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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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Liquid sloshing in liquid propellant containing orbiting vehicle stabilized by active control system, examining expression for ring baffle slosh damping under reduced gravity
Plasma sheet proton ring current, trapping boundary and plasmapause interrelations near magnetic equator and local midnight by satellite- borne analyzer array
Saturn, Titan and ring IR photometric observations, examining brightness temperature albedos, optical thickness and individual particles
OGO-2 rubidium vapor magnetometer measurements comparison with surface magnetic observatory data during geomagnetic storms, considering asymmetric ring current
Tuff rings from Fort Rock-Christmas Lake Valley basin, investigating morphologic and volcanic features for surface water role in genesis
A FORTRAN 4 digital computer program is presented for the initial postbuckling and imperfection sensitivity analysis of bifurcation buckling modes for ring-stiffened orthotropic multilayered shells of revolution. The boundary value problem for the second-order contribution to the buckled state was solved by the forward integration technique using the Runge-Kutta method. The effects of nonlinear prebuckling states and live pressure loadings are included.
A classification of maars, tuff-rings, tuff-cones, and diatremes is given along with a summary of their lithologic and structural characteristics at the surface and at depth, and their probable manner of formation. Particular emphasis is placed on the roles of fluidization and groundwater.
In an effort to summarize the constrasting development of the stormtime ring currents during the December 16-18, 1971 magnetic storms, maps were drawn indicating the proton energy density spatial/temporal distributions. The maps contain distributions for the 5 to 138 keV protons for each of seven orbits. The first storm was not characteristic of a single substorm nor a fully developed magnetic storm, but it was comprised of a sudden commencement, a positive phase, and multiple substorms producing a small depression in the magnetic field. The second storm was classical in development with a short two hour growth phase. Energy density distribution constrasts for the two storms show the second storm displayed three dominant features over the first storm. They were: (1) the intensities were 2 1/2 times larger, (2) the depths of penetration were 1/2 to 1 Reynolds number lower, and (3) the distribution became symmetric.
Carbon-graphite seal ring bodies for operation at air temperatures to 1300 F(704 C) were manufactured from three select formulations. Mechanical and thermal properties, porosities, and oxidation rates were measured. The results have shown that: (1) Major property improvements anticipated from the screening studies were not realized because of processing problems associated with the scale-up in material size and probable deterioration of a phenolic resin binder; (2) the mechanical properties of a phenolic resin-bonded, carbon-graphite material can be improved by applying high pressure during carbonization; and (3) the textile form of graphite fiber used as the minor filler component in a carbon-graphite material can beneficially affect mechanical properties.
An experimental study was undertaken of damping produced by single flexible-ring baffles in a 396-cm diameter tank of liquid nitrogen. Two 24.8-cm wide baffles were tested. One baffle was 0.00635 cm thick type 301 stainless steel and the other 0.0254 cm thick Teflon FEP. Each baffle produced damping of liquid oscillations equal to or greater than that expected from rigid baffles of the same size. The equations used to determine the baffle thickness required were found to be adequate baffle design equations.
Review of data obtained on turbulent burst geometry and growth characteristics for cone boundary-layer transition in a helium wind tunnel at a boundary-layer edge Mach number (Me) of 7.6. Detailed data concerning turbulent spot geometry and downstream propagation velocities were obtained using a spark schlieren system with sequential spark capability. In one particular test evidence of a symmetrical turbulent burst ring was obtained; all other bursts developed in a singular random manner. Profiles of the apparent outer edges of the bursts were obtained, and the velocities of the leading and trailing edges of the bursts relative to the local velocity were determined. The velocities of the leading and trailing edges were found to be fairly consistent for each observation, with the leading edge of the burst traveling at about local edge velocity, while the trailing edge moved supersonically relative to local speed.
The problem of a spinning satellite with a partially filled viscous ring damper is investigated. It is shown that there are two distinct modes of motion, the nutation-synchronous mode and spin-synchronous mode. From an approximate solution of the equations of motion a time constant is obtained for each mode. From a consideration of the fluid dynamics several methods are developed for determining the damping constant.
Demonstration that the output from a ring core sensor is directly proportional to the first time derivative of the product of dynamic permeability and magnetic intensity perturbation within the core caused by an external, uniform magnetic field. (Dynamic permeability is defined to be the slope of the hysteresis loop at a given point in time). Assuming that ellipsoidal shells can approximate the core, the demagnetization factor can be 'estimated' in the first order to be proportional to the first power of the quantity tape thickness (or number of wraps) divided by the core diameter. The constant of proportionality is determined from laboratory data. When an additional scale adjustment is applied to the resulting sensor output formula, the computed output tracks laboratory data for a range of sensor geometries.
In the application of Monte Carlo computer techniques to the study of problems in the free molecular flow regime, the analogy between radiation heat transfer with diffuse emissions and the free molecular flow field makes it possible to use the radiation configuration factors as a test on the operation of the Monte Carlo program. A source plane which was an annular ring of arbitrary radius around a sphere with the center of the disk coincident with the center of the sphere was examined. Since various indicators seemed to verify the correct operation of the program, the program was used to calculate the radiation configuration factors. The study adds a new geometry to the general literature on radiation configuration factors.
Proton density energy distributions during two magnetic storms on Dec. 16 and 18, 1971, are derived from proton detector data of the S3-A satellite and are analyzed to show the contrast in the ring current developments during the two events. Ground magnetograms are also used in the analysis to show the magnetic field variations during the storms. Satellite orbits 97 through 103 are covered.
The types of wear particles generated by a five-ring polyphenyl ether in boundary lubrication experiments in various atmospheres were determined by ferrographic analysis. The types of wear particles observed included cylindrical or rocklike organometallic debris, adhesive and cutting wear particles, and some spherical debris. Interpretations as to the mechanism of generation of the various types of particles are presented.
Applications in lasers for antiresonant ring interferometer include coupled laser cavities, variable laser-output coupling, intercavity harmonic-output coupling, mode locking, cavity dumping, and pulse code modulation.
The upcoming Mariner Jupiter-Saturn '77 space project is discussed. The variations in radar and radio observations are evaluated, along with particle distribution within the Saturn rings.