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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

RELAP5-3D Pre-test Prediction for High Temperature Test Facility Test PG-26

The RELAP5-3D computer code has been used to perform a pre-test prediction for Test PG-26 in the High Temperature Test Facility at Oregon State University. Test PG-26 will simulate a pressurized conduction cooldown transient following a trip of the primary coolant system gas circulator. The facility is initialized with a steady-state power of 700 kW and prototypic core inlet and outlet helium coolant temperatures of 259 and 687°C, respectively. Sensitivity calculations addressed the flow coastdown time, the reactor cavity cooling system flow rate and temperature, and decay power.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1972

Test report: Shock test of the electron/proton spectrometer structural test unit

A shock test of the electron-proton spectrometer structural test unit was conducted. The purpose of the shock test was to verify the structural integrity of the electron-spectrometer design and to obtain data on the shock response of the electronics and electronic housing. The test equipment is described and typical shock response data are provided.

Vincent, D. L.↗
DOE OSTI2019

Hyperspectral vegetation identification at a legacy underground nuclear explosion test site

The detection, location, and identification of suspected underground nuclear explosions (UNEs) are global security priorities that rely on integrated analysis of multiple data modalities for uncertainty reduction in event analysis. Vegetation disturbances may provide complementary signatures that can confirm or build on the observables produced by prompt sensing techniques such as seismic or radionuclide monitoring networks. For instance, the emergence of non-native species in an area may be indicative of anthropogenic activity or changes in vegetation health may reflect changes in the site conditions resulting from an underground explosion. Previously, we collected high spatial resolution (10 cm) hyperspectral data from an unmanned aerial system at a legacy underground nuclear explosion test site and its surrounds. These data consist of visible and near-infrared wavebands over 4.3 km 2 of high desert terrain along with high spatial resolution (2.5 cm) RGB context imagery. In this work, we employ various spectral detection and classification algorithms to identify and map vegetation species in an area of interest containing the legacy test site. Here, we employed a frequentist framework for fusing multiple spectral detections across various reference spectra captured at different times and sampled from multiple locations. The spatial distribution of vegetation species is compared to the location of the underground nuclear explosion. We discover a difference in species abundance within a 130 m radius of the center of the test site.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1972

Fabrication and test of a space power boiler feed electromagnetic pump. Part 2: Test facility and performance test

A three-phase helical induction electromagnetic pump, designed for the boiler-feed pump of a potassium Rankine-cycle space power system, was built and tested. The pump was tested over a range of potassium temperatures from 900 to 1400 F, flow rates from 0.75 to 4.85 lb/sec, developed pressures up to 340 psi, net positive suction heads (NPSH) from 1 to 22 psi, and NaK coolant temperatures from 800 to 950 F. The maximum efficiency at the pump design point of 3.25 lb/sec flow rate, 240 psi developed pressure, 1000 F potassium inlet temperature, and 800 F NaK coolant temperature was 16.3 percent. The tests also showed successful operation of the pump at an NPSH as low as 1.5 psi without cavitating.

Powell, A. H.↗
NASA NTRS1972

Design, analysis, and tests of a structural prototype Viking aeroshell. I - Aeroshell design and analysis. II - Test procedure and test results.

Two near optimum full-scale Viking aeroshell prototypes (140 deg ring-stiffened conical shells), differing only in base ring size, were designed and tested under uniform pressure to buckling failure. Part I describes the computerized design procedure which iterates between a design program based on approximate equations to determine skin and ring gages and ring spacings, and a sophisticated system of shell of revolution programs for more accurate analysis as a basis for redesign. Part II discusses fabrication techniques, test procedures, and test results. Both buckling and prebuckling data are compared with the theoretical predictions of Part I. Appropriate buckling knockdown factors for this type of construction are identified. Measured strains in skin and rings agreed well with theoretical predictions and the buckling pressure was in close agreement with the design ultimate pressure.

Heard, W. L., Jr.↗
NASA NTRS1972

Test report: Vibration testing of the electron/proton spectrometer structural test unit

The structural test unit of the electron-proton spectrometer was tested to a random vibration spectra and to a sinusoidal resonant search to comply with the requirements of a verification plan for the spectrometer. The test item consisted of mass simulated electronic and printed circuit boards mounted in a flight type electronic housing. The arrangement, center of gravity, and weight were as proposed for flight units.

Vincent, D. L.↗
NASA NTRS1975

Viking 1975 orbiter development test model/Lander dynamic test model, dynamic environmental testing

A series of dynamic environmental tests on the Viking 1975 Orbiter/Lander model provided information regarding damping and linearity. The quality of mode isolation was made with orthogonality checks. A pretest criterion established for orthogonality provided good correlation with test results. Part of the post-test analysis was dedicated to a review of instrumentation selection for control and/or response limiting. Limited load values were also examined.

Milder, G.↗
NASA NTRS1986

Implementation and flight tests for the Digital Integrated Automatic Landing System (DIALS). Part 1: Flight software equations, flight test description and selected flight test data

Five flight tests of the Digital Automated Landing System (DIALS) were conducted on the Advanced Transport Operating Systems (ATOPS) Transportation Research Vehicle (TSRV) -- a modified Boeing 737 aircraft for advanced controls and displays research. These flight tests were conducted at NASA's Wallops Flight Center using the microwave landing system (MLS) installation on runway 22. This report describes the flight software equations of the DIALS which was designed using modern control theory direct-digital design methods and employed a constant gain Kalman filter. Selected flight test performance data is presented for localizer (runway centerline) capture and track at various intercept angles, for glideslope capture and track of 3, 4.5, and 5 degree glideslopes, for the decrab maneuver, and for the flare maneuver. Data is also presented to illustrate the system performance in the presence of cross, gust, and shear winds. The mean and standard deviation of the peak position errors for localizer capture were, respectively, 24 feet and 26 feet. For mild wind conditions, glideslope and localizer tracking position errors did not exceed, respectively, 5 and 20 feet. For gusty wind conditions (8 to 10 knots), these errors were, respectively, 10 and 30 feet. Ten hands off automatic lands were performed. The standard deviation of the touchdown position and velocity errors from the mean values were, respectively, 244 feet and 0.7 feet/sec.

Hueschen, R. M.↗
NASA NTRS1947

Wind-Tunnel Tests of the 1/25-Scale Powered Model of the Martin JRM-1 Airplane. IV - Tests with Ground Board and with Modified Wing and Hull - TED No. NACA 232: Tests with Ground Board and with Modified Wing and Hull, TED No. NACA 232 - Part 4

Wind-tunnel tests were made of a 1/25 scale model of the Martin JRM-1 airplane to determine: (1) The longitudinal stability and control characteristics of the JRM-1 model near the water and lateral and directional stability characteristics with power while moving on the surface of the water, the latter being useful for the design of tip floats; (2) The stability and stalling characteristics of the wing with a modified airfoil contour; (3) Stability characteristics of a hull of larger design gross weight; The test results indicated that the elevator was powerful enough to trim the original model in a landing configuration at any lift coefficient within the specified range of centers of gravity. The ground-board tests for evaluating the aerodynamic forces and moments on an airplane in a simulated cross wind indicate a high dihedral effect in the presence of the ground board and, consequently, during low-speed taxying and take-off, large overturning moments would result which would have to be overcome by the tip floats.

Lockwood, Vernard E.↗
DOE OSTI2016

Testing and validation of multi‐lidar scanning strategies for wind energy applications

Abstract Several factors cause lidars to measure different values of turbulence than an anemometer on a tower, including volume averaging, instrument noise and the use of a scanning circle to estimate the wind field. One way to avoid the use of a scanning circle is to deploy multiple scanning lidars and point them toward the same volume in space to collect velocity measurements and extract high‐resolution turbulence information. This paper explores the use of two multi‐lidar scanning strategies, the tri‐Doppler technique and the virtual tower technique, for measuring 3‐D turbulence. In summer 2013, a vertically profiling Leosphere WindCube lidar and three Halo Photonics Streamline lidars were operated at the Southern Great Plains Atmospheric Radiation Measurement site to test these multi‐lidar scanning strategies. During the first half of the field campaign, all three scanning lidars were pointed at approximately the same point in space and a tri‐Doppler analysis was completed to calculate the three‐dimensional wind vector every second. Next, all three scanning lidars were used to build a ‘virtual tower’ above the WindCube lidar. Results indicate that the tri‐Doppler technique measures higher values of horizontal turbulence than the WindCube lidar under stable atmospheric conditions, reduces variance contamination under unstable conditions and can measure high‐resolution profiles of mean wind speed and direction. The virtual tower technique provides adequate turbulence information under stable conditions but cannot capture the full temporal variability of turbulence experienced under unstable conditions because of the time needed to readjust the scans. Copyright © 2016 John Wiley & Sons, Ltd.

Newman, Jennifer F.↗
DOE OSTI2024

Wind Farm Wakes and Farm-to-Farm Interactions: Lidar and Wind Tunnel Tests

Recent experimental and numerical evidence has shown that the cumulative wake generated from the overlapping of multiple wakes within a wind farm could reduce power performance and enhance fatigue loads of wind turbines installed in neighboring downstream wind farms and may also extend up to distances one order of magnitude larger than those typically considered for intra-farm wake interactions. Similar to individual wind turbine wakes, wind farm wakes have a velocity deficit and added turbulence intensity, both affected by the turbine rotor thrust forces and the incoming turbulence intensity. Therefore, the evolution of wind farm wakes will vary for different operational and atmospheric conditions. In this paper, lidar measurements collected during the American WAKE experimeNt (AWAKEN) and wind tunnel tests of wind farms reproduced by porous disks are leveraged to investigate wind farm wakes.

17 WIND ENERGY↗
DOE OSTI2018

HPHT 17TR8 Test Articles: Post-Test Characterization Following Pressure Burst Testing (Final)

The objective of this study was to investigate whether F22 forging material ’s properties change near the failure location, in the event that two full-scale test pieces are intentionally taken to burst failure. 1 The two full-scale test pieces were created per high-pressure high-temperature guidelines in API 17TR8 and ASME Section VIII references in those guidelines.

36 MATERIALS SCIENCE↗