities in the two-dimensional electron gas for all temperatures. The combination of reduced variation in mobility with temperature and high sheet carrier concentration showed that an Al-rich AlGaN-channel HEMT with a high barrier-to-channel aluminum contrast is the best option for an extreme temperature HEMT design. Three gate metal stacks were selected for low resistivity, high melting point, low thermal expansion coefficient, and high expected barrier height. The impact of thermal cycling was examined through electrical characterization of samples measured before and after rapid thermal anneal. The 200-nm tungsten gate metallization was the top performer with minimal reduction in drain current, a slightly positive threshold voltage shift, and about an order of magnitude advantage over the other gates in on-to-off current ratio. After incorporating the tungsten gate metal stack in device fabrication, characterization of transistors and inverters from room temperature up to 500°C was performed. The enhancement-mode (e-mode) devices’ resistance started increasing at about 200°C, resulting in drain current degradation. This phenomenon was not observed in depletion-mode (d-mode) devices but highlights a challenge for inverters in an e-mode driver and d-mode load configuration.

42 ENGINEERING↗

NASA NTRS1986

A model of the spatial and temporal variation of the Uranus thermal structure

Seasonal variability of the temperature structure of Uranus is modeled for all latitudes in the .0004 to 2 bar pressure range in anticipation of the Voyager encounter in January 1986. Atmospheric heating in the model results on the one hand from an internal heat source and, on the other hand, from absorption of solar energy by methane and by non-conservative aerosols located between the 0.5 and 2 bar levels. Various cases for the behavior of the internal heat flux are investigated, such as constant with latitude or constrained to yield a time-averaged thermal emission independent of latitude. Meridional transport of heat in the stably stratified atmosphere is not taken into account. The results indicate that the Voyager encounter time, very small north-south temperature asymmetry should be expected. Moreover, the northern hemisphere, although not illuminated, should emit as much energy (within one percent) as the southern hemisphere at this date. At a given latitude, extreme temperatures are reached at the equinoxes. At the poles, seasonal amplitudes of about 10 K in the upper stratosphere and 6 K at the 0.6 bar level are predicted, and the variation with time of the emission to space is found to be at most 20 percent. The atmosphere of Uranus appears to be characterized by very long radiative response times (mainly due to its cold temperature) which inhibit the large seasonal variations that one could otherwise expect in view of the high obliquity of the planet and its long orbital period.

Bezard, B.↗