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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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Solid rocket booster performance evaluation model. Volume 1: Engineering description

The space shuttle solid rocket booster performance evaluation model (SRB-II) is made up of analytical and functional simulation techniques linked together so that a single pass through the model will predict the performance of the propulsion elements of a space shuttle solid rocket booster. The available options allow the user to predict static test performance, predict nominal and off nominal flight performance, and reconstruct actual flight and static test performance. Options selected by the user are dependent on the data available. These can include data derived from theoretical analysis, small scale motor test data, large motor test data and motor configuration data. The user has several options for output format that include print, cards, tape and plots. Output includes all major performance parameters (Isp, thrust, flowrate, mass accounting and operating pressures) as a function of time as well as calculated single point performance data. The engineering description of SRB-II discusses the engineering and programming fundamentals used, the function of each module, and the limitations of each module.

Source record↗
DOE OSTI2016

Preliminary Analysis of the General Performance and Mechanical Behavior of Irradiated FeCrAl Base Alloys and Weldments

The iron-based, iron-chromium-aluminum (FeCrAl) alloys are promising, robust materials for deployment in current and future nuclear power plants. This class of alloys demonstrates excellent performance in a range of environments and conditions, including high-temperature steam (>1000°C). Furthermore, these alloys have the potential to have prolonged survival under loss-of-coolant accident (LOCA) conditions compared to the more traditional cladding materials that are either Zr-based alloys or austenitic steels. However, one of the issues associated with FeCrAl alloys is cracking during welding. The present project investigates the possibility of mitigating welding-induced cracking via alloying and precise structure control of the weldments; in the frame work of the project, several advanced alloys were developed and are being investigated prior to and after neutron irradiation to provide insight into the radiation tolerance and mechanical performance of the weldments. The present report provides preliminary results on the post-irradiation characterization and mechanical tests performed during United States Fiscal Year (FY) 2016. Chapter 1 provides a general introduction, and Chapter 2 describes the alloy compositions, welding procedure, specimen geometry and manufacturing parameters. Also, a brief discussion of the irradiation at the High Flux Isotope Reactor (HFIR) is provided. Chapter 3 is devoted to the analysis of mechanical tests performed at the hot cell facility; tensile curves and mechanical properties are discussed in detail focusing on the irradiation temperature. Limited fractography results are also presented and analyzed. The discussion highlights the limitations of the testing within a hot cell. Chapter 4 underlines the advantages of in-situ testing and discusses the preliminary results obtained with newly developed miniature specimens. Specimens were moved to the Low Activation Materials Development and Analysis (LAMDA) laboratory and prepared for mechanical tests. Tensile tests were conducted at LAMDA using a modern digital image correlation approach allowing for strain distribution analysis. Plastic strain initiation and necking are discussed in detail; a concept of strain rate maps is also introduced and discussed. Follow-on SEM-EBSD and FIBTEM analysis is planned.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
NASA NTRS2001

Issues Related to Cleaning Complex Geometry Surfaces with ODC-Free Solvents

Implementing ozone depleting chemicals (ODC)-free solvents into full-scale reusable solid rocket motor cleaning operations has presented problems due to the low vapor pressures of the solvents. Because of slow evaporation, solvent retention is a problem on porous substrates or on surfaces with irregular geometry, such as threaded boltholes, leak check ports, and nozzle backfill joints. The new solvents are being evaluated to replace 1,1,1-trichloroethane, which readily evaporates from these surfaces. Selection of the solvents to be evaluated on full-scale hardware was made based on results of subscale tests performed with flat surface coupons, which did not manifest the problem. Test efforts have been undertaken to address concerns with the slow-evaporating solvents. These concerns include effects on materials due to long-term exposure to solvent, potential migration from bolthole threads to seal surfaces, and effects on bolt loading due to solvent retention in threads. Tests performed to date have verified that retained solvent does not affect materials or hardware performance. Process modifications have also been developed to assist drying, and these can be implemented if additional drying becomes necessary.

Bradford, Blake F.↗
NASA NTRS2002

A New Forced Oscillation Capability for the Transonic Dynamics Tunnel

A new forced oscillation system has been installed and tested at NASA Langley Research Center's Transonic Dynamics Tunnel (TDT). The system is known as the Oscillating Turntable (OTT) and has been designed for the purpose of oscillating, large semispan models in pitch at frequencies up to 40 Hz to acquire high-quality unsteady pressure and loads data. Precisely controlled motions of a wind-tunnel model on the OTT can yield unsteady aerodynamic phenomena associated with flutter, limit cycle oscillations, shock dynamics, and non-linear aerodynamic effects on many vehicle configurations. This paper will discuss general design and components of the OTT and will present test data from performance testing and from research tests on two rigid semispan wind-tunnel models. The research tests were designed to challenge the OTT over a wide range of operating conditions while acquiring unsteady pressure data on a small rectangular supercritical wing and a large supersonic transport wing. These results will be presented to illustrate the performance capabilities, consistency of oscillations, and usefulness of the OTT as a research tool.

Piatak, David J.↗
NASA NTRS1979

Static test-stand performance of the YF-102 turbofan engine with several exhaust configurations for the Quiet Short-Haul Research Aircraft (QSRA)

The performance of a YF-102 turbofan engine was measured in an outdoor test stand with a bellmouth inlet and seven exhaust-system configurations. The configurations consisted of three separate-flow systems of various fan and core nozzle sizes and four confluent-flow systems of various nozzle sizes and shapes. A computer program provided good estimates of the engine performance and of thrust at maximum rating for each exhaust configuration. The internal performance of two different-shaped core nozzles for confluent-flow configurations was determined to be satisfactory. Pressure and temperature surveys were made with a traversing probe in the exhaust-nozzle flow for some confluent-flow configurations. The survey data at the mixing plane, plus the measured flow rates, were used to calculate the static-pressure variation along the exhaust nozzle length. The computed pressures compared well with experimental wall static-pressure data. External-flow surveys were made, for some confluent-flow configurations, with a large fixed rake at various locations in the exhaust plume.

Mcardle, J. G.↗
NASA NTRS1973

Feasibility model of a high reliability five-year tape transport, volume 2

Analysis of the design features of the modularized tape transport renders a life expectancy in excess of five years. Tests performed on the tape transport were directed toward determining its performance capability. These tests revealed that the tape jitter and skew are in the range achieved by high quality digital tape transports. Guidance of the tape in the lateral sense by the use of the two hybrid crowned rollers proved to be excellent. Tracking was maintained within less than one thousandth inch (approximately 2 micrometers). The guidance capability demonstrated makes possible the achievement of the performance objective of 7.2 x 10 to the 9th power storage capability employing 1500 ft. of one inch wide tape with a packing density of 5,000 bits per inch per track on 80 tracks. Also, the machine showed excellent characteristics operating over a wide range of tape speeds. The basic design concept lends itself to growth and adaptation to a wide range of recorder requirements.

Eshleman, R. L.↗
NASA NTRS1995

High-Temperature/Vacuum Fiber-Pushout Apparatus

Fiber-pushout tests performed at temperatures up to 1,100 degrees C. Apparatus performs fiber-pushout tests using radiant heating in vacuum. Vacuum maintained by turbopump prevents significant specimen oxidation during test. Successfully applied to metal and ceramic matrix composites being developed for jet engines. Applicable to many industrial applications, such as automotive components and energy-conversion devices. Previous Brief, "New Testing Tool for Composite Interfaces" (LEW-15297), describes apparatus designed to perform fiber-pushout testing at room temperature.

Eldridge, Jeffrey I.↗
NASA NTRSDate not supplied

Convertor Development for Dynamic Radioisotope Power Systems

Dynamic power conversion technologies are being developed for future space science and exploration missions by NASA’s Radioisotope Power Systems (RPS) Program, in collaboration with the U.S. Department of Energy (DOE). The Dynamic Radioisotope Power Systems (DRPS) Project is working to mature dynamic power convertors and controllers for infusion into a potential future flight generators.1,2 Maturation of power conversion technologies is being executed by the DRPS Project and the Thermal Energy Conversion Branch, located at NASA’s Glenn Research Center (GRC), and includes convertor technology development contracts and in-house controller development. The convertor technology development contracts consist of three contractors tasked to design, fabricate, and complete performance testing before the units are delivered to GRC for independent assessment. All contractors have completed convertor designs and are fabricating convertors to enable performance testing, while one has demonstrated initial performance of their design. The contractors also have provided generator conceptual designs, which utilize their respective convertor technologies being developed.

Dynamic↗
DOE OSTI2014

Cadmium exposure and neuropsychological development in school children in southwestern Spain

This study assessed the association between cadmium exposure and neuropsychological development in children from a region with high industrial and mining activities in southwestern Spain. We conducted a cross-sectional study with 261 children aged 6–9 years between January and March 2012. Cadmium exposure was measured in urine and hair of children, and neuropsychological development was assessed with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) and with three computerized tests from the Behavioral Assessment and Research System (BARS): Reaction Time Test (RTT), Continuous Performance Test (CPT) and Selective Attention Test (SAT). Multivariate linear regression models, adjusted for potential confounders, were used to estimate the association between neuropsychological development and cadmium exposure measured in urine and hair samples. Geometric means of urine and hair cadmium levels were 0.75 μg/g creatinine and 0.01 μg/g, respectively. We observed that doubling of levels of cadmium in urine was associated with a reduction of two points (95% CI: −3.8 to −0.4) in the Full-Scale intelligence quotient (IQ) in boys. By domains, association was statistically significant for Verbal Comprehension (β=−2.0; p=0.04) and close to the significance level for Perceptual Reasoning (β=−1.8; p=0.06). Among girls, only Verbal Comprehension showed suggestive associations with cadmium exposure (β=−1.7; p=0.06). Cadmium exposure is associated with cognitive delays in boys in our region. Our results provide additional evidence of the neurotoxic effect of low-level postnatal cadmium exposure among children, and support the hypothesis of differences between sexes in the neurotoxic effect of metals on children. - Highlights: • This study associates Cd exposure and neuropsychological development in children. • Cd exposure was associated with cognitive delay in boys, but not in girls. • Intellectual quotient of boys decreased two points for a doubling of urine Cd levels. • Verbal Comprehension and Perceptual Reasoning were the most affected domains in boys. • Results support the sex-related differences in the neurotoxicity of metals in children.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Department of Energy WindSentinel Loan Program Description

The U.S. Department of Energy (DOE) currently owns two AXYS WindSentinel buoys that collect a comprehensive set of meteorological and oceanographic data to support resource characterization for wind energy offshore. The two buoys were delivered to DOE’s Pacific Northwest National Laboratory (PNNL) in September, 2014. After acceptance testing and initial performance testing and evaluation at PNNL’s Marine Sciences Laboratory in Sequim, Washington, the buoys have been deployed off the U.S. East Coast. One buoy was deployed approximately 42 km east of Virginia Beach, Virginia from December, 2014 through June, 2016. The second buoy was deployed approximately 5 km off Atlantic City, New Jersey in November, 2015. Data from the buoys are available to the public. Interested parties can create an account and log in to http://offshoreweb.pnnl.gov. In response to a number of inquiries and unsolicited proposals, DOE’s Wind Energy Technologies Office is implementing a program, to be managed by PNNL, to lend the buoys to qualified parties for the purpose of acquiring wind resource characterization data in areas of interest for offshore wind energy development. This document describes the buoys, the scope of the loans, the process of how borrowers will be selected, and the schedule for implementation of this program, including completing current deployments.

17 WIND ENERGY↗
DOE OSTI2023

Cummins R-SOFC System Development

The overall purpose of this project was to reduce the Reversible-Solid Oxide Fuel Cell (R-SOFC) system cost by developing two technologies, an improved cell design and the incorporation of an ejector in the fuel recycle loop instead of a blower. A Simulink model of the baseline SOFC system was developed and calibrated with experimental test data. The R-SOFC system model was built by integrating GT Suite developed models of the steam generation components into the baseline Simulink SOFC system model. The ability to run the stack in SOEC operating mode was also added to the model. The system model was used to explore the ability of the R-SOFC system to meet operational constraints on Steam/Carbon ratio and H2 concentration on the fuel side electrode. A CFD ejector model was developed and used to explore a range of ejector design parameters, leading to the final ejector design that was prototyped for testing. A prototype steam ejector was first tested in a laboratory environment using room temperature air. The steam ejector was subsequently tested using the full hot recycle loop with all relevant heat exchangers and steam generation components. The test conditions utilized temperatures, pressures, and flow rates expected in an R-SOFC application. Throughout the experimental testing work, ejector performance test data was used to improve and then validate the CFD ejector model. A CFD cell model was developed and used to optimize thermal gradients, voltage, and cost of a new cell substrate design. A CFD comparison of co-flow and cross-flow cell designs informed the decision to use a co-flow design for the new cell substrate. Multiple rounds of CFD simulation were used to improve the cell design to minimize the variation in air and fuel distribution across cell channels and to minimize the variation in air and fuel distribution across different cells in the stack. A few prototypes of the new cell substrate design were produced and validated in a laboratory environment by thermally spraying and verifying that they met established manufacturing specifications. The cell manufacturing process was adjusted in order to bring these metrics within acceptable tolerances. Cummins’ internal calculations show that the new cell design reduces cost ~50% compared to the baseline cell, while the ejector + superheater/boiler concept reduces cost of the recycle loop by ~40%. The impact of these cost reductions on the cost of producing H2 will depend on the specific system where they are applied. Therefore, a Techno-Economic Analysis was completed using system cost as a variable, and showing how the NREL Current and Future system costs translate into H2 production cost.

Henrichsen, Lars↗
NASA NTRS1973

Raman scattering applied to gas mixing in the successive channel flow of two gases

The Raman scattering technique has been applied to investigate the effects of fluid undercutting in a simulation of the fluid-piston concept for wind-tunnel design. Measurements of the structure of the driver-driven gas interface and of the effect of undercutting on test duration were performed. Tests were conducted over a Froude number range of 0.0021 to 0.526 at driver-to-driven gas density ratios of 1.103 and 1.573. The effects of inlet design, test-channel inclination angle, and pretest pressurization were also examined. The results are compared with shadowgraph and pressure measurements to illustrate the characteristics of the Raman technique and to explain the discrepancy between the shadowgraph and pressure results.

Hillard, M. E., Jr.↗
NASA NTRS1976

Lightweight Long Life Heat Exchanger

A shuttle orbiter flight configuration aluminum heat exchanger was designed, fabricated, and tested. The heat exchanger utilized aluminum clad titanium composite parting sheets for protection against parting sheet pin hole corrosion. The heat exchanger, which is fully interchangeable with the shuttle condensing heat exchanger, includes slurpers (a means for removing condensed water from the downstream face of the heat exchanger), and both the core air passes and slurpers were hydrophilic coated to enhance wettability. The test program included performance tests which demonstrated the adequacy of the design and confirmed the predicted weight savings.

Moore, E. K.↗
NASA NTRS1983

X-wing noise data acquisition program

The X-wing circulation controlled rotor system model was tested for hover performance. During these performance tests, noise data from 12 microphones was recorded on magnetic tape for subsequent data reduction. The rotor system was operated at 4 tip speeds ranging from 529 to 650 ft./sec. (404 to 497 rpm), collective angles of attack fro 0 deg to 8.5 deg (maximum), and blade pressure ratios from 1.0 (no blowing) to a maximum of 2.1. The 12 microphones included 11 in the far field, and one in the transmission area. Following completion of the rotor and subsystem noise measurements, sound field calibration measurements were made of both the rotor 'bowl' and the loudspeaker system used in the 'bowl' calibration measurements. The location of 10 far field microphones was measured by a surveyor. Additionally, detailed tape logs were prepared for the six reels of tape used for the program.

Healy, G. J.↗
NASA NTRS1984

Radiative resistojet performance characterization tests

The test article, test approach, data analysis and results of a study undertaken to characterize performance of the augmentation section of the Rocket Research Company Augmented Catalytic Thruster as a gas resistojet using hydrogen, nitrogen and ammonia as propellants are described. This renewed interest in resistojets is a result of propulsion systems definition studies which indicate potential application to space station auxiliary propulsion.

Miyake, C. I.↗
NASA NTRS1984

Low-gravity solidification of cast iron and space technology applications

Two types of analyses relating to cast iron solidification were conducted. A theoretical analysis using a computer to predict the cooling versus time relationship throughout the test specimen was performed. Tests were also conducted in a ground-based laboratory to generate a cooling time curve for cast iron. In addition, cast iron was cooled through the solidification period on a KC-135 and an F-104 aircraft while these aircraft were going through a period of low gravity. Future subjects for low gravity tests are enumerated.

Graham, J. A.↗
NASA NTRS1987

DSN advanced receiver: Breadboard description and test results

A breadboard Advanced Receiver for use in the Deep Space Network was designed, built, and tested in the laboratory. Field testing was also performed during Voyager Uranus encounter at DSS-13. The development of the breadboard is intended to lead towards implementation of the new receiver throughout the network. The receiver is described on a functional level and then in terms of more specific hardware and software architecture. The results of performance tests in the laboratory and in the field are given. Finally, there is a discussion of suggested improvements for the next phase of development.

Brown, D. H.↗
NASA NTRS1988

Piezoelectric pushers for active vibration control of rotating machinery

The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers have been discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the stator. The use of piezoelectric pushers may provide similar degrees of effectiveness in light, compact packages. Tests are currently being conducted with piezoelectric pusher-based active vibration control. Results from tests performed on NASA test rigs as preliminary verification of the related theory are presented.

Palazzolo, Alan B.↗