SEARCH · Engineering Papers

Results for “SUSAN”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15

All sources NASA NTRS DOE OSTI

NASA NTRS1987

Shock structure measured in a transonic fan using laser anemometry

Shock structure measurements acquired in a low aspect ratio transonic fan rotor are presented and analyzed. The rotor aspect ratio is 1.56 and the design tip relative Mach number is 1.38. The rotor flowfield was surveyed at near maximum efficiency and near stall operating conditions. Intra-blade velocity measurements acquired with a laser fringe anemometer on blade-to-blade planes in the supersonic region from 10 to 60 percent span are presented. The three-dimensional shock surface determined from the velocity measurments is used to determine the shock surface normal Mach number in order to properly calculate the ideal shock jump conditions. The ideal jump conditions are calculated based upon the Mach numbers measured on a surface of revolution and based upon the normal Mach number to indicate the importance of accounting for shock three dimensionality in turbomachinery design. Comparison of the shock locations with those predicted by a 3-D Euler code showed very good agreement and indicated the usefulness of integrating computational and experimental work to enhance the understanding of the flow physics occurring in transonic turbomachinery passages.

Wood, Jerry R.↗

NASA NTRS1986

NASA Regional Planetary Image Facility image retrieval and processing system

The general design and analysis functions of the NASA Regional Planetary Image Facility (RPIF) image workstation prototype are described. The main functions of the MicroVAX II based workstation will be database searching, digital image retrieval, and image processing and display. The uses of the Transportable Applications Executive (TAE) in the system are described. File access and image processing programs use TAE tutor screens to receive parameters from the user and TAE subroutines are used to pass parameters to applications programs. Interface menus are also provided by TAE.

Slavney, Susan↗

NASA NTRS1987

CO2: Adsorption on palagonite and the Martian regolith

Possible scenarios for the evolution of the Martian climate are discussed. In the interest of determining an upper limit on the absorptive capacity of the Martian regolith, researchers examined the results of Fanale and Cannon (1971, 1974) for CO2 adsorption on nontronite and basalt. There appeared to be a strong proportionality between the capacity of the absorbent and its specific surface area. A model of the Martian climate is given that allows the researchers to make some estimates of exchangeable CO2 abundances.

Zent, Aaron P.↗

NASA NTRS1987

Formation of the layered deposits in the Valles Marineris, Mars

Thick sequences of layered deposits are found in the Valles Marineris, which exhibit fine, nearly horizontal layering, and are present as isolated plateaus of what were once more extensive deposits. It was argued that the morphology of the deposits is most consistent with origin in standing bodies of water. The conditions necessary for the existence of ice-covered Martian paleolakes are examined in detail and mechanisms for sediment deposition in them are considered. It was concluded that there are several geologically feasible mechanisms that could have led to the formation of thick deposits in ice-covered paleolakes in the Valles Marineris. Present data are insufficient to choose conclusively among the various possibilities. Several types of data from the Mars Observer mission will be useful in further characterizing the deposits and clarifying the process of their origin. The deposits should be considered important targets for a future Mars sample return mission.

Nedell, Susan S.↗

NASA NTRS1987

IRAS colors of VLA identified objects in the galaxy

Infrared Astronomy Satellite (IRAS) sources found within 4 degrees of l = 125 deg, b = 2 deg on the 3rd HCON 60 micron Sky Brightness Images were observed at the Very Large Array (VLA). Regions were to be identified where massive stars are forming by looking for small areas of radio continuum emissions. The IRAS sources could be divided into three groups by their IRAS 12 micron/25 micron and 60 micron/100 micron color. The group identified with star forming regions contained essentially all of the objects with extended radio emission. In all of these cases the extended radio emission showed a morphology consistent with the identification of these objects as HII regions. The conclusion drawn is that star formation regions can be distinguished from other objects by their infrared colors.

Fich, Michel↗

NASA NTRS1987

A correlation between the IRAS infrared cirrus at 60 or 100 microns and neutral atomic hydrogen in the outer galaxy

A linear correlation was found between the infrared cirrus at 100 or 60 microns and neutral atomic hydrogen near the galactic plane. Infrared Astronomy Satellite (IRAS) Sky Brightness images were compared to the 0.5 deg resolution Weaver-Williams HI survey in two regions of the outer Galaxy near l = 125 deg and l = 215 deg. The dust temperature inferred is nearly uniform and in reasonable agreement with theoretical predictions of thermal dust emission.

Terebey, Susan↗

NASA NTRS1986

Gaseous jets in Comet P/Halley

Properties of the gas jets in P/Halley reported to exist in images taken in the light of CN are described. The jets also exist in the light of other radicals, specifically C2. The jets do not exist in the continuum images although it appears that one of the jets seen may come from the same area on the nucleus that produces much of the dust. The jets are seen to persist, although with varying geometry, for 2 months or more, from the time of the spacecraft encounters in March to the beginning of May. The strength of the jets is well correlated with fluctuations in the overall production rate of radicals by the comet.

Ahearn, Michael F.↗

NASA NTRS1986

CN jets of Comet P/Halley: Rotational properties

An analysis of CCD images of CN jets of comet P/Halley observed during April 16 to 29 1986 is discussed. The analysis questions the 53 hr rotation period and favors a rotational period of 7.37 days, as suggested by Millis and Schleicher (1986). It is shown that a change in rotation period, at least from one apparition to the next, is also possible. A lower limit for the ejection velocity of dust grains (which emit CN) in the jet is established to be 0.5 km/sec with an uncertainty of 50%. The constraints on the direction of the rotation axis as inferred from the geometry of the jets are considered.

Samarasinha, Nalin H.↗

NASA NTRS1986

Ion morphology in the inner tail of Comet P/Halley

Comet Halley CCD images taken in the light of CO(+) and H2O(+) were analyzed. Most of the ionic emission originates in a diffuse component on which the ion ray structure appears to be superimposed. On average, the peak enhancement in the CO(+) rays is 20% over the adjacent minima, where the emission is due to the underlying component. The H2O(+):CO(+) ratio varies by as much as 30% from ray to ray.

Hoban, Susan↗

NASA NTRS1987

Advances in Planetary Geology

The surface of Mars displays a broad range of channel and valley features. There is as great a range in morphology as in scale. Some of the features of Martian geography are examined. Geomorphic mapping, crater counts on selected surfaces, and a detailed study of drainage basins are used to trace the geologic evolution of the Margaritifer Sinus Quandrangle. The layered deposits in the Valles Marineris are described in detail and the geologic processes that could have led to their formation are analyzed.

Grant, John A., III↗

NASA NTRS1987

Part 2: Sedimentary geology of the Valles, Marineris, Mars and Antarctic dry valley lakes

Detailed mapping of the layered deposits in the Valles Marineris, Mars from high-resolution Viking orbiter images revealed that they from plateaus of rhythmically layered material whose bases are in the lowest elevations of the canyon floors, and whose tops are within a few hundred meters in elevation of the surrounding plateaus. Four hypotheses for the origin of the layered deposits were considered: that they are eolian deposits; that they are remnants of the same material as the canyon walls; that they are explosive volcanic deposits; or that they were deposited in standing bodies of water. There are serious morphologic objections to each of the first three. The deposition of the layered deposits in standing bodies of water best explains their lateral continuity, horizontality, great thickness, rhythmic nature, and stratigraphic relationships with other units within the canyons. The Martian climatic history indicated that any ancient lakes were ice covered. Two methods for transporting sediment through a cover of ice on a martian lake appear to be feasible. Based on the presently available data, along with the theoretical calculations presented, it appears most likely that the layered deposits in the Valles Marineris were laid down in standing bodies of water.

Nedell, Susan S.↗

NASA NTRS1987

Observations of directional gamma prime coarsening during engine operation

Two alloys with negative mismatch parameters, NASAIR 100 and a modified NASAIR 100 called Alloy 3 were run as turbine blades in an experimental ground based Garret TFE731 engine for up to 200 hr. The directional coarsening of gamma prime (rafting) that developed during engine testing was analyzed and compared to previous research from laboratory tests. The blades were found to be rafted normal to the centrifugal stress axis over much of the span, but near the surfaces, the blades were found to be rafted parallel to the centrifugal stress axis for certain cycles. Representative photomicrographs of the blades and the effects of stress and temperature on raft formation are shown.

Draper, Susan L.↗

NASA NTRS1985

A workstation environment for software engineering

Information on a workstation environment for software engineering is given in outline form. Tools that help software engineers, elements of the present system, and future plans are noted.

Voigt, Susan J.↗

NASA NTRS1985

Engineering graphics and image processing at Langley Research Center

The objective of making raster graphics and image processing techniques readily available for the analysis and display of engineering and scientific data is stated. The approach is to develop and acquire tools and skills which are applied to support research activities in such disciplines as aeronautics and structures. A listing of grants and key personnel are given.

Voigt, Susan J.↗

NASA NTRS1985

Programming fault-tolerant distributed systems in Ada

Viewgraphs on the topic of programming fault-tolerant distributed systems in the Ada programming language are presented. Topics covered include project goals, Ada difficulties and solutions, testbed requirements, and virtual processors.

Voigt, Susan J.↗

NASA NTRS1986

Noise parameters and light sensitivity of low-noise high-electron-mobility transistors at 300 and 12.5 K

The four noise parameters of cryogenically cooled HEMTs have been investigated. Two different HEMT structures, with and without a spacer layer, were tested. The noise parameters of both structures were similar at room temperature, while they were dramatically different at cryogenic temperatures. The minimum noise temperatures measured at 8.4 GHz were 75 + or 5 K at room temperature and 8.5 + or - 1.5 K at the temperature of 12.5 K. The cryogenic performance is the best ever observed for field-effect transistors.

Pospieszalski, Marian W.↗

NASA NTRS1986

Cyanogen jets in comet Halley

Emission-band and continuum data were obtained of Comet Halley with a CCD camera system at the Perth Observatory during the post-perihelion phase. The image processing techniques which were applied and which revealed jets in the CN band are described. The jets had a spiral shape due to nucleus rotation at a rate which was not precisely determined. Estimates are made of the FWHM and half-width half-maximum spatial extent of the jets. Possible parent molecules of the CN jets are discussed.

Ahearn, Michael F.↗

NASA NTRS1987

Spectral reflectance of carbonate minerals in the visible and near infrared (0.35-2.55 microns) - Anhydrous carbonate minerals

Visible and near IR reflectance spectra for anhydrous carbonate minerals are presented, and the use of the spectra to determine the mineralogy and gaining information for the carbonate minerals is examined. Seven strong absorption bands at wavelengths greater than 1.6 microns are observed in all the spectra of anhydrous end-member carbonate minerals. The band position, intensity, and width for the carbonate bands are studied. The iron and maganese bands for the carbonate minerals are analyzed. The potential causes of spectral differences between carbonate minerals are investigated.

Gaffey, Susan J.↗