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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

NASA Tech Briefs, March 2011

Topics covered include: Optimal Tuner Selection for Kalman-Filter-Based Aircraft Engine Performance Estimation; Airborne Radar Interferometric Repeat-Pass Processing; Plug-and-Play Environmental Monitoring Spacecraft Subsystem; Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz; Wallops Ship Surveillance System; Source Lines Counter (SLiC) Version 4.0; Guidance, Navigation, and Control Program; Single-Frame Terrain Mapping Software for Robotic Vehicles; Auto Draw from Excel Input Files; Observation Scheduling System; CFDP for Interplanetary Overlay Network; X-Windows Widget for Image Display; Binary-Signal Recovery; Volumetric 3D Display System with Static Screen; MMIC Replacement for Gunn Diode Oscillators; Feature Acquisition with Imbalanced Training Data; Mount Protects Thin-Walled Glass or Ceramic Tubes from Large Thermal and Vibration Loads; Carbon Nanotube-Based Structural Health Monitoring Sensors; Wireless Inductive Power Device Suppresses Blade Vibrations; Safe, Advanced, Adaptable Isolation System Eliminates the Need for Critical Lifts; Anti-Rotation Device Releasable by Insertion of a Tool; A Magnetically Coupled Cryogenic Pump; Single Piezo-Actuator Rotary-Hammering Drill; Fire-Retardant Polymeric Additives; Catalytic Generation of Lift Gases for Balloons; Ionic Liquids to Replace Hydrazine; Variable Emittance Electrochromics Using Ionic Electrolytes and Low Solar Absorptance Coatings; Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger; Multi-Mission Power Analysis Tool; Correction for Self-Heating When Using Thermometers as Heaters in Precision Control Applications; Gravitational Wave Detection with Single-Laser Atom Interferometers; Titanium Alloy Strong Back for IXO Mirror Segments; Improved Ambient Pressure Pyroelectric Ion Source; Multi-Modal Image Registration and Matching for Localization of a Balloon on Titan; Entanglement in Quantum-Classical Hybrid; Algorithm for Autonomous Landing; Quantum-Classical Hybrid for Information Processing; Small-Scale Dissipation in Binary-Species Transitional Mixing Layers; Superpixel-Augmented Endmember Detection for Hyperspectral Images; Coding for Parallel Links to Maximize the Expected Value of Decodable Messages; and Microwave Tissue Soldering for Immediate Wound Closure.

Source record↗
DOE OSTI2026

Enhanced Simulation Tools for Scheduling Solar Plus Storage Power Plants

This is the final technical report for the Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Solar Energy Technology's Office Balance of Systems program, Award Number 38429. This report summarizes the key outputs and findings of the project, which was focused on long-duration energy storage (LDES) and solar. In particular, one of the most significant challenges of maximizing the value of variable solar energy is the timing of charging and discharging stored energy from LDES devices. Power systems often fail to capture the benefits of LDES and can undervalue the role of storage in providing energy arbitrage, reliability support, and resiliency. This project examined those challenges and proposed alternative methodologies that better capture the value that LDES can provide.

14 SOLAR ENERGY↗
DOE OSTI2021

Ultrawide-bandgap semiconductors: An overview

Ultrawide-bandgap (UWBG) semiconductor technology is presently going through a renaissance exemplified by advances in material-level understanding, extensions of known concepts to new materials, novel device concepts, and new applications. as such, this focus issue presents a timely selection of papers spanning the current state of the art in UWBG materials and applications, including both experimental results and theoretical developments. It covers broad research subtopics on UWBG bulk crystals and substrate technologies, UWBG defect science and doping, UWBG epitaxy, UWBG electronic and optoelectronic properties, and UWBG power devices and emitters. In this overview article, we consolidate the fundamentals and background of key UWBG semiconductors including aluminum gallium nitride alloys (Al x Ga 1– x N), boron nitride (BN), diamond, β-phase gallium oxide (β-Ga 2 O 3 ), and a number of other UWBG binary and ternary oxides.

36 MATERIALS SCIENCE↗
NASA NTRS1994

Design of an unmanned Martian polar exploration system

The design of an unmanned Martian polar exploration system is presented. The system elements include subsystems for transportation of material from earth to Mars, study of the Martian north pole, power generation, and communications. Early next century, three Atlas 2AS launch vehicles will be used to insert three Earth-Mars transfer vehicles, or buses, into a low-energy transfer orbit. Capture at Mars will be accomplished by aerobraking into a circular orbit. Each bus contains four landers and a communications satellite. Six of the twelve total landers will be deployed at 60 deg intervals along 80 deg N, and the remaining six landers at 5 deg intervals along 30 deg E from 65 deg N to 90 deg N by a combination of retrorockets and parachutes. The three communications satellites will be deployed at altitudes of 500 km in circular polar orbits that are 120 deg out of phase. These placements maximize the polar coverage of the science and communications subsystems. Each lander contains scientific equipment, two microrovers, power supplies, communications equipment, and a science computer. The lander scientific equipment includes a microweather station, seismometer, thermal probe, x-ray spectrometer, camera, and sounding rockets. One rover, designed for short-range (less than 2 km) excursions from the lander, includes a mass spectrometer for mineral analysis, an auger/borescope system for depth profiling, a deployable thermal probe, and charge coupled device cameras for terrain visualization/navigation. The second rover, designed for longer-range (2-5 km) excursions from the lander, includes radar sounding/mapping equipment, a seismometer, and laser ranging devices. Power for all subsystems is supplied by a combination of solar cells, Ni-H batteries, and radioisotope thermoelectric generators. Communications are sequenced from rovers, sounding rockets, and remote sensors to the lander, then to the satellites, through the Deep Space Network to and from earth.

Baldwin, Curt↗
DOE OSTI2022

Internal Reaction Mass Taxonomy and Narrow-Down Study

Internal reaction mass (IRM) wave energy converters (WEC) capture wave energy by reacting against a moving mass that is suspended within their hulls. Due to their hermetically sealed Power Take Off (PTO), compact form factor and relatively simple mooring requirements, the National Renewable Energy Laboratory has identified IRM WECs are good candidates for applications such as ocean observation. A literature review of existing IRM mechanisms lead to the classification of IRM WECs based on their principal method of energy capture and principal axes of operation. The IRM categories include sliding mass, pendular and gyroscopic devices. A narrow down study was conducted to ascertain the most promising mechanisms for further investigation; devices were evaluated based on a decision matrix of weighted criteria that included device power output, prototypability and power to mass ratio. The narrow down study identified the issue of achieving resonance with pendulum-based designs, as well as the poor response produced by reaction to long period waves. Chaotic pendula and methods to multiply agitation were identified as a means to increase power output. Alternative methods of power generation, such as triboelectric nanogenerators, were also identified as a technology that would benefit from multiplied agitation and chaotic motion. This work was funded under the U.S. Department of Energy's Water Power Technologies Office's Powering the Blue Economy portfolio.

ENGINEERING,TIDAL AND WAVE POWER↗
NASA NTRS2018

Piezoelectric Charging and Wireless Communication

Modern medicine is undergoing a revolution in the application of new sensor capabilities for aiding in diagnosis of specific conditions and monitoring a variety of informative vital signs. In the past, many of the measurements were limited by what could be accomplished externally. A shift toward in-vivo monitoring for both diagnostic and therapeutic sensing and actuation [1] has created a need for low power electronics, high energy density batteries and methods to successfully power devices embedded in the body. For a review of the field and sensing capabilities see [2]. Recent studies suggest that charging with ultrasound is more efficient at longer transmission distance (> 10cm) than inductive charging [3]. In this manuscript, we discuss the modeling and experimentation that we have accomplished and demonstrate in ultrasonic charging of sensors having the form and fit of in-vivo sensors. The task goal has been to use piezoelectric transducers for wireless communication and powering of sensors internal to the human body with a goal to transmit power levels of 100 W a receiver with receiving area of 3x3 mm2 over a distance of 16 cm equivalent to human body interior. The results suggest that we can transmit power levels that exceed this baseline requirement.

Jackson, Shannon↗
DOE OSTI2024

Comprehensive Comparative Analysis: VSI-based vs. CSI-based Motor Drive Systems with Sinusoidal Output Voltage

The emergence of wide-bandgap (WBG) power devices opens opportunities for current source inverters (CSIs) to provide a promising alternative drive configuration for motor drive applications. The sinusoidal output voltage of CSI offers significant advantages for numerous motor drive applications, including reducing the risks associated with motor terminal overvoltages and bearing discharge currents. This paper compares the performance of CSIs and voltage source inverters (VSIs) with the same performance capabilities. More specifically, sine filters are added to the VSI output terminals to match the CSI performance, and a front-end boost converter is added to the VSI to match the CSI’s voltage-boost capability. The results show that the CSI active components require 48% less volume than the VSI, combined with other performance advantages that make it an appealing candidate for some future motor drive applications.

current source inverter, motor drive system, passi↗
NASA NTRS1985

CU in space: The University of Colorado get away special payload G-285

The University of Colorado's first Get Away Special was conceived by a dozen science and engineering students in the spring of 1984. Since that time, the project has grown to include over 100 undergraduate and graduate students who have 'provided the experimental objectives, design, construction, integration, testing and management of the payload. Faculty and staff of the university and its affiliated laboratories as well as engineers from local industries have provided many useful suggestions at all stages of development. The principal motivation for developing this payload is to provide university students with the opportunity to participate in space science and engineering beginning at the ground level. At the same time, they are contributing their results from new science and technological discoveries to several disciplines. There are four separate experiments integrated into the /'single payload of G-285 which are supported by internal payload !power, thermal environment control, command land data handling [ facilities and structural subsystems. The four experiments contained in this payload are: a single spectrometer performing i two experiments- one to study night time shuttle glow phenomena in the ultraviolet and the other to observe NO2 concentrations over / equatorial latitudes in the day; a fluids management experiment ' using centrifugation for particle/liquid/vapor separation; and an experiment using Phycomyces fungi to study the gravireceptor mechanism theory. The experiments are supported by a microprocessor, data storage devices, power and thermal control subsystems. All these are located within a sealed aluminum container. The container, a refitted sounding rocket casing, has a top and bottom which bolt to the main body of the rocket section. The top section holds a five inch diameter quartz window through which light enters the spectrometer. A rotating mirror assembly and one of two battery boxes are mounted on the outside of the top section below the interface plane of the MDA. A second battery box is attached to the bottom section of the sealed container. All payload items except the battery boxes and mirror assembly are located inside the sealed rocket section to insure containment and to prevent outgassing of materials. The container will be sealed prior to launch and purged with one atmosphere of argon.

Kent Tobiska↗
NASA NTRS1993

Characterization and snubbing of a bidirectional MCT in a resonant ac link converter

The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive.

Lee, Tony↗
DOE OSTI2020

Optimization of barrier height in InGaN quantum wells for rapid interwell carrier transport and low nonradiative recombination

Rapid interwell carrier transport is a key process for a uniform carrier distribution and reduced Auger recombination in multiple quantum well (MQW) light emitting devices. In this work, the interwell transport has been studied by time-resolved photoluminescence in In 0.12 Ga 0.88 N MQWs with In x Ga 1–x N (x = 0 - 0.06) and Al 0.065 Ga 0.935 N barriers. Only for the InGaN barriers the transport is efficient. Furthermore, introduction of In into the barriers is accompanied by an increase of the nonradiative recombination at QW interfaces. Still, even with the increased Shockley–Read–Hall recombination, structures with InGaN barriers might be advantageous for high power devices because of the reduced Auger recombination.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Conceptual design of a high reactive-power ferroelectric fast reactive tuner

We present a novel design of a ferroelectric fast reactive tuner (FE-FRT) capable of modulating mega-VAR reactive power on a submicrosecond timescale. The high reactive power capability of our design extends the range of applications of reactive tuners to numerous applications. We present a detailed analytical model of the performance of a megawatt-class reactive power device and benchmark it against finite-element method eigenmode and frequency domain electromagnetic simulations. We introduce new features, including an annulus design for the ferroelectric capacitors and capacitive window coupling to the cavity. We consider thermal design issues and nonlinear effects in the ferroelectric. The model covers several configurations, allowing control of the frequency of superconducting and normal-conducting cavities in a variety of applications and frequencies. We calculate that the FE-FRT designed should be capable of handling around 0.45 MVAR of reactive power with around 3 kW of resistive losses, providing a frequency tuning range of 8 kHz in an example of 400 MHz cavity geometry. Published by the American Physical Society 2024

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Tuning Organic Electrochemical Transistor Threshold Voltage using Chemically Doped Polymer Gates

Organic electrochemical transistors (OECTs) have shown promise as transducers and amplifiers of minute electronic potentials due to their large transconductances. Tuning the OECT threshold voltage is important to achieve low-powered devices with amplification properties within the desired operational voltage range. However, traditional design approaches have struggled to decouple channel and materials properties from threshold voltage, thereby compromising on several other OECT performance metrics, such as electrochemical stability, transconductance, and dynamic range. In this work, simple solution-processing methods are utilized to chemically dope polymer gate electrodes, thereby controlling their work function, which in turn tunes the operation voltage range of the OECTs without perturbing their channel properties. Chemical doping of initially air-sensitive polymer electrodes further improves their electrochemical stability in ambient conditions. Thus, OECTs that are simultaneously low-powered and electrochemically resistant to oxidative side reactions under ambient conditions are demonstrated. Furthermore, this approach shows that threshold voltage, which is once interwoven with other OECT properties, can in fact be an independent design parameter, expanding the design space of OECTs.

chemical doping↗
DOE OSTI2020

Hawai‘i National Marine Renewable Energy Center (HINMREC)

The Hawaii National Marine Renewable Energy Center (HINMREC) was established to facilitate the commercialization of wave energy converter (WEC) devices, and to accelerate development and testing of Ocean Thermal Energy Conversion (OTEC) technologies. Housed at the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii (UH), this program started with execution of the contract between the US Department of Energy (DOE) and UH in March 2009, and activities ran through the end of the project in September 2019. The DOE tasked HINMREC with facilitating and accelerating the build-out of the Navy’s Wave Energy Test Site (WETS), the nation’s first grid-connected open water wave energy conversion test facility, located off Marine Corps Base Hawaii (MCBH) in Kaneohe, on the island of Oahu. WETS was expanded from an existing test berth at 30m water depth to include test berths at 60m and 80m water depths. In recognition of the high costs associated with at-sea testing and evaluation of WEC devices, it was deemed imperative that HINMREC seek ways to reduce costs to developers by providing key research support to these early-stage technologies. WETS and HINMREC’s support allowed development of wave energy technology by providing a testing infrastructure that allows technology developers to test, demonstrate and evaluate their WEC devices, and generate data in order to advance WEC designs toward commercial readiness. HINMREC’s roles have included support in the establishment of the full site, including of wave resource characterization and site survey, followed by the essential roles of independent WEC device power performance assessment and environmental monitoring in support of deployed pre-commercial WECs. This DOE-funded work transitioned effectively to continue Navy-funded tasks for OTEC development, and activities at WETS, now under Naval Facilities Engineering Command (NAVFAC) funding. A secondary objective in the establishment of HINMREC was to assist the private sector in moving OTEC systems beyond proof-of-concept to pre-commercialization, primarily focused on system and component engineering, and local and global investigations into the potential environmental impacts of OTEC systems. HINMREC was tasked with maintaining high-resolution models of ocean thermal resources and the potential sustainable power output of OTEC systems. Ongoing tests begun previously under Navy funding at the OTEC Heat Exchangers (HXs) Test Facility at the Natural Energy Laboratory of Hawaii Authority (NELHA), in Kona on Hawaii Island, have been continued to identify cost-effective aluminum alloys for use in OTEC systems operating in the corrosive marine environment.

16 TIDAL AND WAVE POWER↗
NASA NTRS1990

HgCdTe for NASA EOS missions and detector uniformity benchmarks

Important NASA Earth Observing System (EOS) missions, Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectrometer (MODIS-N), which require detector spectral response in the range of 14 to 17 microns at medium background flux levels and operation in the range of temperatures between 65 to 95 K, will be flown beginning in the next few years. Currently, a prime candidate detector technology for these missions is trapping-mode photoconductive HgCdTe devices. These devices can be tailored to the exact cutoff wavelengths required by those missions, and thus offer the performance advantages of an intrinsic detector which is ideally matched to the mission wavelength. Under the long wavelength-background-temperature conditions of these EOS missions, any detector will at best be thermal generation-recombination noise limited. Photoconductive devices are generally preferred under these circumstances, since at elevated temperatures their performance degrades with n(sub i) while for photovoltaic detectors performance degrades as n sub i(exp 2) n sub i is the intrinsic carrier concentration which is a function of alloy composition and temperature, but not doping. Very high performance trapping-mode photoconductive HgCdTe detectors have been developed which can be reproducibly fabricated. Detectivity (D asterisk) at 80K and 16 micron cutoff wavelength in excess of 10(exp 11) Jones has been measured for these devices. Power dissipation is at least two orders of magnitude less than conventional HgCdTe photoconductors - on the order of 0.12 W/cm(exp 2) compared with 12 W/cm(exp 2). EOS missions define thermal noise limited conditions for the long wavelength operating bands. Trapping-mode photoconductive HgCdTe detectors are linear under such conditions and responsivity is independent of background flux. At lower temperatures or high flux conditions in which background flux limits detector performance, trapping-mode detectors have a responsivity which varies with background flux. Internal calibration must be provided for radiometric measurements under the latter conditions (not an EOS mission concern). Liquid phase epitaxy is used to grow these HgCdTe device structures. This technique has been shown to give control of the cutoff wavelength on the order of 16 plus or minus 1 micron or less, both from run to run and across wafer dimensions of several centimeters on a side.

Norton, Paul R.↗
NASA NTRS2012

Design of an Ultra-Efficient GaN High Power Amplifier for Radar Front-Ends Using Active Harmonic Load-Pull

This work presents a new measurement technique, mixed-signal active harmonic load-pull (MSALP) developed by Anterverta-mw in partnership with Maury Microwave, that allows for wide-band ultra-high efficiency amplifiers to be designed using GaN technology. An overview of the theory behind active load-pull is presented and why load-pull is important for high-power device characterization. In addition, an example procedure is presented that outlines a methodology for amplifier design using this measurement system. Lastly, measured results of a 10W GaN amplifier are presented. This work aims to highlight the benefit of using this sophisticated measurement systems for to optimize amplifier design for real radar waveforms that in turn will simplify implementation of space-based radar systems

Active Load-pull↗
DOE OSTI2021

The coupling and competition of crystallization and phase separation, correlating thermodynamics and kinetics in OPV morphology and performances

The active layer morphology transition of organic photovoltaics under non-equilibrium conditions are of vital importance in determining the device power conversion efficiency and stability; however, a general and unified picture on this issue has not been well addressed. Using combined in situ and ex situ morphology characterizations, morphological parameters relating to kinetics and thermodynamics of morphology evolution are extracted and studied in model systems under thermal annealing. The coupling and competition of crystallization and demixing are found to be critical in morphology evolution, phase purification and interfacial orientation. A unified model summarizing different phase diagrams and all possible kinetic routes is proposed. The current observations address the fundamental issues underlying the formation of the complex multi-length scale morphology in bulk heterojunction blends and provide useful morphology optimization guidelines for processing devices with higher efficiency and stability.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Linking international technical specifications for acoustic characterization of marine energy converter sounds with environmental compliance criteria

As new ocean energy technologies emerge and are deployed for testing and operations, sound emissions are a potential concern for environmental effects to marine life. Consistent acoustic measurement and data analysis methods can help promote comparisons of technologies and transferability between project sites. In 2022, acoustic emissions from a prototype scale wave energy converter (WEC) were characterized for a range of environmental conditions and power generation states in the coastal waters off southern California using a set of international technical specifications. Results from the international technical specification analyses were applied to United States regulatory threshold criteria for acoustic impacts to marine mammals and examined in the context of European underwater noise monitoring guidelines. Weighted 24 hour cumulative sound exposure levels SEL24h calculated from the highest power generation state WEC sound pressure levels were often more than 20 dB below threshold criteria for temporary threshold shifts in five relevant marine mammal hearing groups. Following European Union recommendations for analyses and reporting, WEC sound characterization in third octave bands centered at 63 Hz and 125 Hz show clear spatial decay of WEC-generated noise, with more pronounced attenuation at 63 Hz, and a less marked but still detectable gradient at 125 Hz, collectively suggesting a relatively confined acoustic footprint under the observed conditions. The value of the international technical specification approach is highlighted by the isolation of WEC sounds from the surrounding soundscape. This allows for a robust characterization of acoustic emissions through a range of device power generation and sea states. Furthermore, in threshold-based regulatory contexts like the U.S., this facilitates direct evaluation of source contributions, while in broader monitoring frameworks used in the E.U. it provides a reproducible foundation for assessing the contribution of emerging ocean energy technologies to the underwater acoustic environment.

Haxel, Joseph H. (ORCID:0000000273864761)↗