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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 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Reduced-Order Modeling: Cooperative Research and Development at the NASA Langley Research Center

Cooperative research and development activities at the NASA Langley Research Center (LaRC) involving reduced-order modeling (ROM) techniques are presented. Emphasis is given to reduced-order methods and analyses based on Volterra series representations, although some recent results using Proper Orthogonal Deco in position (POD) are discussed as well. Results are reported for a variety of computational and experimental nonlinear systems to provide clear examples of the use of reduced-order models, particularly within the field of computational aeroelasticity. The need for and the relative performance (speed, accuracy, and robustness) of reduced-order modeling strategies is documented. The development of unsteady aerodynamic state-space models directly from computational fluid dynamics analyses is presented in addition to analytical and experimental identifications of Volterra kernels. Finally, future directions for this research activity are summarized.

Silva, Walter A.↗
NASA NTRS2000

Echo the Bat and the Pigeon Adventure

A multimedia, CD ROM to teach 2nd graders about remote sensing was created and developed into a web site. Distribution was expanded for Grades K-4 or 5-8. The idea was to have a story introduction, interactive story and a teacher's website. Interactive Multimedia Adventures in Grade School Education using Remote Sensing (I.M.A.G.E.R.S.) was created. The lessons are easy to use, readily available and aligned with national standards. This resource combines hands-on activities with an interactive web site

Butcher, Ginger↗
NASA NTRS2000

MSU Antenna Pattern Data

The Microwave Sounding Unit (MSU) antenna pattern data for nine MSU Flight Models (FMs) have been successfully rescued from 22-year old 7-track and 9-track magnetic tapes and cartridges. These antenna pattern data were unpacked into user-friendly ASCII format, and are potentially useful for making antenna pattern corrections to MSU antenna temperatures in retrieving the true brightness temperatures. We also properly interpreted the contents of the data and show how to convert the measured antenna signal amplitude in volts into relative antenna power in dB with proper normalization. It is found that the data are of high quality with a 60-dB drop in the co-polarized antenna patterns from the central peak value to its side-lobe regions at scan angles beyond 30 deg. The unpacked antenna pattern data produced in this study provide a useful database for data users to correct the antenna side-lobe contribution to MSU measurements. All of the data are available to the scientific community on a single CD-ROM.

Mo, Tsan↗
NASA NTRS2001

Imagine the Universe!

Welcome to Imagine the Universe! Contained on this CD-ROM you will find three astronomy and space science learning centers, individually captured from the World Wide Web in December of 2000. Each site contains its own learning adventure full of facts, fun, beautiful images, movies, and excitement. (1) Imagine The Universe: this site is dedicated to a discussion about our Universe... what we know about it, how it is evolving, and the kinds of objects and phenomena it contains. Emphasizing the X-ray and gamma-ray parts of the electromagnetic spectrum, it also discusses how scientists know what they know, what mysteries remain, and how the answers to remaining mysteries may one day be found. Lots of movies, quizzes, and a special section for educators. Geared for ages 14 and up. This site can be viewed on-line at http://imagine.gsfc.nasa.gov/. (2) StarChild- a learning center for young astronomers: the 1998 Webby Award Winner for Best Education Website, StarChild is aimed at ages 4-14. It contains easy-to-understand information about our Solar System, the Universe, and space exploration. There are also activities, songs, movies, and puzzles. This site can be viewed on-line at http://starchild.gsfc.nasa.gov/. (3) Astronomy Picture of the Day: APOD offers a new astronomical image and caption each calendar day. We have captured the year 2000 entries of this award-winning site and included them on the disk. The images and information provide a wonderful resource for all ages. This site can be viewed on-line at http://antwrp.gsfc.nasa.gov/apod/astropix.html.

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NASA NTRS2001

RTO Technical Publications: A Quarterly Listing

This is a listing of recent unclassified RTO technical publications processed by the NASA Center for AeroSpace Information. Reports may be downloaded for free from the RTO website at http:/www.rta.nato.int or they may be purchased from the NASA Center for AeroSpace Information, 7121 Standard Drive, Hanover, MID 21076-1320 USA, phone 301-621-0390, fax 301-621-0134. Prices and order forms are available from the NASA STI website at http://www.sti.nasa.gov. An automatic distribution of unclassified RTO technical publications in CD-ROM is also available within the U.S. through the NASA Standing Order Service from the NASA Center for AeroSpace Information.

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NASA NTRS1998

Space Transportation: Past, Present, and Future

This CD-ROM contains a multimedia presentation produced by NASA Marshall Space Flight Center. The production recounts the history of space transportation research from the early 20th Century to the present, including the current NASA/Orbital X-34 project. The CD includes motion pictures, animation and sound.

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NASA NTRS1995

World-Wide Web Tools for Locating Planetary Images

The explosive growth of the World-Wide Web (WWW) in the past year has made it feasible to provide interactive graphical tools to assist scientists in locating planetary images. The highest available resolution images of any site of interest can be quickly found on a map or plot, and, if online, displayed immediately on nearly any computer equipped with a color screen, an Internet connection, and any of the free WWW browsers. The same tools may also be of interest to educators, students, and the general public. Image finding tools have been implemented covering most of the solar system: Earth, Mars, and the moons and planets imaged by Voyager. The Mars image-finder, which plots the footprints of all the high-resolution Viking Orbiter images and can be used to display any that are available online, also contains a complete scrollable atlas and hypertext gazetteer to help locating areas. The Earth image-finder is linked to thousands of Shuttle images stored at NASA/JSC, and displays them as red dots on a globe. The Voyager image-finder plots images as dots, by longitude and apparent target size, linked to online images. The locator (URL) for the top-level page is http: //ic-www.arc.nasa.gov/ic/projects/bayes-group/Atlas/. Through the efforts of the Planetary Data System and other organizations, hundreds of thousands of planetary images are now available on CD-ROM, and many of these have been made available on the WWW. However, locating images of a desired site is still problematic, in practice. For example, many scientists studying Mars use digital image maps, which are one third the resolution of Viking Orbiter survey images. When they douse Viking Orbiter images, they often work with photographically printed hardcopies, which lack the flexibility of digital images: magnification, contrast stretching, and other basic image-processing techniques offered by off-the-shelf software. From the perspective of someone working on an experimental image processing technique for super-resolution, the discovery that potential users are often not using the highest resolution already available, nor using conventional image processing techniques, was surprising. This motivated the present work.

Kanefsky, Bob↗
NASA NTRS2001

Electron Heat Flux in Pressure Balance Structures at Ulysses

Pressure balance structures (PBSs) are a common feature in the high-latitude solar wind near solar minimum. Rom previous studies, PBSs are believed to be remnants of coronal plumes and be related to network activity such as magnetic reconnection in the photosphere. We investigated the magnetic structures of the PBSs, applying a minimum variance analysis to Ulysses/Magnetometer data. At 2001 AGU Spring meeting, we reported that PBSs have structures like current sheets or plasmoids, and suggested that they are associated with network activity at the base of polar plumes. In this paper, we have analyzed high-energy electron data at Ulysses/SWOOPS to see whether bi-directional electron flow exists and confirm the conclusions more precisely. As a result, although most events show a typical flux directed away from the Sun, we have obtained evidence that some PBSs show bi-directional electron flux and others show an isotropic distribution of electron pitch angles. The evidence shows that plasmoids are flowing away from the Sun, changing their flow direction dynamically in a way not caused by Alfven waves. From this, we have concluded that PBSs are generated due to network activity at the base of polar plumes and their magnetic structures axe current sheets or plasmoids.

Yamauchi, Yohei↗
NASA NTRS2002

Lunar and Planetary Science XXXIII

This CD-ROM publication contains the extended abstracts that were accepted for presentation at the 33rd Lunar and Planetary Science Conference held in Houston, TX, March 11-15, 2002. The papers are presented in PDF format and are indexed by author, keyword, meteorite, program and samples for quick reference.

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NASA NTRS2001

Tropical Rainfall Measuring Mission: Monitoring the Global Tropics for 3 Years and Beyond

The Tropical Rainfall Measuring Mission (TRMM) was launched in November 1997 as a joint U.S.-Japanese mission to advance understanding of the global energy and water cycle by providing distributions of rainfall and latent heating over the global tropics. As a part of NASA's Earth System Enterprise, TRMM seeks to understand the mechanisms through which changes in tropical rainfall influence global circulation. Additionally, a goal is to improve the ability to model these processes in order to predict global circulations and rainfall variability at monthly and longer time scales. Such understanding has implications for assessing climate processes related to El Nino/La Nina and Global Warming. TRMM has also provided unexpected and exciting new knowledge and applications in areas related to hurricane monitoring, lightning, pollution, hydrology, and other areas. This CD-ROM includes a self-contained PowerPoint presentation that provides an overview of TRMM and significant science results; a set of data movies or animation; and listings of current TRMM-related publications in the literature.

Shepherd, Marshall↗
NASA NTRS2002

Imagine the Universe! (6th Edition)

Contained on this CD-ROM you will find three astronomy and space science learning centers, individually captured from the World Wide Web in December of 2001. Each site contains its own learning adventure full of facts, fun, beautiful images, movies, and excitement!

Lochner, James↗
NASA NTRS2002

Toward An Understanding of Cluster Evolution: A Deep X-Ray Selected Cluster Catalog from ROSAT

In the past year, we have focussed on studying individual clusters found in this sample with Chandra, as well as using Chandra to measure the luminosity-temperature relation for a sample of distant clusters identified through the ROSAT study, and finally we are continuing our study of fossil groups. For the luminosity-temperature study, we compared a sample of nearby clusters with a sample of distant clusters and, for the first time, measured a significant change in the relation as a function of redshift (Vikhlinin et al. in final preparation for submission to Cape). We also used our ROSAT analysis to select and propose for Chandra observations of individual clusters. We are now analyzing the Chandra observations of the distant cluster A520, which appears to have undergone a recent merger. Finally, we have completed the analysis of the fossil groups identified in ROM observations. In the past few months, we have derived X-ray fluxes and luminosities as well as X-ray extents for an initial sample of 89 objects. Based on the X-ray extents and the lack of bright galaxies, we have identified 16 fossil groups. We are comparing their X-ray and optical properties with those of optically rich groups. A paper is being readied for submission (Jones, Forman, and Vikhlinin in preparation).

Jones, Christine↗
NASA NTRS1992

A Boon for the Architect Engineer

Langley Research Center's need for an improved construction specification system led to an automated system called SPECSINTACT. A catalog of specifications, the system enables designers to retrieve relevant sections from computer storage and modify them as needed. SPECSINTACT has also been adopted by government agencies. The system is an integral part of the Construction Criteria Base (CCB), a single disc containing design and construction information for 10 government agencies including the American Institute of Architects' MASTERSPEC. CCB employs CD- ROM technologies and is available from the National Institute of Building Sciences. Users report substantial savings in time and productivity.

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NASA NTRS2002

MODIS Snow and Ice Production

Daily, global snow cover maps, and sea ice cover and sea ice surface temperature (IST) maps are derived from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), are available at no cost through the National Snow and Ice Data Center (NSIDC). Included on this CD-ROM are samples of the MODIS snow and ice products. In addition, an animation, done by the Scientific Visualization studio at Goddard Space Flight Center, is also included.

Hall, Dorthoy K.↗
NASA NTRS2002

Experimental Test Results of Energy Efficient Transport (EET) High-Lift Airfoil in Langley Low-Turbulence Pressure Tunnel

This report describes the results of an experimental study conducted in the Langley Low-Turbulence Pressure Tunnel to determine the effects of Reynolds number and Mach number on the two-dimensional aerodynamic performance of the Langley Energy Efficient Transport (EET) High-Lift Airfoil. The high-lift airfoil was a supercritical-type airfoil with a thickness-to- chord ratio of 0.12 and was equipped with a leading-edge slat and a double-slotted trailing-edge flap. The leading-edge slat could be deflected -30 deg, -40 deg, -50 deg, and -60 deg, and the trailing-edge flaps could be deflected to 15 deg, 30 deg, 45 deg, and 60 deg. The gaps and overlaps for the slat and flaps were fixed at each deflection resulting in 16 different configurations. All 16 configurations were tested through a Reynolds number range of 2.5 to 18 million at a Mach number of 0.20. Selected configurations were also tested through a Mach number range of 0.10 to 0.35. The plotted and tabulated force, moment, and pressure data are available on the CD-ROM supplement L-18221.

Morgan, Harry L., Jr.↗
NASA NTRS2002

Experimental Investigation of Transition to Turbulence as Affected by Passing Wakes

Experimental results from a study of the effects of passing wakes upon laminar-to-turbulent transition in a low-pressure turbine passage are presented. The test section geometry is designed to simulate the effects of unsteady wakes resulting from rotor-stator interaction upon laminar-to-turbulent transition in turbine blade boundary layers and separated flow regions over suction surfaces. Single-wire, thermal anemometry techniques were used to measure time-resolved and phase-averaged, wall-normal profiles of velocity, turbulence intensity, and intermittency at multiple streamwise locations over the turbine airfoil suction surface. These data are compared to steady state, wake-free data collected in the same geometry to identify the effects of wakes upon laminar-to-turbulent transition. Results are presented for flows with a Reynolds number based on suction surface length and exit velocity of 50,000 and an approach flow turbulence intensity of 2.5 percent. From these data, the effects of passing wakes and associated increased turbulence levels and varying pressure gradients on transition and separation in the near-wall flow are presented. The results show that the wakes affect transition both by virtue of their difference in turbulence level from that of the free-stream but also by virtue of their velocity deficit relative to the freestream velocity, and the concomitant change in angle of attack and temporal pressure gradients. The results of this study seem to support the theory that bypass transition is a response of the near-wall viscous layer to pressure fluctuations imposed upon it from the free-stream flow. The data also show a significant lag between when the wake is present over the surface and when transition begins. The accompanying CD-ROM includes tabulated data, animations, higher resolution plots, and an electronic copy of this report.

Kaszeta, Richard W.↗
NASA NTRS2003

Preservation and Enhancement of the Spacewatch Data Archives

In March of 1998, the asteroid 1997 XF11 was announced to be potentially hazardous after being tracked over 90 days. A potential two year wait for confirming observations was shortened to under 24 hours because of the existence of archived photographic prediscovery images. Spacewatch was a pioneer in using CCD scanning and possesses a valuable digital archive of its scans. Unfortunately these data are aging on magnetic tape and will soon be lost. Since 1990, the Spacewatch project gathered some 1.5 Terabytes of scan data covering roughly 75,000 degrees of sky to a limiting magnitude of V = 21.5. The data have not yet been mined for all of their asteroids for scientific studies and orbit determination. Spacewatch's real-time motion detection program MODP was constrained by the computers of the era to use simplified image processing algorithms at a reduced efficiency. Jedicke and Herron estimated MODP's efficiency at finding asteroids to be approximately 60 percent to V=18 and improving somewhat thereafter. This lead to a substantial bias correction in their analyses. Larsen has developed a MODP replacement capable in excess of 90 percent efficiency in the same range and able to push a magnitude fainter in completeness. We propose a program of post-processing and re-archiving Spacewatch data. Our scans would be transferred from tape to CD-ROMs and converted to FITS images -- establishing a consistent data format and media for both past and future Spacewatch observations. Larsen's MODP replacement would mine these data for previously undetected motions, which would be made available to the Minor Planet Center and our ongoing asteroid population studies. A searchable observation record would be made generally available for prediscovery work. We estimate the net asteroid yield of this proposal is equivalent to three full years of Spacewatch operations.

Larsen, Jeffrey A.↗