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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 1,513 records · Page 84
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Logistics resupply scenario for the Space Station

The paper addresses an approach to developing an integrated scenario definition, operations considerations and hardware concepts development cycle that will provide the most effective set of concepts meeting Space Station logistics criteria. Attention is given to logistics system requirements sources, design package team involvement, requirements analysis and development, scenario development and evaluation, and logistics elements configuration. It is noted that the surviving set of integrated scenarios provided hardware and support requirements with built in discipline compliance and operational sensitivity.

Powell, L.↗
NASA NTRS1989

The dissociation energy of N2

The requirements for very accurate ab initio quantum chemical prediction of dissociation energies are examined using a detailed investigation of the nitrogen molecule. Although agreement with experiment to within 1 kcal/mol is not achieved even with the most elaborate multireference CI (configuration interaction) wave functions and largest basis sets currently feasible, it is possible to obtain agreement to within about 2 kcal/mol, or 1 percent of the dissociation energy. At this level it is necessary to account for core-valence correlation effects and to include up to h-type functions in the basis. The effect of i-type functions, the use of different reference configuration spaces, and basis set superposition error were also investigated. After discussing these results, the remaining sources of error in our best calculations are examined.

Almloef, Jan↗
NASA NTRS1989

The dissociation energy of N2

The requirements for very accurate ab initio quantum chemical prediction of dissociation energies are examined using a detailed investigation of the nitrogen molecule. Although agreement with experiment to within 1 kcal/mol is not achieved even with the most elaborate multireference CI (configuration interaction) wave functions and largest basis sets currently feasible, it is possible to obtain agreement to within about 2 kcal/mol, or 1 percent of the dissociation energy. At this level it is necessary to account for core-valence correlation effects and to include up to h-type functions in the basis. The effect of i-type functions, the use of different reference configuration spaces, and basis set superposition error were also investigated. After discussing these results, the remaining sources of error in our best calculations are examined.

Almlof, Jan↗
NASA NTRS1992

The spectral archive of cosmic X-ray sources observed by the Einstein Observatory Focal Plane Crystal Spectrometer

The Einstein Observatory Focal Plane Crystal Spectrometer (FPCS) used the technique of Bragg spectroscopy to study cosmic X-ray sources in the 0.2-3 keV energy range. The high spectral resolving power (E/Delta-E is approximately equal to 100-1000) of this instrument allowed it to resolve closely spaced lines and study the structure of individual features in the spectra of 41 cosmic X-ray sources. An archival summary of the results is presented as a concise record the FPCS observations and a source of information for future analysis by the general astrophysics community. For each observation, the instrument configuration, background rate, X-ray flux or upper limit within the energy band observed, and spectral histograms are given. Examples of the contributions the FPCS observations have made to the understanding of the objects observed are discussed.

Lum, Kenneth S. K.↗
NASA NTRS2005

Automation of Vapor-Diffusion Growth of Protein Crystals

Some improvements have been made in a system of laboratory equipment developed previously for studying the crystallization of proteins from solution by use of dynamically controlled flows of dry gas. The improvements involve mainly (1) automation of dispensing of liquids for starting experiments, (2) automatic control of drying of protein solutions during the experiments, and (3) provision for automated acquisition of video images for monitoring experiments in progress and for post-experiment analysis. The automation of dispensing of liquids was effected by adding an automated liquid-handling robot that can aspirate source solutions and dispense them in either a hanging-drop or a sitting-drop configuration, whichever is specified, in each of 48 experiment chambers. A video camera of approximately the size and shape of a lipstick dispenser was added to a mobile stage that is part of the robot, in order to enable automated acquisition of images in each experiment chamber. The experiment chambers were redesigned to enable the use of sitting drops, enable backlighting of each specimen, and facilitate automation.

Hamrick, David T.↗
NASA NTRS2018

Resonance and Tones in Dual-Stream Nozzle Flows

A dual-stream nozzle configuration was studied numerically with the objective of predicting the appearance of tones and study their sources. It was found that some of the tones traced to a coupling between Strouhal shedding from the struts, which held different pieces of the nozzle together, and various duct acoustic modes. A focus of the work was on exploring the nature of the duct modes. First, elements of the numerical procedure were studied for a 4-strut nozzle, validating the results with existing experimental data. The approach was then applied to a 3-strut geometry and four different excitation methods. The predicted tones and associated duct modes are analyzed in detail.

Milanovic, Ivana↗
NASA NTRS2014

Acoustic Measurements from Wind Tunnel Test of AMELIA - Advanced Model for Extreme Lift and Improved Aeroacoustics

A wind tunnel test has been conducted to measure the aerodynamic and acoustic performance of an active circulation-control aircraft with leading- and trailing- edge slot blowing. The 11 Advanced Model for Extreme Lift and Improved Aeroacoustics (AMELIA) model was tested in the Arnold Engineering Development Center (AEDC) National Full Scale Aerodynamics Complex (NFAC) 40- by 80-Ft wind tunnel. Forward velocities ranged from 0 to Mach 0.15 and total slot mass-flow was varied from 0 to 2.8 lbmsec. Angle-of-attack and sideslip ranges were -5 to 25 and -10 to 10, respectively.This reports summarizes acoustic measurements from the wind tunnel test and the corrections applied to the released acoustic data. The analysis focuses on measurements for the clean wing configuration (turbine propulsion simulators removed) with trailing-and leading-edge slot blowing and with trailing-edge blowing, for systematic variations in slot mass flow from nearly zero to the system maximum. The acoustic measurements from a fixed phased microphone array and seven fixed microphones were corrected for sensor directional response and atmospheric attenuation. Graphs of 13-octave spectra, narrowband spectra, and directional variations in OASPL are presented for each active lift configuration. This report is intended to document the corresponding set of corrected data that is now available for development and verification of new predictive models of the active lift source.For large slot mass flow conditions 13-octave spectral shapes were level and flat, typical of a pink noise source. Little source directivity was present in the OASPL levels for the 0 flap conditions and show only a slight downstream increase with the 60 flap configuration. For moderate to high slot mass flow conditions trailing-edge only blowing spectra were similar to leading- and trailing edge blowing cases. However for the lower mass flows variations of as much as 5 dB were observed.

CCW↗
NASA NTRS2019

Flight Performance Maneuver Planning for NASA’s X-57 “Maxwell” Flight Demonstrator – Part 1: Power-Off Glides

Distributed Electric Propulsion technology is expected to yield up to a fivefold increase in high-speed cruise efficiency for NASA’s X-57 “Maxwell” flight demonstrator when compared to a combustion-powered general aviation baseline. A portion of this increased efficiency is due to beneficial aero-propulsive interaction inherent to the distributed propulsion architecture. The measure of the relative increase in efficiency between a conventional and distributed propulsion wing will be extracted from comparisons between flight test data from the electrically powered X-57 Mod II configuration with a conventional wing, and from the electrically powered X-57 Mod III/IV configuration with a distributed propulsion wing. Flight test maneuvers that accommodate errors in instrumentation and the flight test environment are developed to establish the power-off drag characteristics for all X-57 configurations. Analysis of these maneuvers with typical errors, including pilot-in-the-loop simulation data that incorporates simulated atmospheric turbulence effects, shows that the proposed power-off flight maneuvers can generate accurate power-off drag predictions for the X-57. These predictions show that the power-off differences in aerodynamic performance between the conventional and distributed propulsion configurations can be accurately measured from flight test data in the presence of typical data error sources.

Borer, Nicholas K.↗
DOE OSTI2013

Mechanically-reattachable liquid-cooled cooling apparatus

An apparatus comprising a rack having a row of shelves, each shelf supporting an electronics circuit board, each one of the circuit boards being manually removable from the shelve supporting the one of the circuit boards and having a local heat source thereon. The apparatus also comprises a cooler attached to the rack and being able to circulate a cooling fluid around a channel forming a closed loop. The apparatus further comprises a plurality of heat conduits, each heat conduit being located over a corresponding one of the circuit boards and forming a path to transport heat from the local heat source of the corresponding one of the circuit boards to the cooler. Each heat conduit is configured to be manually detachable from the cooler or the circuit board, without breaking a circulation pathway of the fluid through the cooler.

42 ENGINEERING↗
DOE OSTI2018

Detector Backgrounds at the Higgs Factory Muon Collider: MARS $vs$ FLUKA

Simulations for the 125-GeV Higgs Factory (HF) Muon Collider (MC) have shown large background particle loads on the collider detector. To verify level, source and composition of background calculations were performed using FLUKA and MARS codes for two shielding configurations. After comprehensive tuning of muon beam parameters, geometry setups and scoring procedures, background particle distributions at the detector entrance were simulated and compared. The spatial distributions and energy spectra of background particles obtained by two codes are rather similar. Average numbers of background particles simulated using MARS and FLUKA agree within a factor of two.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Performance Baseline for Direct-Fired sCO2 Cycles

NETL has conducted an evaluation of the performance and emissions for a direct coal-fired supercritical CO2 (sCO2) power plant, which has recently received interest as a potentially lower-cost, fossil-fuelled power source with inherent amenability to carbon capture. This study describes a baseline coal-fired cycle configuration, where coal is first gasified and cleaned in order to avoid introducing sulfur and particulate matter into the sCO2 cycle, with the sCO2 cycle’s oxy-combustor operating on syngas. The baseline sCO2 plant design yields a net plant thermal efficiency of 37.7% (HHV), with 98.1% CO2 capture at 99.4% purity. This compares favorably to the reference IGCC plant, which has a 31.2% net HHV thermal efficiency, and 90.1% CO2 capture rate at 99.99% purity. The sensitivity of the sCO2 plant’s performance to its process variables is discussed, as well as their effect on plant operability and cost surrogate variables.

Shelton, Walter↗
DOE OSTI2016

Performance Baseline for Direct-Fired sCO2 Cycles

NETL has conducted an evaluation of the performance and emissions for a direct coal-fired supercritical CO2 (sCO2) power plant, which has recently received interest as a potentially lower-cost, fossil-fuelled power source with inherent amenability to carbon capture. This study describes a baseline coal-fired cycle configuration, where coal is first gasified and cleaned in order to avoid introducing sulfur and particulate matter into the sCO2 cycle, with the sCO2 cycle’s oxy-combustor operating on syngas. The baseline sCO2 plant design yields a net plant thermal efficiency of 37.7% (HHV), with 98.1% CO2 capture at 99.4% purity. This compares favorably to the reference IGCC plant, which has a 31.2% net HHV thermal efficiency, and 90.1% CO2 capture rate at 99.99% purity. The sensitivity of the sCO2 plant’s performance to its process variables is discussed, as well as their effect on plant operability and cost surrogate variables.

Weiland, Nathan↗
DOE OSTI2019

Technoeconomic Analysis of Nuclear-Renewable Hybrid Energy Systems - Opportunities, Learnings, and Challenges

Tightly coupled nuclear-renewable hybrid energy systems (N-R HESs) are designed to both generate dispatchable electricity and produce at least one industrial product from nuclear and renewable energy sources. This presentation summarizes findings from NREL's technoeonomic assessment of several N-R HES configurations. It summarizes key conclusions and communicates the next steps in NREL's work on these technologies.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2013

Active-to-Passive Environmental Cleanup Transition Strategies - 13220

The Savannah River Site uses a graded approach to environmental cleanup. The selection of groundwater and vadose zone remediation technologies for a specific contamination area is based on the size, contaminant type, contaminant concentration, and configuration of the plume. These attributes are the result of the nature and mass of the source of contamination and the subsurface characteristics in the area of the plume. Many large plumes consist of several zones that are most efficiently addressed with separate complementary corrective action/remedial technologies. The highest concentrations of contaminants are found in the source zone. The most robust, high mass removal technologies are often best suited for remediation of the source zone. In the primary plume zone, active remedies, such as pump-and-treat, may be necessary to remove contaminants and exert hydraulic control of the plume. In the dilute fringe zone, contaminants are generally lower in concentration and can often be treated with passive techniques. A key determination in achieving an acceptable and cost-effective end state for a given waste unit is when to transition from an active treatment system to a more passive or natural approach (e.g., monitored natural attenuation or enhanced attenuation). This paper will discuss the considerations for such a transition as well as provide examples of successful transitions at the Savannah River Site. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

The ICEBERG Test Stand for DUNE Cold Electronics Development

ICEBERG is a liquid argon time projection chamber at Fermilab for the purpose of testing detector components and software for the Deep Underground Neutrino Experiment (DUNE). The detector features a 1.15m x 1m anode plane following the specifications of the DUNE horizontal drift far detector and a newly installed X-ARAPUCA photodetector. The status of ICEBERG is reported along with analysis of noise, pulser, and cosmic ray data from the ninth run beginning May 2024 with the goal of advising the DUNE collaboration on the optimal wire readout electronics configuration. In addition, development of an absolute energy scale calibration method is currently underway using known sources such as cosmic ray muon Michel electrons at the ~10 MeV scale and $^{39}$Ar decay electrons at the ~100keV scale. Research into AI-based identification of such events at the data acquisition level is introduced.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

The EGS Collab Project – Stimulations at Two Depths

The EGS Collab project, supported by the US Department of Energy, is performing intensively monitored rock stimulation and flow tests at the 10-m scale in an underground research laboratory to address challenges in implementing enhanced geothermal systems (EGS). Data and observations from the field tests are compared to simulations to understand processes and build confidence in numerical modeling of the processes. We have completed Experiment 1 (of 3), which examined hydraulic fracturing in a well-characterized underground fractured phyllite test bed at a depth of approximately 1.5 km at the Sanford Underground Research Facility (SURF) in Lead, South Dakota. Testbed characterization included fracture mapping, borehole acoustic and optical televiewers, full waveform sonic, conductivity, resistivity, temperature, campaign p- and s-wave investigations and electrical resistance tomography. Borehole geophysical techniques including passive seismic, continuous active source seismic monitoring, electrical resistance tomography, fiber-based distributed strain, distributed temperature, and distributed acoustic monitoring, were used to carefully monitor stimulation events and flow tests. More than a dozen stimulations and nearly one year of flow tests were performed. Quality data and detailed observations were collected and analyzed during stimulation and water flow tests using ambient temperature and chilled water. We achieved adaptive control of the tests using real-time monitoring and rapid dissemination of data and near-real-time simulation. More detailed numerical simulation was performed to answer key experimental design questions, forecast fracture propagation trajectories and extents, and analyze and evaluate results. Data are freely available from the Geothermal Data Repository. Experiment 2 examines the potential for hydraulic shearing in amphibolite at a depth of about 1.25 km at SURF. This site has a different set of stress and fracture conditions than Experiment 1. The Experiment 2 testbed consists of nine subhorizontal boreholes configured in two fans of two boreholes which surround the testbed and contain grouted-in electrical resistance tomography, seismic sensors, active seismic sources and distributed fiber sensors. A “five-spot” set of test wells that extends from a custom mined alcove includes an injection well and four production/monitoring wells. The testbed was characterized geophysically and hydrologically, and three stimulations have been performed using the Step-Rate Injection Method for Fracture In-Situ Properties (SIMFIP) tool to measure strains, and a new strain quantifying tool (downhole robotic strain analysis tool -DORSA) was deployed in a monitoring hole during stimulation. Real-time data were broadcast during stimulations to allow real-time response to arising issues.

EGS Collab, Enhanced Geothermal Systems, EGS, fiel↗
NASA NTRS2006

Reducing Propulsion Airframe Aeroacoustic Interactions With Uniquely Tailored Chevrons: 3. Jet-Flap Interaction

Propulsion airframe aeroacoustic (PAA) interactions, resulting from the integration of engine and airframe, lead to azimuthal asymmetries in the flow/acoustic field, e.g., due to the interaction between the exhaust jet flow and the pylon, the wing and its high-lift devices, such as, flaps and flaperons. In the first two parts of this series we have presented experimental results which show that isolated and installed nozzles with azimuthally varying chevrons (AVCs) can reduce noise more than conventional chevrons when integrated with a pylon and a wing with flaps at take-off conditions. In this paper, we present model-scale experimental results for the reduction of jet-flap interaction noise source due to these AVCs and document the PAA installation effects (difference in noise between installed and isolated nozzle configurations) at both approach and take-off conditions. It is found that the installation effects of both types of chevron nozzles, AVCs and conventional, are reversed at approach and take-off, in that there is more installed noise reduction at approach and less at take-off compared to that of the isolated nozzles. Moreover, certain AVCs give larger total installed noise benefits at both conditions compared to conventional chevrons. Phased microphone array results show that at approach conditions (large flap deflection, low jet speed and low ambient Mach number), chevrons gain more noise benefit from reducing jetflap interaction noise than they do from quieting the jet plume noise source which is already weak at these low jet speeds. In contrast, at take-off (small flap deflection, high jet speed and high ambient Mach number) chevrons reduce the dominant jet plume noise better than the reduction they create in jet-flap interaction noise source. In addition, fan AVCs with enhanced mixing near the pylon are found to reduce jet-flap interaction noise better than conventional chevrons at take-off.

Thomas, Russ H.↗
DOE OSTI2024

Research and Development to Reduce Impurity Production and Transport of the Impurities to the Target in Linear Plasma Devices Using Helicon Plasma Sources

Linear plasma devices used to test plasma facing materials (PFMs) and components for fusion reactors are often suffering under the production of intrinsic impurities from the plasma source system. Most linear plasma devices use internal electrodes (hollow cathodes, reflex arc, or cascading arc), which typically are the source of the main impurities. The next-generation plasma generators use radio frequency (RF) plasma sources like helicons to avoid internal electrodes. However, high power operation of helicons has proven to result in impurity production due to the high rectified sheath voltages created. Depending on the plasma parameters and magnetic configuration, these impurities can be transported to the target and deposited there to unacceptable high levels. Here, in this contribution, the experimental results from Proto-MPEX are summarized, and the conclusions of the impurity source physics are given. Methods to reduce the impurity production, the impurity transport, and the net deposition on the target are presented. These methods to reduce the impurity production include Faraday screens to reduce the sheath voltage drop, high-Z refractory coatings to reduce the erosion yield, and wall conditioning methods. Methods to reduce the impurity transport include changes in the magnetic configuration as well as electron heating to change axial and radial temperature profiles. Preliminary results on the effectiveness of some of these methods are presented.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗