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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

High frequency data acquisition system for space shuttle main engine testing

The high frequency data acquisition system developed for the Space Shuttle Main Engine (SSME) single engine test facility at the National Space Technology Laboratories is discussed. The real time system will provide engineering data for a complete set of SSME instrumentation (approx. 100 measurements) within 4 hours following engine cutoff, a decrease of over 48 hours from the previous analog tape based system.

Lewallen, Pat↗
DOE OSTI2025

High-frequency Data Integration for Landscape Model Calibration of Carbon Fluxes Across Diverse Tidal Marshes

Terrestrial Aquatic Interfaces (TAIs), and tidal wetlands in particular, store large amounts of carbon yet are not well represented in Earth System Models (ESMs). Predictions of carbon cycling and greenhouse gas (GHG) emissions in tidal wetlands are highly uncertain. Eddy covariance (EC) towers provide ecosystem-scale GHG flux data at a temporal resolution (every 30min) that is helpful for parameterizing and improving mechanistic realism in ESMs. We propose to use a network of eddy covariance towers and standardized ancillary data streams, along with mesocosm experiments and statistical analyses, across diverse tidal wetlands of North America to develop and improve biogeochemical modeling at the TAI. Our overarching objective is to improve understanding and process-based modeling of gross primary productivity (GPP) and CH4 emission responses, both non-linear and asynchronous, to stressors including plant inundation, disturbance, salinity and nitrogen loading.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1991

High-frequency data observations from space shuttle main engine low pressure fuel turbopump discharge duct flex joint tripod failure investigation

Observations made by Marshall Space Flight Center (MSFC) engineers during their participation in the Space Shuttle Main Engine (SSME) low pressure fuel turbopump discharge duct flex joint tripod failure investigation are summarized. New signal processing techniques used by the Component Assessment Branch and the Induced Environments Branch during the failure investigation are described in detail. Moreover, nonlinear correlations between frequently encountered anomalous frequencies found in SSME dynamic data are discussed. A recommendation is made to continue low pressure fuel (LPF) duct testing through laboratory flow simulations and MSFC-managed technology test bed SSME testing.

Zoladz, T. F.↗
NASA NTRS1987

An expert system to analyze high frequency dependent data for the space shuttle main engine turbopumps

The prototype expert system ADDAMX identifies selected sinusoid frequencies from spectral data graphs as speed frequencies and harmonics from each turbopump, frequency feed through from one turbopump to another, frequencies generated by turbopump bearings, pseudo 3N for the phase 2 high pressure fuel turbopump, and electrical noise. ADDAMX does the analysis in an interactive or batch mode and the results can be displayed on the screen or hardcopy.

Garcia, Raul C., Jr.↗
DOE OSTI2025

High temporal frequency data from a four turbine, blade-resolved wind farm simulation with ExaWind

The data was generated with ExaWind (https://github.com/Exawind) which couples AMR-Wind (https://github.com/Exawind/amr-wind/), Nalu-Wind (https://github.com/Exawind/nalu-wind), TIOGA (https://github.com/Exawind/tioga), and OpenFAST (https://github.com/OpenFAST/openfast). This is a large-scale simulation of a blade-resolved wind farm using the ExaWind software stack. ExaWind couples together a background flow solver, AMR-Wind, and a near-body solver, Nalu-Wind, through an overset technique from the TIOGA application. Another application, OpenFAST, handles the structural dynamics of the turbine blades and towers, which informs the fluid-structure interaction of the wind turbines with the flow solvers. This particular simulation includes four blade-resolved wind turbines operating in a turbulent atmospheric boundary layer. The AMR-Wind solver uses 500 million cells and is being solved on 256 AMD GPUs of the Oakridge Leadership Computing Facility Frontier supercomputer. Each turbine is assigned its own Nalu-Wind solver with over 13 million elements per turbine and solved using 448 CPU cores, for a total of 1792 CPU cores. For each node, 56 cores contain Nalu-Wind, while 8 cores correspond to AMR-Wind operations on the GPUs. Consequently, ExaWind is entirely utilizing the CPUs and the GPUs of the nodes concurrently. The data used in the visualization is full flow field data output from the simulation. It is lossy-compressed to a specific accuracy using ZFP and written to disk every 16 time-steps to enable real-time flow visualization. The flow fields are sampled at a high temporal frequency to enable real-time, 24fps visualization. The flow fields are sampled every 12 simulation time steps (every 0.04132s).

17 WIND ENERGY↗
DOE OSTI2025

WREF Halo Streamline scanning lidar / Derived data / High-frequency wind profiles

This dataset contains wind profiles retrieved from 6-beam Velocity Azimuth Display (VAD) scans done by the UC Davis scanning Lidar. The wind components (expressed as zonal, meridional and vertical) are retrieved through the algorithm of Paschke et al. (2015). The quality control of the radial wind speed is performed following the algorithm of Goring & Nikora (2002).

17 WIND ENERGY↗
NASA NTRS1990

Portable High-Frequency Data-Acquisition System

Compact unit made of readily available solid-state components. Proposed system for acquisition of rapidly changing data self-contained and portable. Conceived for monitoring such aerodynamic effects as flutter, vibration, shock, sound, and pressure. Offers precise and fast acquisition of data and large data-storage capacity: has maximum sampling rate of 125 kHz, access time of 15 ns, and 1-million-bit memory. Measures time with "smart" (microprocessor-controlled) watch that maintains calendar time for more than 10 years without external power. Provides standby power from "smart" battery furnishing up to 1 ampere-hour of charge if power from main batteries lost.

Mustain, Roy W.↗
NASA NTRS1990

Representation of high frequency Space Shuttle data by ARMA algorithms and random response spectra

High frequency Space Shuttle lift-off data are treated by autoregressive (AR) and autoregressive-moving-average (ARMA) digital algorithms. These algorithms provide useful information on the spectral densities of the data. Further, they yield spectral models which lend themselves to incorporation to the concept of the random response spectrum. This concept yields a reasonably smooth power spectrum for the design of structural and mechanical systems when the available data bank is limited. Due to the non-stationarity of the lift-off event, the pertinent data are split into three slices. Each of the slices is associated with a rather distinguishable phase of the lift-off event, where stationarity can be expected. The presented results are rather preliminary in nature; it is aimed to call attention to the availability of the discussed digital algorithms and to the need to augment the Space Shuttle data bank as more flights are completed.

Spanos, P. D.↗
DOE OSTI2025

A1 LLNL Profiling Lidar #773

This dataset contains vertical profiling lidar data from AWAKEN site A1. This is the ZephIR300 #773 lidar system. The .csv files are monthly data files with 10-min average data. The .zip files are daily high frequency data and zipped by month.

17 WIND ENERGY↗
NASA NTRS1981

Super-Schottky mixer performance at 92 GHz

As part of a program to investigate the behavior of superconducting Schottky mixers at high frequencies, the mixing and video performance of several super-Schottky diodes (a 3-micron active diameter, and a doping concentration of 2 x 10 to the 19th per cu cm) have been tested at 92 GHz. At 92 GHz, video responsivities were typically 80 A/W (corrected for RF mismatch). Conversion loss (corrected for both RF and IF mismatches) was typically not less than 18 dB. As expected, diode temperature was low (less than 5 K). Video responsivity and conversion loss were also measured at an RF frequency of 3.95 GHz. These data were used with the measured volt-ampere characteristics of the diodes to compare theoretical predictions of diode performance at 92 GHz, in both the video and mixing modes, with the high-frequency data

Dickman, R. L.↗