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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Highly Integrated Wide Bandgap Power Module for Next Generation Plug-In Vehicles (Final Report)

Wide bandgap devices are key enablers for high power density traction inverters. A highly integrated wide bandgap (WBG) power module enables higher temperature operation, higher inverter efficiency and overall smaller die area with the same power delivery. However, it requires careful design of the power module to take advantage of all the superior material properties that silicon carbide (SiC) provides over conventional silicon (Si) Insulated Gate Bipolar Transistor (IGBT) based design. This project developed an efficient and densely packed SiC power module for an automotive traction inverter application. Extensive study was performed to select the best performing SiC die considering a wide range of temperature variation, suitability to integrate into target packaging, robust body diode performance and overall high electrical efficiency. Multiple design ideas were explored to achieve lower stray inductance for both power loop and signal loop, uniform current distribution, compact form factor, and very high thermal performance. The final power module package includes all six inverter switches in the same module (six-pack) with die sintered at both bottom and top surfaces utilizing high performance substrate to achieve high electrical and thermal performance. Two power module variants were developed using 900 V and 1200 V devices for operating at two different high voltage levels (> 600 V HV battery). Both power modules were comprehensively characterized, and high efficiency operation of the inverter was confirmed through analysis. Finally, a complete functional inverter was built with the 1200V power modules using other essential components (HV capacitors, gate driver board, controller board, current sensor, connectors etc.) and tested using GM’s standard test procedure. There are several challenges associated with adopting WBG devices for high voltage operation. In order to assess and mitigate those challenges, GM and subrecipients of this project have conducted multiple detailed studies. This includes phase current reconstruction using integrated Rogowski coil, device junction temperature estimation using on-state gate resistance, modeling and testing the effect of high voltage and fast switching on motor insulation and bearings, partial discharge inception voltage measurement under different environmental conditions. Findings of all these studies are summarized in this report.

33 ADVANCED PROPULSION SYSTEMS↗
NASA NTRS1990

Fiber optic sensors IV; Proceedings of the Third European Congress on Optics, The Hague, Netherlands, Mar. 13, 14, 1990

Recent advances in fiber-optic sensor (FOS) technology are examined in reviews and reports. Sections are devoted to components for FOSs, special fibers for FOSs, interferometry, FOS applications, and sensing principles and influence. Particular attention is given to solder glass sealing technology for FOS packaging, the design of optical-fiber current sensors, pressure and temperature effects on beat length in highly birefringent optical fibers, a pressure FOS based on vibrating-quartz-crystal technology, remote sensing of flammable gases using a fluoride-fiber evanescent probe, a displacement sensor with electronically scanned white-light interferometer, the use of multimode laser diodes in low-coherence coupled-cavity interferometry, electronic speckle interferometry compensated for environmentally induced phase noise, a dual-resolution noncontact vibration and displacement sensor based on a two-wavelength source, and fiber optics in composite materials.

Kersten, Ralf T.↗
NASA NTRS1986

Measuring Continuous-Path Accuracies of Robots

Sensors yield data on deviation from predetermined path and speed. Accuracy and repeatability of continuous-path robot motion measured with new method. Determines ability of robot to maintain tool orientation. Used with any type of manipulator arm and with separate, coordinated part positioner. Noncontacting eddy-current sensors measure distance from tool to aluminum path plate as robot end effector moves tool at prescribed distance from plate. Flat, sloped, curved, and other shapes used for path plate.

Allison, T. A.↗
NASA NTRS1980

Space applications of superconductivity - Low frequency superconducting sensors

Although this paper deals with several low-frequency instruments and devices, most of the discussion relates to SQUID (Superconducting QUantum Interference Device) magnetometers and gradiometers, since these are perceived as the instruments with the greatest potential for space applications. The discussion covers SQUID for magnetic field measurements; present state of the art of SQUID technology; ultimate potential performance; applications to magnetic measurements in space; SQUID galvanometers, voltage and current sensors, and wide-band amplifiers; magnetic shielding, and superconducting dc transformer. SQUIDS are superior to all other magnetic sensors in sensitivity, frequency response, range, and linearity. It is suggested that SQUID instruments, both magnetometers and gradiometers, would be valuable in studies of the dynamics of interplanetary and planetary fields. SQUID gradiometers are useful for detection and mapping of magnetic anomalies at short to moderate ranges.

Zimmerman, J. E.↗
NASA NTRSDate not supplied

Tracking 2020 Decreases in Carbon Dioxide Due to the COVID19 Pandemic in NASA’s GEOS Modeling system: Implications for Space-Based Carbon Monitoring

The COVID19 pandemic led to abrupt, worldwide changes in human activity and related emissions of air pollutants and greenhouse gases that are unprecedented in modern times. NASA satellites have demonstrated their ability to observe some of these impacts, particularly in relation to short-lived gases like nitrogen dioxide (NO2), which is emitted primarily from transportation. Bottom-up analyses of carbon dioxide (CO2) emissions suggest that the growth of atmospheric CO2 has also slowed, but differences are much more subtle than for NO2 because of the lifetime of atmospheric CO2 and sectoral differences in emission reductions. Estimates of CO2 from NASA’s Orbiting Carbon Observatory 2 (OCO-2) provide a unique view of COVID19 impacts, but observed changes in the column-average CO2 can be difficult to interpret because of gaps in spatial coverage. Assimilating these data into the Goddard Earth Observing System (GEOS), an integrated Earth system model with an advanced Constituent Data Assimilation System (CoDAS), helped to reveal changes in CO2 that are consistent with separate, bottom-up analyses of emissions reductions. Both indicate that from February-April of 2020, the growth in CO2 over Europe, North America, and Asia was roughly 0.3 ppm less than during the previous four years. Anomalies derived from gap-filled GEOS OCO-2 CoDAS products contribute to a joint effort by the world’s space agencies to track COVID19 impacts on the Earth. However, attribution of these changes is complicated by interannual variability in atmospheric circulation and the influence of climate on ocean and land carbon sinks. We discuss these results from the perspective of space-based carbon monitoring, which has received considerable support over the past decade from NASA. Our results demonstrate the accomplishments of current sensors and data assimilation systems, but also highlight challenges in providing high quality, low latency information to the public. In particular, understanding and attributing CO2 changes during 2020 requires year-specific information about land and ocean fluxes, which is often delayed for months or even years. We discuss current limitations and potential solutions to address these lags, which would support more reliable and timely space-based carbon monitoring.

COVID-19↗
NASA NTRS2012

Evaluation of the Performance Characteristics of CGLSS II and U.S. NLDN Using Ground-Truth Data from Launch Complex 398, Kennedy Space Center, Florida

A new comprehensive lightning instrumentation system has been designed for Launch Complex 39B (LC39B) at the Kennedy Space Center, Florida. This new instrumentation system includes six synchronized high-speed video cameras, current sensors installed on the nine downcouductors of the new lightning protection system (LPS) for LC39B; four dH/dt, 3-axis measurement stations; and five dE/dt stations composed of two antennas each. The LPS received 8 direct lightning strikes (a total of 19 strokes) from March 31 through December 31, 2011. The measured peak currents and locations are compared to those reported by the CGLSS 11 and the NLDN. Results of comparison are presented and analyzed in this paper.

Mata, Carlos T.↗
NASA NTRS2012

Evaluation of the Performance Characteristics of CGLSS II and U.S. NLDN Using Ground-Truth Dalta from Launch Complex 398, Kennedy Space Center, Florida

A new comprehensive lightning instrumentation system has been designed for Launch Complex 39B (LC39B) at the Kennedy Space Center, Florida. This new instrumentation system includes seven synchronized high-speed video cameras, current sensors installed on the nine downconductors of the new lightning protection system (LPS) for LC39B; four dH/dt, 3-axis measurement stations; and five dE/dt stations composed of two antennas each. The LPS received 8 direct lightning strikes (a total of 19 strokes) from March 31 through December 31 2011. The measured peak currents and locations are compared to those reported by the Cloud-to-Ground Lightning Surveillance System (CGLSS II) and the National Lightning Detection Network (NLDN). Results of comparison are presented and analyzed in this paper.

Mata, C. T.↗
NASA NTRS2014

Lightning Current Measurement with Fiber-Optic Sensor

A fiber-optic current sensor is successfully developed with many potential applications for electric current measurement. Originally developed for in-flight lightning measurement, the sensor utilizes Faraday Effect in an optical fiber. The Faraday Effect causes linear light polarization in a fiber to rotate when the fiber is exposed to a magnetic field. The polarization change is detected using a reflective polarimetric scheme. Forming fiber loops and applying Ampere's law, measuring the total light rotation results in the determination of the total current enclosed. The sensor is conformable to complex structure geometry. It is also non-conductive and immune to electromagnetic interference, saturation or hysteresis. Installation is non-intrusive, and the sensor can be safely routed through flammable areas. Two similar sensor systems are described in this paper. The first system operates at 1310nm laser wavelength and is capable of measuring approximately 300 A - 300 kA, a 60 dB range. Laboratory validation results of aircraft lighting direct and in-direct effect current amplitudes are reported for this sensor. The second system operates at 1550nm wavelength and can measure about 400 A - 400 kA. Triggered-lightning measurement data are presented for this system. Good results are achieved in all cases.

Nguyen, Truong X.↗
NASA NTRS2017

The Potential for Health Monitoring in Expandable Space Modules: The Bigelow Expandable Activity Module on the ISS

Expandable modules for use in space and on the Moon or Mars offer a great opportunity for volume and mass savings in future space exploration missions. This type of module can be compressed into a relatively small shape on the ground, allowing them to fit into space vehicles with a smaller cargo/fairing size than a traditional solid, metallic structure based module would allow. In April 2016, the Bigelow Expandable Activity Module (BEAM) was berthed to the International Space Station (ISS). BEAM is the first human-rated expandable habitat/module to be deployed and crewed in space. BEAM is a NASA managed ISS payload project in partnership with Bigelow Aerospace. BEAM is intended to stay attached to ISS for an operational period of 2 years to help advance the technology readiness for future expandable modules. BEAM has been instrumented with a suite of space flight certified sensors systems which will help characterize the module's performance for thermal, radiation shielding and impact monitoring against potential Micro Meteoroid/Orbital Debris (MM/OD) providing fundamental information on the BEAM environment for potential health monitoring requirements and capabilities. This paper will provide an overview of how the sensors/instrumentation systems were developed, tested, installed and an overview of the current sensor system operations. It will also discuss how the MM/OD impact detection system referred to as the Distributed Impact Detection System (DIDS) data is being processed and reviewed on the ground by the principle investigators.

Wells, Nathan D.↗
NASA NTRS2003

Magnetic Bearing Controller Improvements for High Speed Flywheel System

A magnetic bearing control system for a high-speed flywheel system is described. The flywheel utilizes a five axis active magnetic bearing system, using eddy current sensors for position feedback to the bearing controller. Magnetic bearing controller features designed to improve flywheel operation and testing are described. Operational improvements include feed forward control to compensate for rotor imbalance, moving notch filtering to compensate for synchronous and harmonic rotational noise, and fixed notching to prevent rotor bending mode excitation. Testing improvements include adding safe gain, bearing current hold, bearing current zero, and excitation input features. Performance and testing improvements provided by these features are measured and discussed.

Dever, Timothy P.↗
DOE OSTI2025

Combining quantum noise reduction resources: A practical approach

Optomechanical sensors are capable of transducing external perturbations to resolvable optical signals. A particular regime of interest is that of high-bandwidth force detection, where an impulse is delivered to the system over a short period of time. Exceedingly sensitive impulse detection has been proposed to observe very weak signals like those due to long-range interactions with dark matter that require much higher sensitivities than current sensors can provide. Quantum resources to go beyond the traditional standard quantum limit of these sensors include squeezing of the light used to transduce the signal, backaction evasion by measuring the optimal quadrature, and quantum nondemolition (QND) measurements that reduce backaction directly. These methods have been developed in the context of gravitational wave detection for target frequencies in the audio band range. Here, we provide the theoretical limits to quantum noise reduction for higher and broader frequency targets, such as those from dark matter signals, while combining quantum-enhanced readout techniques based on squeezed light and QND measurements with optomechanical sensors. Here, we demonstrate that backaction evasion through QND techniques dramatically reduces the technical challenges presented when using squeezed light for broadband force detection, paving the way for combining multiple quantum noise reduction techniques for enhanced sensitivity in the context of impulse metrology.

Optomechanics↗
NASA NTRS1985

Position Paper: Workshop on Geologic Applications of Remote Sensing to the Study of Sedimentary Basins

The utility of LANDSAT Multispectral Scanner (MSS) and Thematic Mapper (TM) data for providing regional coverage has been demonstrated. Information derived from LANDSAT spectral data is varied, but has primarily been used for distinguishing materials in a scene. Because of the limited number and width of the MSS and TM bands, LANDSAT data has only limited utility for actual identification of materials. The new advanced sensors (currently airborne, but eventually shuttle-based) have more limited areal extent than LANDSAT, but greater spatial and spectral resolution. The Airborne Imaging Spectrometer (AIS) has spectral resolution of about .01 microns and, typically, has 10m/pixel spatial resolution. This improved spectral resolution means that diagnostic spectral features may now be identified, which in turn means that actual identification of mineral phases present can be addressed (of either monominerallic or composite materials). Another new sensor, the Thermal Infrared Multispectral Scanners (TMS), obtains data in the 8 to 12 micron range. The information from the various sensors (e.g., LANDSAT, AIS, and TIMS) is complementary, covering different wavelength regions and consequently sensitive to different materials or physical properties of materials. In addition, the new sensors also produce a higher volume of data, which must be cleverly and efficiently handled.

Blake, P. L.↗
NASA NTRS2013

Dual-Polarization, Multi-Frequency Antenna Array for use with Hurricane Imaging Radiometer

Advancements in common aperture antenna technology were employed to utilize its proprietary genetic algorithmbased modeling tools in an effort to develop, build, and test a dual-polarization array for Hurricane Imaging Radiometer (HIRAD) applications. Final program results demonstrate the ability to achieve a lightweight, thin, higher-gain aperture that covers the desired spectral band. NASA employs various passive microwave and millimeter-wave instruments, such as spectral radiometers, for a range of remote sensing applications, from measurements of the Earth's surface and atmosphere, to cosmic background emission. These instruments such as the HIRAD, SFMR (Stepped Frequency Microwave Radiometer), and LRR (Lightweight Rainfall Radiometer), provide unique data accumulation capabilities for observing sea surface wind, temperature, and rainfall, and significantly enhance the understanding and predictability of hurricane intensity. These microwave instruments require extremely efficient wideband or multiband antennas in order to conserve space on the airborne platform. In addition, the thickness and weight of the antenna arrays is of paramount importance in reducing platform drag, permitting greater time on station. Current sensors are often heavy, single- polarization, or limited in frequency coverage. The ideal wideband antenna will have reduced size, weight, and profile (a conformal construct) without sacrificing optimum performance. The technology applied to this new HIRAD array will allow NASA, NOAA, and other users to gather information related to hurricanes and other tropical storms more cost effectively without sacrificing sensor performance or the aircraft time on station. The results of the initial analysis and numerical design indicated strong potential for an antenna array that would satisfy all of the design requirements for a replacement HIRAD array. Multiple common aperture antenna methodologies were employed to achieve exceptional gain over the entire spectral frequency band while exhibiting superb VSWR (voltage standing wave ratio) values. Element size and spacing requirements were addressed for a direct replacement of the thicker, lower-performance, stack ed patch antenna array currently employed for the HIRAD application. Several variants to the multiband arrays were developed that exhibited four, equally spaced, high efficiency, "sweet spot" frequency bands, as well as the option for a high-performance wideband array. The 0.25-in. (≈6.4- mm) thickness of the antenna stack-up itself was achieved through the application of specialized antenna techniques and meta-materials to accomplish all design objectives.

Little, John↗
NASA NTRS2010

Kennedy Space Center's Partnership with Graftel Incorporated

NASA Kennedy Space Center (KSC) has recently partnered with Graftel Incorporated under an exclusive license agreement for the manufacture and sale of the Smart Current Signature Sensor. The Smart Current Signature Sensor and software were designed and developed to be utilized on any application using solenoid valves. The system monitors the electrical and mechanical health of solenoids by comparing the electrical current profile of each solenoid actuation to a typical current profile and reporting deviation from its learned behavior. The objective of this partnership with Graftel is for them to develop the technology into a hand-held testing device for their customer base in the Nuclear Power Industry. The device will be used to perform diagnostic testing on electromechanical valves used in Nuclear Power plants. Initially, Graftel plans to have working units within the first year of license in order to show customers and allow them to put purchase requests into their next year's budget. The subject technology under discussion was commercialized by the Kennedy Space Center Technology Programs and Partnerships Office, which patented the technology and licensed it to Graftel, Inc., a company providing support, instrumentation, and calibration services to the nuclear community and private sector for over 10 years. For the nuclear power industry, Graftel designs, manufacturers, and calibrates a full line of testing instrumentation. Grafters smart sensors have been in use in the United States since 1993 and have proved to decrease set-up time and test durations. The project was funded by Non-Destructive Engineering, and it is felt that this technology will have more emphasis on future vehicles. Graftel plans to market the Current Signature Sensor to the Electric Utility industry. Graftel currently supplies product and services to the Nuclear Power Industry in the United States as well as internationally. Product and services sold are used in non-destructive testing for valves, penetrations and other applications. Graftel also supplies testing services to an industrial customer base. The customer base includes 90 percent of the U.S. Nuclear plants and plants in Brazil, Europe, and Asia. Graftel works internationally with two representative groups and employees and has ten people at the principle location and a group of contract engineers around the country.

Dunn, Carol Anne↗
DOE OSTI2022

Simulating self-powered neutron detector responses to infer burnup-induced power distribution perturbations in next-generation light water reactors

Understanding how 3D power distribution will be monitored throughout reactor core volumetric space in next-generation nuclear power reactors is crucial to the design, deployment, and licensing of these reactors. Although numerous techniques exist for 3D power distribution monitoring based on the response of both in situ and ex situ sensors currently implemented or proposed for use in the US reactor fleet, crucial details about these techniques are often unclear. The publicly available documentation does not include information such as how well these techniques are characterized and optimized in their implementations and the levels of uncertainty in the inferred 3D power distribution. The work described herein investigated a recently developed 3D power distribution inferencing method as applied to two next-generation reactor simulations: (1) the NuScale small modular reactor design and (2) the Westinghouse AP1000 design, both of which contain in-core strings of vanadium self-powered neutron detectors (SPNDs). This investigation considered a range of SPND string sensor densities, as well as a range of 3D power distribution axial segment sizes. In this work, SPND response simulation is informed by neutron flux calculations in representative homogenized cores. For the different sensor densities and power distribution axial segment sizes in these simulations, the average solution error, solver iterations, and run time were tracked to parameterize the sensor-core configuration.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS2004

Next Generation Geostationary Operational Environmental Satellite (GOES-R Series): A Space Segment Overview

The next-generation National Oceanic and Atmospheric Administration (NOAA) Geostationary Operational Environmental Satellite (GOES-R series) is currently being developed by NOAA in cooperation with the National Aeronautics and Space Administration (NASA). The GOES-R series satellites represents a significant improvement in spatial, temporal, and spectral observations (several orders of magnitude) over the capabilities of the currently operational GOES-1 series and the about to be launched GOES-N series satellite. The GOES-R series will incorporate technically advanced third-generation instruments and spacecraft enhancements to meet evolving observational requirements of forecasting for the era 2012-2025. The GOES-R instrument complement being developed includes a Advanced Baseline Imager (ABI), a Hyperspectral Environmental Suite (HES), a GEO Lighting Mapper (GLM), a Solar Imaging Suite (SIS) and a Space Environment In-Situ Suite (SEISS). Also, candidates for a number of GOES-R Pre-Planned Product Improvements (P(sup 3)Is) includes a Geo microwave Sounder, a Coronograph, a Hyperspectral Imager, and a Solar Irradiance Sensor. Currently, the GOES-R Space Segment architecture is being evaluated as part of a GOES-R system end-to-end architecture study. The GOES-R notional baseline architecture is a constellation of two satellites (A-sat and B-sat) each nominally located at 75 degrees west longitude and at 135 degrees west longitude at geostationary altitude, 0 degrees inclination. The primary mission of the A-sat is to provide imaging from the ABI. The A-sat will also contain the SIS and the GLM. The primary mission of the B-sat is to provide sounding of the hemispherical disk of the earth from the HES. The B-sat also contains the SEISS. Both satellites have mesoscale capabilities for severe weather sounding or imaging. This paper overviews the GOES-R Space Segment development including satellite constellation trade-off, improvements and differences between the current and future instrument and spacecraft capabilities, and technology infusion.

Krimchansky, Alexander↗
NASA NTRS1982

Current status of visibility sensors for aviation

The development of a new increased range higher visibility was investigated. The visibility sensor that is currently is the Transmissometer. Current transmissometer technology provides only a factor of 10 dynamic range with a single base line. The FAA is preparing to install automated weather observing systems (AWOS) at many locations. These systems require visibilities up to approximately 5 miles. To use a transmissometer for this type of measurement, the base line must be about 1,000 feet; where alignment becomes very difficult to maintain. New technologies were developd for measuring visibility. Improved transmissometers, forward-scatter meters and back-scatter meters have become available. A current practical issue for visibility sensors is how to specify one that is good enough to meet the needs of aviation. The first question is what performance is required; how accurately must the sensor measure? Visibility sensors do not actually measure the visibility directly. The purpose of measuring the visibility is to predict what the pilot will see a considerable distance away from the sensor location. The atmosphere introduces considerable variation in the measurement and the basic sensor accuracy needed is difficult to define. The second question for high visibilities is what to use as the standard reference sensor. The third question pertains to the competitive procurement of visibility sensors, which is mandated at present. Two acceptance test procedures to be used to insure satisfactory sensor performance is examined.

David C. Burnham↗
NASA NTRS2012

Single Pixel Characterization of X-Ray TES Microcalorimeter Under AC Bias at MHz Frequencies

In this paper we present the progress made at SRON in the read-out of GSFC x-ray transition-edge sensor (TES) micro-calorimeters in the frequency domain. The experiments reported so far, whose aim was to demonstrate an energy resolution of 2eV at 6 keV with a TES acting as a modulator, were carried out at frequencies below 700 kHz using a standard flux locked loop (FLL) SQUID read-out scheme. The TES read-out suffered from the use of sub-optimal circuit components, large parasitic inductances, low quality factor resonators and poor magnetic field shielding. We have developed a novel experimental set-up, which allows us to test several read-out schemes in a single cryogenic run. In this set-up, the TES pixels are coupled via superconducting transformers to 18 high-Q lithographic LC filters with resonant frequencies ranging between 2 and 5 MHz. The signal is amplified by a two-stage SQUID current sensor and baseband feedback is used to overcome the limited SQUID dynamic range. We study the single pixel performance as a function of TES bias frequency, voltage and perpendicular magnetic field.

Gottardi, L.↗