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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Oxygen and sulfur interactions with a clean iron surface and the effect of rubbing contact on these interactions

The interaction of sulfur and oxygen with an iron surface was studied with Auger spectroscopy analysis both statically and during sliding-friction experiments in a vacuum environment. Oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide were adsorbed to an iron surface. Results indicate that sulfide films formed on clean iron surfaces are completely displaced by oxygen. Hydrocarbons containing sulfur, such as methyl mercaptan, adsorb dissociatively. Less sulfur is adsorbed during sliding with hydrogen sulfide and methyl mercaptan than in the absence of sliding. With both oxygen and sulfur dioxide, sliding did not affect the amount of material adsorbed to iron.

Buckley, D. H.↗
NASA NTRS1974

Lunar interactions: Abstracts of papers presented at the Conference on Interactions of the Interplanetary Plasma with the Modern and Ancient Moon

Reviewed are the active mechanisms relating the moon to its environment and the linkage between these mechanisms and their records in the lunar sample and geophysical data. Topics: (1) large scale plasma interactions with the moon and non-magnetic planets; (2) ancient and present day lunar surface magnetic and electric fields; (3) dynamics and evolution of the lunar atmosphere; (4) evolution of the solar plasma; (5) lunar record of solar radiations; (6) non-meteoritic and meteoritic disturbance and transport of lunar surface materials; and (7) future lunar exploration.

Criswell, D. R.↗
NASA NTRS1973

Oxygen and sulfur interactions with a clean iron surface and the effect of rubbing contact on these interactions

An investigation was conducted to determine the nature of the chemical interactions of oxygen and sulfur with iron when surfaces are stationary and also during sliding in a vacuum environment. Various gases that contained sulfur, oxygen, or both were adsorbed to iron at 23 C. The gases included oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide. Friction experiments were conducted with a hemispherical rider sliding on a rotating disk. An Auger cylindrical mirror analyzer was used to monitor the iron surface chemistry. The results of this study indicate that oxygen will completely displace sulfide films from iron surfaces. Organic thiols containing sulfur, such as methyl mercaptan, adsorb to an iron surface dissociatively. Only sulfur is detected on the iron surface. Sliding inhibits the formation of sulfide films on iron with the adsorption of hydrogen sulfide and methyl mercaptan. With oxygen and sulfur dioxide, the sliding process does not affect adsorption behavior.

Buckley, D. H.↗
NASA NTRS1982

An investigation of adhesive/adherend and fiber/matrix interactions. Part A: Surface characterization of titanium dioxide, titantium and titanium 6% Al to 4% V powders: Interaction with water, hydrogen chloride and polymers

The titanium dioxide surface is discussed. Polymer adhesive are also discussed. Titanium powders are considered. Characterization techniques are also considered. Interactions with polymers, water vapor, and HCl are reported. Adsorbents are characterized.

Siriwardane, R. V.↗
NASA NTRS1987

A magnetohydrodynamic model of the interaction of the solar wind with the Jovian magnetosphere and a magnetohydrodynamic simulation of the interaction of the solar wind with the out flowing plasma from a comet

A three-dimensional code for a rapidly rotating magnetosphere in which the MHD equations and the Maxwell equations were solved by using the two step Lax Endroff scheme, was developed. Preliminary results were presented at the Fall AGU meeting in San Francisco. The basic simulation model to study the solar wind interactions was adapted to other bodies in addition to Jupiter. Because of the recent comet flybys, a comet was chosen as the first model. The aim was to model the formation of the contact surface and the plasma tail. Later, work was begun on a three-dimensional model which would include the effects of mass loading. This model was designed to study the weak cometary bow shocks observed by the probes to comets Halley and Giacobini-Zinner. The model was successful in reproducing the position and shape of the bow shock which was determined by using observations from the Suisei spacecraft.

Walker, R. J.↗
NASA NTRS1989

Laboratory studies of wave-current interaction - Kinematics of the strong interaction

Controlled laboratory experiments have been conducted to study the kinematics of wave-current interactions. The results confirm the conservation of waves under the steady state condition. The data also show that the kinematic effect of the current on waves can be treated as a simple Doppler shift. After the Doppler correction, the kinematics of the waves (either breaking or nonbreaking) follow the linear theory very well.

Lai, Ronald J.↗
NASA NTRS2012

Particle-Surface Interaction Model and Method of Determining Particle-Surface Interactions

A method and model of predicting particle-surface interactions with a surface, such as the surface of a spacecraft. The method includes the steps of: determining a trajectory path of a plurality of moving particles; predicting whether any of the moving particles will intersect a surface; predicting whether any of the particles will be captured by the surface and/or; predicting a reflected trajectory and velocity of particles reflected from the surface.

Hughes, David W.↗
NASA NTRS2007

Creating Interactive Graphical Overlays in the Advanced Weather Interactive Processing System (AWIPS) Using Shapefiles and DGM Files

Graphical overlays can be created in real-time in the Advanced Weather Interactive Processing System (AWIPS) using shapefiles or DARE Graphics Metafile (DGM) files. This presentation describes how to create graphical overlays on-the-fly for AWIPS, by using two examples of AWIPS applications that were created by the Applied Meteorology Unit (AMU). The first example is the Anvil Threat Corridor Forecast Tool, which produces a shapefile that depicts a graphical threat corridor of the forecast movement of thunderstorm anvil clouds, based on the observed or forecast upper-level winds. This tool is used by the Spaceflight Meteorology Group (SMG) and 45th Weather Squadron (45 WS) to analyze the threat of natural or space vehicle-triggered lightning over a location. The second example is a launch and landing trajectory tool that produces a DGM file that plots the ground track of space vehicles during launch or landing. The trajectory tool can be used by SMG and the 45 WS forecasters to analyze weather radar imagery along a launch or landing trajectory. Advantages of both file types will be listed.

Barrett, Joe H., III↗
NASA NTRS2017

Particle Radiation Sources, Propagation and Interactions in Deep Space, at Earth, the Moon, Mars, and Beyond: Examples of Radiation Interactions and Effects

Particle radiation has significant effects for astronauts, satellites and planetary bodies throughout the Solar System. Acute space radiation hazards pose risks to human and robotic exploration. This radiation also naturally weathers the exposed surface regolith of the Moon, the two moons of Mars, and other airless bodies, and contributes to chemical evolution of planetary atmospheres at Earth, Mars, Venus, Titan, and Pluto. We provide a select review of recent areas of research covering the origin of SEPs from coronal mass ejections low in the corona, propagation of events through the solar system during the anomalously weak solar cycle 24 and important examples of radiation interactions for Earth, other planets and airless bodies such as the Moon.

Schwadron, Nathan A.↗
NASA NTRS1973

Auger analysis of oxygen and sulfur interactions with various metals and the effect of sliding on these interactions

Various gases were adsorbed to copper, aluminum, and chromium surfaces. The gases included oxygen, hydrogen sulfide, methyl mercaptan, and sulfur dioxide. Chemisorption was conducted on static surfaces and during dynamic friction experiments. An Auger cyclindrical mirror analyzer was used to monitor surface films. The sulfur containing gases adsorbed readily to all surfaces. Exposures of as little as 0.000001 (torr)(sec) (1 langmuir) were sufficient to reduce friction. Sliding contact did not affect chemisorption of copper or aluminum but did affect chemisorption to chromium surfaces. Oxygen removed sulfur films from all surfaces at room temperature (23 C). Gaseous exposures were from 0.000001 to 0.01 (torr)(sec) (1 to 10,000 langmuirs).

Buckley, D. H.↗
NASA NTRS1992

Studies of shock/shock interaction on smooth and transpiration-cooled hemispherical nosetips in hypersonic flow

A program of experimental research and analysis was conducted to examine the heat transfer and pressure distributions in regions of shock/shock interaction over smooth and transpiration-cooled hemispherical noseshapes. The objective of this investigation was to determine whether the large heat transfer generated in regions of shock/shock interaction can be reduced by transpiration cooling. The experimental program was conducted at Mach numbers of 12 to 16 in the Calspan 48-Inch Shock Tunnel. Type 3 and type 4 interaction regions were generated for a range of freestream unit Reynolds numbers to provide shear layer Reynolds numbers from 10 exp 4 to 10 exp 6 to enable laminar and turbulent interaction regions to be studied. Shock/shock interactions were investigated on a smooth hemispherical nosetip and a similar transpiration-cooled nosetip, with the latter configuration being examined for a range of surface blowing rates up to one-third of the freestream mass flux. While the heat transfer measurements on the smooth hemisphere without shock/shock interaction were in good agreement with Fay-Riddell predictions, those on the transpiration-cooled nosetip indicated that its intrinsic roughness caused heating-enhancement factors of over 1.5. In the shock/shock interaction studies on the smooth nosetip, detailed heat transfer and pressure measurements were obtained to map the variation of the distributions with shock-impingement position for a range of type 3 and type 4 interactions. Such sets of measurements were obtained for a range of unit Reynolds numbers and Mach numbers to obtain both laminar and turbulent interactions. The measurements indicated that shear layer transition has a significant influence on the heating rates for the type 4 interaction as well as the anticipated large effects on type 3 interaction heating. In the absence of blowing, the peak heating in the type 3 and type 4 interaction regions, over the transpiration-cooled model, did not appear to be influenced by the model's rough surface characteristics. The studies of the effects of the transpiration cooling on type 3 and type 4 shock/shock interaction regions demonstrated that large surface blowing rates had significant effect on the structure of the flowfield, enlarging the shock layer and moving the region of peak-heating interaction around the body.

Holden, Michael S.↗
NASA NTRSDate not supplied

Implicit Large-Eddy Simulation of Axisymmetric and Asymmetric Turbulent Shock Wave Boundary Layer Interaction at Mach 2.5

High-speed inlet flows feature turbulent shock wave boundary layer interactions at supersonic Mach numbers. A canonical Mach 2.5 shock wave boundary layer interaction experiment at the NASA Glenn Research Center was designed for axisymmetric and asymmetric interactions depending on the placement of the shock generator. Four different wall-resolved implicit large-eddy simulations of the experiment were carried out at one-tenth of the Reynolds number of the experiment: (1) Two axisymmetric interactions with shock generator radii of 9.2% and 14.7% of the test section diameter and (2) two asymmetric interactions with 14.7% shock generator radius and shock generator centerline offsets of one-third and one-fourth of the test section radius. For the two axisymmetric interactions, various sub-domains upstream of the interaction, within the interaction, and downstream of the interaction were analyzed with the proper orthogonal decomposition. For all three regions, the dominant modes are streamwise coherent structures with Strouhal numbers based on separation length of 0.15 and below. Fourier spectra of the wall-pressure coefficient for the interaction region have peaks at Strouhal numbers based on separation length of 0.15 and 0.04. For the two asymmetric interactions, the streamwise extent of the separation varies considerably in the azimuthal direction. For both shock generator offsets, the interaction is strongest for the azimuthal location that is closest to the shock generator. Compared to the axisymmetric interaction, the streamwise extent of the separated flow region is noticeably reduced and a substantial crossflow is observed. Fourier analyses of the unsteady flow indicate low-frequency content f or the upstream part of the interaction which is more two-dimensional. Away from the upstream region, with increasing sweep angle and crossflow, the low-frequency content is diminished.

Computational Fluid Dynamics↗