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  • LUNAR AND PLANETARY EXPLORATION  (3,679)
  • AERODYNAMICS  (2,110)
  • 1975-1979  (5,789)
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Year
  • 101
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    Ionosphere of Venus - First observations of day-night variations of the ion composition (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Preliminary observations of day-night variations in the ion composition of the ionosphere of Venus, obtained by the Pioneer Venus Orbiter ion mass spectrometer experiment, are reported. A remarkable abundance and extent of ionization in the deep regions of the nightside ionosphere was observed, in spite of the long Venus night. A comparison of dayside and nightside ion distributions reveals a nightside composition similar in several respects to that of the dayside, with the ions O(+) and O2(+) forming the nightside F 2 and F 1 regions, respectively, as in the dayside. Important differences include a greater abundance of low-latitude ionization in the nightside, a significant increase of H(+) and NO(+) ions with increasing solar zenith angle, and extreme dynamic variability of the nightside region above 160 km. Ion composition data support the view that the nightside ionosphere can be maintained by the transport of ionization from the dayside.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 102
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    Venus - Preliminary topographic and surface imaging results from the Pioneer Orbiter (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Three large Venus surface features, identified previously in images obtained from earth-based radar observations, are shown by the Pioneer Venus radar mapper to be elevated 5 to 10 km above the surrounding terrain. Two of these features, one bright and the other dark, lie adjacent to each other astride the 65 N parallel between longitudes 310 E and 10 E. The combined region forms a huge tectonically uplifted plateau, surmounted by radar-bright ridges that may have either a volcanic or tectonic origin. The third feature, located at 30 N, 283 E, is radar-bright and may consist of volcanic material extruded along a fault zone. A first radar-scattering image, compiled from data obtained by the mapper in its imaging mode, shows a region north of the equator; several circular depressions seen in this area may result from meteoritic impact.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 103
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    Nature of the ultraviolet absorber in the Venus clouds - Inferences based on Pioneer Venus data (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Several photometric measurements of Venus made from the Pioneer Venus orbiter and probes indicate that solar near-ultraviolet radiation is being absorbed throughout much of the main cloud region, but little above the clouds or within the first one or two optical depths. Radiative transfer calculations were carried out to simulate both Pioneer Venus and ground-based data for a number of proposed cloud compositions. This comparison rules out models invoking nitrogen dioxide, meteoritic material, and volatile metals as the source of the ultraviolet absorption. Models involving either small (approximately 1 micrometer) or large (approximately 10 micrometers) sulfur particles have same serious difficulties, while ones invoking sulfur dioxide gas appear to be promising.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 104
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    Further results of the Pioneer Venus nephelometer experiment (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Backscattering data for the nephelometer experiments conducted aboard the Pioneer Venus mission probes, including data up to the highest altitudes measured by the probes, are presented. A few small signals were detected below the main cloud deck. Ambient radiation was measured at near-ultraviolet and visible wavelengths; the variation of extinction of near-ultraviolet with altitude is inferred. Ambient radiance decreased more rapidly at 530 than at 745 nanometers in the lower atmosphere.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 105
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    Implications of the gas compositional measurements of Pioneer Venus for the origin of planetary atmospheres (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Comparisons are made between the volatile inventories of the terrestrial planets, including Pioneer Venus data, and the predictions of three classes of theories for the origin of planetary atmospheres. Serious difficulties arise for the primary atmosphere and external source hypotheses. The grain accretion hypothesis can account for the trends in the volatile inventory from Venus to earth to Mars, if volatiles were incorporated into planet-forming grains at nearly the same temperature for all of these planets, but at systematically lower pressures in the regions of planet formation farther from the center of the solar nebula.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 106
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    Venus upper atmosphere neutral gas composition - First observations of the diurnal variations (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Measurements of the composition, temperature, and diurnal variations of the major neutral constituents in the thermosphere of Venus are being made with a quadrupole mass spectrometer on the Pioneer Venus Orbiter. Concentrations of carbon dioxide, carbon monoxide, molecular nitrogen, atomic oxygen, and helium are presented, in addition to an empirical model of the data. The concentrations of the heavy gases, carbon dioxide, carbon monoxide, and molecular nitrogen, rapidly decrease from the evening terminator toward the nightside; the concentration of atomic oxygen remains nearly constant and the helium concentration increases, an indication of a nightside bulge. The kinetic temperature inferred from scale heights drops rapidly from 230 K at the terminator to 130 K at a solar zenith angle of 120 deg, and to 112 K at the antisolar point.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 107
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    Laboratory corroboration of the Pioneer Venus gas chromatograph analyses (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Laboratory simulation and tests of the inlet sampling system and columns of the Pioneer Venus gas chromatograph show that the sensitivity to argon is not diminished after the column regeneration step, that argon isotopes are not separated, that oxygen and sulfur dioxide are not produced in the inlet sampling system from sulfur trioxide, and that sulfur trioxide is not formed from sulfur dioxide and oxygen. Comparisons of the volatile inventory of Venus and earth imply similar efficiencies of early outgassing but a lower efficiency for later outgassing in the case of Venus. The high oxidation state of the Venus atmosphere in the region of cloud formation may prohibit the generation of elemental sulfur particles.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 108
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    Encounter with Venus - An update (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: This report deals with early results from the Pioneer Venus Orbiter and multiprobe missions, which encountered Venus on December 4 and December 9, 1978, respectively. Initial results for the multiprobe mission and for the first 30 days of the Orbiter mission have already been reported. Additional mission features and updated mission parameters based on refined tracking data and trajectory computations are presented here. Scientific results for both missions are discussed which cover the first 130 days (or orbits) of the nominal 243-day Orbiter mission.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 109
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    Thermal contrast in the atmosphere of Venus - Initial appraisal from Pioneer Venus probe data (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The altitude profiles of temperature and pressure were measured during the descent of four Pioneer Venus probes, showing small contrasts below the clouds, but significant differences within the clouds at altitudes from 45 to 61 km. Measurements of pressure differences were found to be consistent with the cyclostrophic balance of zonal winds ranging from 110 to 150 m/sec at 60 km and from 43 to 77 m/sec at 40 km. The clouds were 10 to 20 K warmer than the extended profiles of the lower atmosphere and the middle cloud is convectively unstable. Both phenomena are due to thermal radiation from below. Meridional wind velocities were studied, concluding that significant planetary scale non-axisymmetric motions were present at latitudes below 30 degrees. This result was consistent with the day-night pressure difference. Indications of flow oscillations in the lower atmosphere were noted and the inference of wave motions in the lower atmosphere was supported by analysis of oscillations in the Doppler residuals.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 205; July 6
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  • 110
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    Energetic protons in the Jovian magnetosphere (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Time histories, angular distributions and energy spectra of energetic protons were observed over an energy range of 0.2 to 20 MeV for the four passes of Pioneers 10 and 11 through the Jovian magnetosphere. The energetic particle data from these four passes are remarkably different. Azimuthal anisotropies appear to dominate with time variations also contributing to the very complex topology. On the inbound P-10 pass the expected corotation anisotropy was not observed in the outer magnetosphere. The simplest explanation is that the particle reference frame (the magnetospheric plasma) is moving nearly radially, suggesting the existence of a planetary wind at that time.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; June 1
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  • 111
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    Evidence for lightning on Venus (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Evidence for lightning on Venus obtained by the Pioneer Venus 1 Orbiter is presented. The first indications of lightning were detected by the electric field detector on board the Orbiter when the spacecraft periapsis, which is well within the ionosphere, moved into the night side of the planet. Impulsive wave signals were primarily detected at altitudes less than 25 km, and were found to be strongest at frequencies corresponding to propagation in the whistler mode, occurring at an average rate of about 0.5/sec. The signals were often observed during intervals of low and variable electron densities. It is tentatively concluded on the basis of the above observations that the impulsive events were caused by Venusian lightning.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Nature; 279; June 14
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  • 112
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    Temperature structure of the Uranian upper atmosphere (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The temperature structure of the upper atmosphere of Uranus at two locations on the planet was determined from observations of the occultation of the star SAO158687 by Uranus on 10 March 1977, carried out at the Kuiper Airborne Observatory. The temperature-pressure relationships obtained from the immersion and emersion data for 7280 A channel show peak-to-peak variations of 45 K for immersion and 35 K for emersion. The mean temperature for both immersion and emersion profiles is about 100 K, which shows that Uranus has a temperature inversion between 0.001 mbar and the 100 mbar level probed by IR measurements. Both profiles show wavelike temperature variations, which may be due to dynamical or photochemical processes.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Nature; 278; May 24
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  • 113
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    Magnetic field studies at Jupiter by Voyager 1 - Preliminary results (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Results obtained by the Goddard Space Flight Center magnetometers on Voyager 1 are described. These results concern the large-scale configuration of the Jovian bow shock and magnetopause, and the magnetic field in both the inner and outer magnetosphere. There is evidence that a magnetic tail extending away from the planet on the nightside is formed by the solar wind-Jovian field interaction. This is much like earth's magnetosphere but is a new configuration for Jupiter's magnetosphere not previously considered from earlier Pioneer data. The analysis and interpretation of magnetic field perturbations associated with intense electrical currents (approximately 5 million amperes) flowing near or in the magnetic flux tube linking Jupiter with the satellite Io and induced by the relative motion between Io and the corotating Jovian magnetosphere are reported. These currents may be an important source of heating the ionosphere and interior of Io through Joule dissipation.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Science; 204; June 1
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  • 114
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    On the configuration of the nightside Venus ionopause (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Nightside measurements of electron and ion concentrations by instruments on the Pioneer Venus Orbiter have revealed an ionopause which is highly dynamic and whose global configuration is surprisingly complex. Inbound crossing which occur at high northern latitudes encounter the ionopause at an average altitude of 870 km in the late afternoon sector. The average ionopause altitude increases slightly near 100 deg solar zenith angle (SZA) followed by a nightside compression to well below 500 km. The outbound crossings of the ionopause occur at about 20 deg south of the equator. The ionospause at this latitude is found at an average altitude of 800 km in the afternoon-evening sector between 65 and 110 deg SZA, followed by a pronounced rise to altitudes as high as 3000 km in a pronounced bulge near 130 deg SZA.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters; 6; May 1979
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  • 115
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    Quasi-periodic structure of a turbulent jet (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: The instantaneous near field pressure fluctuations of an axisymmetric subsonic jet were measured by using a longitudinal and an azimuthal microphone arrays in order to qualitatively determine the behaviors of the quasi-periodic structure within the flow. Statistical analysis is used to explain the characteristic of the pressure signals. In addition to the information obtained by forming the power spectral density, auto- and cross-correlation functions, two types of signals are extracted through a conditional probability analysis to represent the quasi-periodic and the random fine structures within the turbulent jet. The quasi-periodic structure first appears as a rolling up of the mixing layer flow within one nozzle diameter downstream of the exit, then becomes fully developed at approximately 3 nozzle diameters downstream with a preferred Strouhal number range 0.3-0.4, and finally disappears beyond the end of potential core. This behavior is also reflected in the variation of the convection velocity.
    Keywords: AERODYNAMICS
    Type: Journal of Sound and Vibration; 64; May 8
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  • 116
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    Tharsis Province of Mars - Geologic sequence, geometry, and a deformation mechanism (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Tharsis development apparently involved two stages: (1) an initial rapid topographic rise accompanied by the development of a vast radial fault system and (2) an extremely long-lived volcanic stage apparently continuing to the geological present. A deformation model is proposed in which a first-order mantle convection cell caused early subcrustal erosion and foundering of the low third of the planet. Underplating and deep intrusion by the eroded materials beneath Tharsis caused isostatic doming. Minor radial gravity motions of surficial layers off the dome produced the radial fault system. The hot underplate eventually affected the surface to cause the very long-lived volcanic second stage.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 38; June 197
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  • 117
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    The effect of surface roughness on the transmission of microwave radiation through a planetary surface (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: To account for surface roughness, the transmission of microwave radiation through a planetary surface to an observer is treated by a Monte Carlo technique. Sizable effects are found near the limb of the planet, and they should be included in analyses of high-resolution observations and high-precision integrated disk observations.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 38; June 197
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  • 118
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    Four-planet meteorology (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: All planets with atmospheres have common characteristics which are helpful in understanding weather and climate on earth. Of the terrestrial planets, Mars displays the most earth-like characteristics. The feedback mechanism of the Martian Great Dust Storms may control climate on a global scale and shows some parallels to the water cycle on the earth. Venus, on the other hand, has atmosphere motions and characteristics far different from those of earth but appears to be valuable for comparative meteorology and it seems to be a simple weather machine due to absence of axial tilt. A completely gaseous Jupiter also can help because its atmosphere, driven by internal heat, flows round-and-round, showing the same general patterns for years at a time. Results of studying extraterrestrial atmospheres are most important for understanding earth's multi-year weather cycles such as the droughts in the American West every 22 years or effects of the Little Ice Age (1450-1915) on agriculture in the North Hemisphere.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Spaceflight; 21; June 197
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  • 119
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    A beaming model of the Io-independent Jovian decameter radiation based on multipole models of the Jovian magnetic field (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A geometrical model is presented in which the apparent source locations of the Io-independent decameter radiation are computed. The calculations assume that the radiation is produced by stably trapped electrons radiating near the local electron gyrofrequency and that the emission is then beamed onto a conical surface. The maximum occurrence probability of noise storms is associated with regions in the Jovian magnetosphere where the axis of the emission cone is most inclined toward the Jovian equatorial plane. The calculations utilize and compare two of the octopole spherical harmonic expansions of the Jovian magnetic field constructed from data accumulated by the fluxgate and vector helium magnetometers on board Pioneer 11.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Astrophysical Journal; vol. 229
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  • 120
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    The seasonal variation of ozone density in the Martian atmosphere (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: A one-dimensional, time-dependent model has been developed to investigate seasonal variations in ozone density in the Martian atmosphere. The model utilizes data for atmospheric temperature, pressure, and water vapor abundance observed by Viking. The results indicate that a high ozone density is not produced near the winter solstice but is in rather late winter, when the amount of water vapor is still small and the solar radiation can penetrate more deeply. A similar condition met in early winter does not necessarily produce a high ozone density because of the predicted higher HO2 density. Seasonal variations in ozone abundance are discussed in terms of the abundances of H2O and H2 and the seasonal variations in their reaction products H2O2 and HOx. The roles of transport, the effects of ozone loss to the surface, and the differences between northern and southern hemisphere ozone distributions are also discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Apr. 1
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  • 121
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    Deep radio occultations and 'evolute flashes' - Their characteristics and utility for planetary studies (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Deep radio occultation signals from spacecraft passing behind planets may provide data on atmospheric absorption, turbulence, and structure, as well as information on the effects of planetary gravitational moments, rotation and zonal winds on the atmospheric shape. The strength of radio signals from a spacecraft passing behind a planet will at first decrease because of defocusing in the atmosphere, but then increase as the evolute of the planetary limb is neared, due to focusing caused by limb curvature within the evolute. Within the evolute, the availability of four simultaneous signal paths over four limb positions may render focused signals instantaneously great. The passage of Voyager 1 behind Jupiter and Voyager 2 behind Saturn will provide a test of deep radio occultation studies.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 37; Mar. 197
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  • 122
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    Climatic change on the terrestrial planets (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Observational data related to climatic change on Venus, earth and Mars are reviewed. The channel features on Mars suggest an early to intermediate epoch of warmer and wetter climate, while the layered polar deposits imply more recent periodic variations in climate. A more reducing atmosphere, which would have produced an enhanced greenhouse effect, may have been responsible for warmer periods in the early history of Mars and earth. Detailed calculations relating atmospheric pressure and composition to the temperature state of Mars are presented. The possibility of a runaway greenhouse effect on Venus resulting in the emplacement of volatiles entirely in the atmosphere is also examined. Periodic variations in orbital eccentricity and axial obliquity may have contributed to alternating glacial and interglacial periods on earth. Mechanisms accounting for the laminated terrain of Mars, and the influence of Martian tectonic distortions on the planet's climate also receive attention.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 37; Mar. 197
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  • 123
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    Martian extratropical cyclones (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Physical properties of summer-season baroclinic waves on Mars are discussed on the basis of vidicon images and infrared thermal mapping generated by Viking Orbiter 1. The two northern-hemisphere storm systems examined here appear to be similar to terrestrial mid-latitude cyclonic storms. The Martian storm clouds are probably composed of water ice, rather than dust or CO2 ice particles.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Nature; 278; Apr. 5
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  • 124
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    Reynolds number effects on the turbulence field in compressible boundary layers (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Detailed experiments were conducted in a zero pressure gradient, supersonic turbulent boundary layer, including measurements of the three components of velocity fluctuations and the turbulent shear stress, for Reynolds numbers ranging from 11.7 million to 105 million at a freestream Mach number of 2.3. The mean flow measurements established the fully developed and equilibrium nature of the boundary layer. Measurements of the turbulence field show that the vertical and transverse fluctuations are essentially equal throughout the boundary layer at all Reynolds numbers, a feature that is different from observations in incompressible flows. The data show that the boundary layer exhibits similarity in the turbulence profiles for the entire Reynolds number range and agrees with previous compressible and incompressible data using Morkovin's scaling to account for compressibility effects.
    Keywords: AERODYNAMICS
    Type: AIAA Journal; 17; Apr. 197
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  • 125
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    On inhomogeneous scattering models of Titan's atmosphere (1979)
    In:  Other Sources
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    Publication Date: 2011-08-17
    Description: Podolak and Danielson (1977) discussed the homogeneous model of Titan's atmosphere with the dust and gas uniformly mixed. They were able to reproduce the equivalent widths of the CH4 bands at 4680 and 5430 A but failed to agree with the observations in the near infrared. The present paper develops an inhomogeneous model which has the dust and gas essentially separated; this model agrees fairly well with the near-IR data of Younkin (1974) but does not agree with the data of Lutz et al. (1976) for the 4860-A band and it must be adjusted to match their data for the 5430-A band.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Icarus; 37; Feb. 197
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  • 126
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    Some steady and oscillating airfoil test results, including the effects of sweep, from the tunnel spanning wing (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A large scale tunnel spanning wing was built and tested. The model can be operated as either a swept or unswept wing and can be tested in steady state or oscillated sinusoidally in pitch about its quarter chord. Data is taken at mid-span with an internal 6-component balance and is also obtained from miniature pressure transducers distributed near the center span region. A description is given of the system and a brief discussion of some of the steady and unsteady results obtained to date. These are the steady load behavior to Mach numbers of approximately 1.1 and unsteady loads, including drag, at a reduced frequency of approximately 0.1.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 445-458
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  • 127
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    A new airfoil research capability (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The design and construction of a self streamlining wall test section for the Langley 0.3 meter transonic cryogenic tunnel was included in the fiscal year 1978 construction of facilities budget for Langley Research Center. The design is based on the research being carried out by M. J. Goodyer at the University of Southampton, Southampton, England, and is supported by Langley Research Center. This paper presents a brief description of the project. Included are some of the design considerations, anticipated operational envelope, and sketches showing the detail design concepts. Some details of the proposed operational mode, safety aspects, and preliminary schedule are presented.
    Keywords: AERODYNAMICS
    Type: Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 425-432
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  • 128
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    Design and calibration of slotted walls for transonic airfoil wind tunnels (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The traditional procedure for estimating the performance of slotted walls for airfoil wind tunnels is reviewed, and a modification which improves the accuracy of this procedure is described. Unlike the traditional procedure, the modified procedure indicates that the design of airfoil wind-tunnel walls which induce minimal blockage and streamline-curvature effects is feasible. The design and testing of such a slotted wall is described. It is shown experimentally that the presence of a model can affect the plenum pressure and thus make the use of the plenum pressure as a calibration reference questionable. Finally, an ONERA experiment which shows the effect of the sidewall boundary layer on the measured model normal force is discussed.
    Keywords: AERODYNAMICS
    Type: Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 433-443
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  • 129
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    Inverse boundary-layer technique for airfoil design (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A description is presented of a technique for the optimization of airfoil pressure distributions using an interactive inverse boundary-layer program. This program allows the user to determine quickly a near-optimum subsonic pressure distribution which meets his requirements for lift, drag, and pitching moment at the desired flow conditions. The method employs an inverse turbulent boundary-layer scheme for definition of the turbulent recovery portion of the pressure distribution. Two levels of pressure-distribution architecture are used - a simple roof top for preliminary studies and a more complex four-region architecture for a more refined design. A technique is employed to avoid the specification of pressure distributions which result in unrealistic airfoils, that is, those with negative thickness. The program allows rapid evaluation of a designed pressure distribution off-design in Reynolds number, transition location, and angle of attack, and will compute an airfoil contour for the designed pressure distribution using linear theory.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 383-397
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    Langley's two-dimensional research facilities: Capabilities and plans (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The current capabilities and the forthcoming plans for Langley's two-dimensional research facilities are described. The characteristics of the Langley facilities are discussed in terms of Reynolds number, Mach number, and angle-of-attack capabilities. Comments are made with regard to the approaches which have been investigated to alleviate typical problem areas such as wall boundary effects. Because of the need for increased Reynolds number capability at high subsonic speeds, a considerable portion of the paper deals with a description of the 20 by 60 cm two-dimensional test section of the Langley 0.3 meter transonic cryogenic tunnel which is currently in the calibration and shakedown phase.
    Keywords: AERODYNAMICS
    Type: Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 399-414
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  • 131
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    The prediction of two-dimensional airfoil stall progression (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A generalized boundary condition potential flow calculation method was combined with a momentum integral boundary layer method and a base flow theory of separation to predict airfoil viscous-inviscid interference up to and beyond stall. The resultant program considers laminar and turbulent separation and is, therefore, applicable to thin or thick airfoil stall. The calculated flow field includes the airfoil and the separation bubble recombination region behind the airfoil. Calculated pressure distributions and equivalent airfoil shapes, including the displacement thickness of the viscous regions, are compared with flow field measurements for several airfoils. The measured displacement thicknesses and wake centerlines corroborate the calculated shape. The comparison also suggests the use of the analytical solution to evaluate the measurements.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 335-345
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  • 132
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    Application of numerical optimization to the design of advanced supercritical airfoils (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: An application of numerical optimization to the design of advanced airfoils for transonic aircraft showed that low-drag sections can be developed for a given design Mach number without an accompanying drag increase at lower Mach numbers. This is achieved by imposing a constraint on the drag coefficient at an off-design Mach number while minimizing the drag coefficient at the design Mach number. This multiple design-point numerical optimization has been implemented with the use of airfoil shape functions which permit a wide range of attainable profiles during the optimization process. Analytical data for the starting airfoil shape, a single design-point optimized shape, and a double design-point optimized shape are presented. Experimental data obtained in the NASA Ames two-by two-foot wind tunnel are also presented and discussed.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 315-325
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  • 133
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    Improved prediction of laminar leading edge separation (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Research was conducted to provide a definite criterion for the prediction of the bubble burst on airfoils typical of those used for fighter wings. The approach taken was to correlate existing airfoil bubble burst data using various parameters at the laminar separation point. The method due to Weber was modified to provide a continuous analytic solution for the velocity distribution around the airfoil leading edge. Coupling the modified Weber method with the Stratford laminar separation prediction method leads to a universal chart giving the conditions at separation as a function of stagnation location and leading edge radius. Application of the combined method to available two-dimensional airfoil data resulted in an empirical criterion presenting the limiting local velocity gradient at separation as a function of the boundary layer momentum thickness at separation for bubble burst. The correlation leads as well to the qualitative explanation of two types of laminar stall: thin airfoil and leading edge. The validity of the correlation is demonstrated by predicting the lift coefficient and angle of attack for stall on airfoils with leading edge or trailing edge flaps.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 327-334
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  • 134
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    Optimization of multi-element airfoils for maximum lift (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Two theoretical methods are presented for optimizing multi-element airfoils to obtain maximum lift. The analyses assume that the shapes of the various high lift elements are fixed. The objective of the design procedures is then to determine the optimum location and/or deflection of the leading and trailing edge devices. The first analysis determines the optimum horizontal and vertical location and the deflection of a leading edge slat. The structure of the flow field is calculated by iteratively coupling potential flow and boundary layer analysis. This design procedure does not require that flow separation effects be modeled. The second analysis determines the slat and flap deflection required to maximize the lift of a three element airfoil. This approach requires that the effects of flow separation from one or more of the airfoil elements be taken into account. The theoretical results are in good agreement with results of a wind tunnel test used to corroborate the predicted optimum slat and flap positions.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt.1; p 237-253
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  • 135
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    Improvements in surface singularity analysis and design methods (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The coupling of the combined source vortex distribution of Green's potential flow function with contemporary numerical techniques is shown to provide accurate, efficient, and stable solutions to subsonic inviscid analysis and design problems for multi-element airfoils. The analysis problem is solved by direct calculation of the surface singularity distribution required to satisfy the flow tangency boundary condition. The design or inverse problem is solved by an iteration process. In this process, the geometry and the associated pressure distribution are iterated until the pressure distribution most nearly corresponding to the prescribed design distribution is obtained. Typically, five iteration cycles are required for convergence. A description of the analysis and design method is presented, along with supporting examples.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 221-236
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  • 136
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    Prospects for computing airfoil aerodynamics with Reynolds averaged Navier-Stokes codes (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The Reynolds averaged Navier-Stokes equations are solved numerically for a variety of transonic airfoil configurations where viscous phenomena are important. Illustrative examples include flows past sensitive geometries, Reynolds number effects, and buffet phenomena.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 119-131
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  • 137
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    Overview of two-dimensional airfoil research at Ames Research Center (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The five basic elements of the two dimensional airfoil research program at Ames Research Center are illustrated. These elements are experimental, theoretical (including computational), validation, design optimization, and industry interaction. Each area is briefly discussed.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 39-44
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  • 138
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    Low speed airfoil design and analysis (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A low speed airfoil design and analysis program was developed which contains several unique features. In the design mode, the velocity distribution is not specified for one but many different angles of attack. Several iteration options are included which allow the trailing edge angle to be specified while other parameters are iterated. For airfoil analysis, a panel method is available which uses third-order panels having parabolic vorticity distributions. The flow condition is satisfied at the end points of the panels. Both sharp and blunt trailing edges can be analyzed. The integral boundary layer method with its laminar separation bubble analog, empirical transition criterion, and precise turbulent boundary layer equations compares very favorably with other methods, both integral and finite difference. Comparisons with experiment for several airfoils over a very wide Reynolds number range are discussed. Applications to high lift airfoil design are also demonstrated.
    Keywords: AERODYNAMICS
    Type: Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 73-100
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  • 139
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    Langley airfoil-research program (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: An overview of past, present, and future airfoil research activities at the Langley Research Center is given. The immediate past and future occupy most of the discussion; however, past accomplishments and milestones going back to the early NACA years are dealt with in a broad-brush way to give a better perspective of current developments and programs. In addition to the historical perspective, a short description of the facilities which are now being used in the airfoil program is given. This is followed by a discussion of airfoil developments, advances in airfoil design and analysis tools (mostly those that have taken place over the past 5 or 6 years), and tunnel-wall-interference predictive methods and measurements. Future research requirements are treated.
    Keywords: AERODYNAMICS
    Type: Advanced Technol. Airfoil Res., Vol. 1, Pt. 1; p 11-38
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  • 140
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    Comet Halley and history (1979)
    In:  CASI
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    Publication Date: 2017-10-02
    Description: A history of Halley's Comet is presented. Comets Kohoutek and Ikeya-Seki are discussed.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 179-196
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  • 141
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    Prediction of aerodynamic characteristics for slender bodies alone and with lifting surfaces to high angles of attack (1979)
    In:  CASI
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    Publication Date: 2017-10-02
    Description: A method is presented for computing normal force and pitching moment coefficients for slender bodies of circular and noncircular cross section alone and with lifting surfaces. A semiempirical term representing viscous-separation crossflow is added to a term representing potential-theory crossflow. For bodies of revolution, computed aerodynamic characteristics agree with measured results for investigated free-stream Mach numbers from 0.6 to 2.9 and for angles of attack from 0 deg to 180 deg. For bodies of elliptic cross section, measured results are predicted well over the investigated Mach number range from 0.6 to 2.0 and the angle range from 0 deg to 60 deg. For all bodies the predictions are best at supersonic Mach numbers. For body-wing and body-wing-tail configurations, measured normal force coefficients and centers are predicted at the upper test Mach number of 2.0. As the Mach number is decreased to 0.6, the agreement for the normal-force coefficients rapidly deteriorates. When model flow-separation and vortex patterns are asymmetric, undesirable side forces are usually measured on the models at subsonic Mach numbers and zero sideslip angle. Generally, the side-force coefficients decrease or vanish with: increase in Mach number, decrease in nose fineness ratio, nose blunting, and flattening of body cross section.
    Keywords: AERODYNAMICS
    Type: AGARD High Angle of Attack Aerodyn.; 40 p
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  • 142
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    Recent theoretical developments and experimental studies pertinent to vortex flow aerodynamics, with a view towards design (1979)
    In:  CASI
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    Publication Date: 2017-10-02
    Description: Recent progress in a research program directed toward an improved vortex flow technology base was reviewed. Analysis methods for conical flow and analysis and design methods for nonconical flows are presented. Applications are made for a variety of planar, nonplanar, and interferring lifting surfaces. Several methods are shown to provide reasonable estimates of over-all forces and moments for simple wing planforms with the suction analogy method currently offering the most versatility for arbitrary configuration applications. For the prediction of surface loadings the free vortex sheet method being developed by Boeing is shown to have considerable promise and further development of this type of method is encouraged. A data base for ogee strake-wing configurations is summarized with an emphasis on the requirements for maximizing the interference lift. A strake planform design procedure is discussed and a first solution (gothic in planview) is integrated with a wing body. The data show the strake to exhibit expected stable vortex characteristics. It was found that, apart from increasing sweep, conically cambered delta wings developed drag levels approaching that of attached flow with increasing either the lift or the wing camber height, lastly, an approximate vortex flow design method, based on the suction analogy, is outlined and an example is given.
    Keywords: AERODYNAMICS
    Type: AGARD High Angle of Attack Aerodyn.; 31 p
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  • 143
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    The Mechanism of Fluid Resistance (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The mechanism of fluid resistance within the limit of the square law is presented. It was concluded that the investigations should be extended and completed in two directions, namely: by an investigation of stable vortex configurations in space, and by considering the perfect fluid as the limiting case of a viscous fluid and then limiting the law of vortex of formation with the condition that only those fluid particles which were in contact with the surface of the body can receive rotation.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Classical Aerodyn. Theory; p 57-66
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  • 144
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    Considerations of some critical ejector problems (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Some aspects of ejector design and application, including, three dimensional effects and cross flow effects are presented.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 363-384
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  • 145
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    Large-scale turbulent structures in jets and in flows over cavities and their relationship to entrainment and mixing (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Large scale structures in jets and in flows over cavities were investigated experimentally to determine their role in entrainment, mixing, and noise production. The presence of these structures resulted in growth of the shear layer and entrainment. Merging of adjacent large scale structures caused the near field pressure signal in excited flows. It is believed that both the entrained fluid as well as its eventual mixing with the jet flow can be controlled by introducing pulsation in the jet flow at a frequency for which the flow is most unstable.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 295-309
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  • 146
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    Recent developments in ejector technology in the Air Force: An overview (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Basic and applied studies in thrust augmentation conducted at the Aerospace Research Laboratory at Wright-Patterson AFB which led to an effective configuration of the jet flap diffuser ejector, are reviewed. A method for compressible ejector flow analysis, developed in support of the preliminary design of an ejector thrust aircraft, is discussed and applied to single- and two-stage ejectors.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 1-22
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  • 147
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    A Comparison of the Aerodynamic Characteristics of Eight Sailwing Airfoil Sections (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The operational characteristics of sailwings are discussed with emphasis placed on the importance of the trailing edge cable tension. The three dimensional aerodynamic characteristics were obtained from wind tunnel tests, and the results compared to determine the magnitude of the aerodynamic penalties paid for various structural simplifications. For the sectional thickness ratios, it is concluded that, while the basic double-membraned sailwing has exceptional aerodynamic performance, even superior for some applications to the conventional hardwing, any notable deviation from this configuration results in an unacceptably large performance penalty.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 155-176
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  • 148
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    Low-speed single-element airfoil synthesis (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The use of recently developed airfoil analysis/design computational tools to clarify, enrich and extend the existing experimental data base on low-speed, single element airfoils is demonstrated. A discussion of the problem of tailoring an airfoil for a specific application at its appropriate Reynolds number is presented. This problem is approached by use of inverse (or synthesis) techniques, wherein a desirable set of boundary layer characteristics, performance objectives, and constraints are specified, which then leads to derivation of a corresponding viscous flow pressure distribution. Examples are presented which demonstrate the synthesis approach, following presentation of some historical information and background data which motivate the basic synthesis process.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 1-31
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  • 149
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    The external augmentor concept for V/STOL aircraft (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The beneficial aspects of an ejector powered V/STOL concept were reviewed. The feasibility of satisfactorily incorporating an ejector system in a high performance V/STOL aircraft was investigated. The external augmentor concept, based on the use of chordwise ejector slots, is presented. It is concluded that the external augmentor concept has a basic inherent simplicity and a sufficient augmentor performance potential to make feasible a high performance V/STOL aircraft based on ejectors.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 449-471
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  • 150
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    Ion propulsion and Comet Halley rendezvous (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Cometary rendezvous missions using ion propulsion is considered. The characteristics of the ion engine are discussed including the fuel efficiency and acceleration, and the design of the ion engine is described. The operation of the ion drive engine and an overview of its applications are presented.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 197-214
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  • 151
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    Interface concerns of ejector integration in V/STOL aircraft (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A number of areas which have in the past contributed to weight, complexity, and thrust losses in the ejector-powered V/STOL vehicle were identified. Most of these interfaces taken singly do not represent a severe compromise to the vehicle; however, the bottom line is that the sum of compromises and the subsequent effects on performance, flight operations and maintenance have rendered the ejector V/STOL aircraft unattractive. In addition to some of the unique ejector/aircraft integration problems, the vehicle by virtue of having a V/STOL capability, is compromised in other areas. To be successful and acceptable, the advantages must outweight the disadvantages and simplicity with minimum penalties must be the rule. It is concluded that more emphasis must be placed on the ejector/aircraft interface for the concept to be successful.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 397-415
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  • 152
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    Entrainment characteristics of unsteady subsonic jets (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The effectiveness of jet unsteadiness in enhancing flow entrainment was assessed. It was conducted that entrainment depends on the type and amount of jet unsteadiness. Apparently, the mere introduction of jet unsteadiness by small sinusoidal flow angle variations is insufficient to enhance entrainment but, it should be noted that the results were obtained at measuring stations which are all many nozzle widths downstream of the jet nozzle. Thus, no fully conclusive statement can be made at this time about the entrainment close to the nozzle. The high entrainment of the fluidically oscillated jet was caused by the high-frequency content of this square wave type of oscillation but more detailed measurements are clearly needed, in particular for the fluidically oscillated and the pulsed jets. Practical ejector application requires the proper trade-off between entrainment and primary nozzle thrust efficiency.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 311-324
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  • 153
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    Some tests on small-scale rectangular throat ejector (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A small scale rectangular throat ejector with plane slot nozzles and a fixed throat area was tested to determine the effects of diffuser sidewall length, diffuser area ratio, and sidewall nozzle position on thrust and mass augmentation. The thrust augmentation ratio varied from approximately 0.9 to 1.1. Although the ejector did not have good thrust augmentation performance, the effects of the parameters studied are believed to indicate probable trends in thrust augmenting ejectors.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 239-251
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  • 154
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    An Exploratory Investigation of the Effect of Plastic Coating on the Profile Drag of a Practical-Metal-Construction Sailplane Airfoil (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: An exploratory investigation was performed in the Langley low-turbulence pressure tunnel to determine the effect of a plastic coating on the profile drage of a practical-metal-construction sailplaine airfoil. The mode was tested with three surface configurations: (1) filled, painted, and sanded smooth; (2) rough bare metal; and (3) plastic-coated. The investigation was conducted at Reynolds numbers based on airfoil chord of 1,100,000, 2,200,000, and 3,300,000 at a constant Mach number of 0.10. The results indicate that, at all three Reynolds numbers, the order of the drag values of the three surface configurations, starting with the highest drag, was: filled, painted, and sanded smooth; rough bare metal; and plastic-coated.
    Keywords: AERODYNAMICS
    Type: The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 33-64
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  • 155
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    Comets, carbonaceous chondrites, and interstellar clouds: Condensation of carbon (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Comets, carbonaceous chondrites, and interstellar clouds are discussed in relation to information on interstellar dust. The formation and presence of carbon in stars, comets, and meteorites is investigated. The existence of graphite in the interstellar medium, though it is predicted from thermodynamic calculations, is questioned and the form of carbon contained in comets is considered.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 113-137
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  • 156
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    A simple apparatus for the experimental study of non-steady flow thrust-augmenter ejector configurations (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A flexible, and easily modified, test rig is described which allows a one dimensional nonsteady flow stream to be generated, economically from a steady flow source of compressed air. This nonsteady flow is used as the primary stream in a nonsteady flow ejector constituting part of the test equipment. Standard piezo-electric pressure transducers etc. allow local pressures to be studied, as functions of time, in both the primary and secondary (mixed) flow portions of the apparatus. Provision is also made for measuring the primary and secondary mass flows and the thrust generated. Sample results obtained with the equipment are presented.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejector; p 325-349
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  • 157
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    Nonsteady-Flow Thrust Augmenting Ejectors (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: Ejector augmenters in which the transfer of mechanical energy from the primary to the secondary flow takes place through the work of interface pressure forces are investigated. Nonsteady flow processes are analyzed from the standpoint of energy transfer efficiency and a comparison of a rotary jet augmenter to an ejector is presented.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 187-203
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  • 158
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    Numerical prediction of 3-D ejector flows (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The use of parametric flow analysis, rather than parametric scale testing, to support the design of an ejector system offers a number of potential advantages. The application of available 3-D flow analyses to the design ejectors can be subdivided into several key elements. These are numerics, turbulence modeling, data handling and display, and testing in support of analysis development. Experimental and predicted jet exhaust for the Boeing 727 aircraft are examined.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 55-70
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  • 159
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    The XFV-12A Thrust-Augmented Wing (TAW) prototype aircraft (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The XFV-12A, a unique V/STOL technology prototype aircraft being developed for the Navy, is described. The innovative design features a thrust augmented wing and a canard ejector. Structural, functional, and control test performances are discussed. Static tether test results are also discussed. Assessment of test results are given along with projections for future modification areas.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 473-480
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  • 160
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    Scientific returns from a program of space missions to comets (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A program of cometary missions is proposed. The nature and size of interstellar dust, its origin and evolution; identification of new interstellar molecules; clarification of interstellar chemistry; accretion of grains into protosolar cometesimals; role of a T Tauri wind in the dissipation of the protosolar nebula; record of isotopic anomalies, better preserved in comets than in meteorites; cosmogenic and radiogenic dating of comets; cosmochronology and mineralogy of meteorites, as compared with that of cometary samples; origin of the earth's biosphere, and the origin of life are topics discussed in relation to comet exploration.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 139-178
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  • 161
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    Comets: Cosmic connections with carbonaceous meteorites, interstellar molecules and the origin of life (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The ions, radicals, and molecules observed in comets may be derived intact or by partial decomposition from parent compounds of the sort found either in the interstellar medium or in carbonaceous meteorites. The early loss of highly reducing primitive atmosphere and its replacement by a secondary atmosphere dominated by H2O, CO2, and N2, as depicted in current models of the earth's evolution, pose a dilemma for the origin of life: the synthesis of organic compounds necessary for life from components of the secondary atmosphere appears to be difficult, and plausible mechanisms have not been evaluated. Both comets and carbonaceous meteorites are implicated as sources for the earth's atmophilic and organogenic elements. A mass balance argument involving the estimated ratios of hydrogen to carbon in carbonaceous meteorites, comets, and the crust and upper mantle suggests that comets supplied the earth with a large fraction of its volatiles. The probability that comets contributed significantly to the earth's volatile inventory suggests a chemical evolutionary link between comets, prebiotic organic synthesis, and the origin of life.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 59-111
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  • 162
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    Reaction control system augmentation for V/STOL aircraft (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Advantages and problems associated with augmentation of reaction controls are discussed. The current status of compact ejector technology and the expected performance of known efficient designs for reaction control applications are presented.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 417-436
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  • 163
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    On the rational design of compressible flow ejectors (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A fluid mechanics review of chemical laser ejectors is presented. The characteristics of ejectors with single and multiple driver nozzles are discussed. Methods to compute an optimized performance map in which secondary Mach number and performance are computed versus mass ratio, to compute the flow distortion at each optimized condition, and to determine the thrust area for the design point to match diffuser impedence are examined.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center. Workshop on Thrust Augmenting Ejectors; p 109-139
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  • 164
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    An overview of current Navy programs to develop thrust augmenting ejectors (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The primary objective of Navy sponsored research in thrust augmentation is the development of an improved augmenter for V/STOL application. In support of this goal, a data base is being established to provide an accurate prediction capability for use in ejector design. A general technology development of ejectors and associated effects presently is split into the more specific areas of lift and control, since thrust augmenting ejectors may be suitable for both. Research areas examined include advanced diffuser and end wall design; advanced primary nozzles; analytic studies; augmenting reaction controls; and nozzle design.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 41-54
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  • 165
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    NASA overview (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The history of NASA efforts at Ames Research Center in researching the performance and application of thrusting augmentors is reviewed. Current objectives include: (1) parametric description of thrust augmentor application to STOL and V/STOL; (2) the use of theoretical and empirical data; (3) aircraft-augmentor integration; and (4) key design considerations for STOL transport and V/STOL fighter aircraft. Test facilities are described and ejector development and performance are assessed.
    Keywords: AERODYNAMICS
    Type: Workshop on Thrust Augmenting Ejectors; p 23-40
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  • 166
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    Scientific need for a cometary mission (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Known facts about comets are reviewed including their organic and inorganic content. Photographs are used to show the differences in the physical appearances of the three types of comets. Space missions will provide the opportunity to determine the sequence of events that led to their formation and that of the solar system; how volatiles arrived on earth; and the basis for the existence of life on earth; and the source of the outer planetary system.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 1-31
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  • 167
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    Design and test of a prototype scale ejector wing (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A two dimensional momentum integral analysis was used to examine the effect of changing inlet area ratio, diffuser area ratio, and the ratio of ejector length to width. A relatively wide range of these parameters was considered. It was found that for constant inlet area ratio the augmentation increases with the ejector length, and for constant length: width ratio the augmentation increases with inlet area ratio. Scale model tests were used to verify these trends and to examine th effect of aspect ratio. On the basis of these results, an ejector configuration was selected for fabrication and testing at a scale representative of an ejector wing aircraft. The test ejector was powered by a Pratt-Whitney F401 engine developing approximately 12,000 pounds of thrust. The results of preliminary tests indicate that the ejector develops a thrust augmentation ratio better than 1.65.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 437-448
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  • 168
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    Coannular supersonic ejector nozzles (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The nozzles described exhibit a flow field which is supersonic except for the initial flow region, and the secondary mass flow is typically about five percent of the primary core flow. The features to improve the accuracy of the performance calculations are discussed. A special calculation is made to get as realistic a sonic line as possible for this geometry, using an analysis developed by Brown. The mixing between the secondary and core flows is treated to account for entrainment of the secondary flow into core. Both of these phenomena directly affect the pressure distribution on the shroud and therefore, the thrust that the nozzle produces. The importance of using a realistic sonic line and a mixing analysis is stressed.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 385-396
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  • 169
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    Integration of ejectors into high-speed aircraft (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: The integration of ejectors into forebodies is considered for transonic and supersonic flight. Topics discussed include mixing flow in ducts, prediction of flow fields and external aerodynamics.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 225-238
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  • 170
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    Augmenting ejector endwall effects (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Rectangular inlet ejectors which had multiple hypermixing nozzles for their primary jets were investigated for the effects of endwall blowing on thrust augmentation performance. The ejector configurations tested had both straight wall and active boundary layer control type diffusers. Endwall flows were energized and controlled by simple blowing jets suitably located in the ejector. Both the endwall and boundary layer control diffuser blowing rates were varied to determine optimum performance. High area ratio diffusers with insufficient endwall blowing showed endwall separation and rapid degradation of thrust performance. Optimized values of diffuser boundary layer control and endwall nozzle blowing rates in an ejector augmenter were shown to achieve high levels of augmentation performance for maximum compactness.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting Ejectors; p 253-271
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  • 171
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    Internal-external flow integration for a thin ejector-flapped wing section (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.
    Keywords: AERODYNAMICS
    Type: NASA. Ames Res. Center Workshop on Thrust Augmenting
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  • 172
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    Wind tunnel tests of four flexible wing ultralight gliders (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The aerodynamic lift, drag, and pitching moment characteristics of four full scale, flexible wing, ultralight gliders were measured in the settling chamber of a low speed wind tunnel. The gliders were tested over a wide range of angle of attack and at two different velocities. Particular attention was devoted to the lift and pitching moment behavior at low and negative angles of attack because of the potential loss of longitudinal stability of flexible wing gliders in this regime. The test results were used to estimate the performance and longitudinal control characteristics of the gliders.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center Sci. and Technol. of Low Speed and Motorless Flight; p 557-589
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  • 173
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    Some new airfoils (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A computer approach to the design and analysis of airfoils and some common problems concerning laminar separation bubbles at different lift coefficients are briefly discussed. Examples of application to ultralight airplanes, canards, and sailplanes with flaps are given.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 131-154
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  • 174
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    Generation and breakdown of aerodynamic lift: Physical mechanism (1979)
    In:  CASI
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    Publication Date: 2016-06-07
    Description: A contribution is given to an old problem: the explanation of the generation of aerodynamic lift. Physical models are described which provide a better understanding of the phenomena involved.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 93-102
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  • 175
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    Length and bursting of separation bubbles: A physical interpretation (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: A physical interpretation of the observed form of the pressure distribution beneath a two-dimensional separation bubble which modified the external inviscid pressure distribution only locally is given in terms of boundary layer concepts. A simple method for estimating along a mean streamline entrained into the underside of a growing shear layer through the transition region is discussed, and predictions of bubble bursting conditions and a lower bound on the bubble length are compared with experiment.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 177-202
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  • 176
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    The effect of disturbance on a wing (1979)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Disturbances such as flap and aileron hinges and poorly faired spoilers were simulated in a computer wind tunnel. The total drag of a single roughness element does not depend only on the size of that element. Its position on the wing has a surprisingly strong effect. In particular, a roughness element on the convex side of a deflected flap or aileron causes a very substantial increase in drag. Very few experimental data are available for comparison. Good agreement with experiment can be achieved, however, by adapting a fictive step size. The correlation between the real roughness-element size and the drag increase remains to be determined. Simple, fundamental experiments are suggested which will allow a theoretical estimation of the drag increase due to roughness elements.
    Keywords: AERODYNAMICS
    Type: NASA. Langley Res. Center The Sci. and Technol. of Low Speed and Motorless Flight, Pt. 1; p 81-92
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  • 177
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    Connections between comets and plasmas in space (1979)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: The dynamical processes in the cometary system represent unusual examples of very important, widespread natural phenomena. Topics covered include: (1) the comet as an obstacle in the solar wind; (2) the nature of the plasma flow; (3) collisionless shocks; and (4) plasma processes in the comet tail.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: NASA. Goddard Space Flight Center Space Missions to Comets; p 33-58
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  • 178
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    Convection and lunar thermal history (1979)
    In:  Other Sources
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    Publication Date: 2019-04-02
    Description: The effects of solid interior convection on the thermal history of the moon are examined. Convective models of lunar evolution are calculated to demonstrate the influence of various viscosities, radioactive heat source distributions and initial temperature profiles and tested by means of a thermal history simulation code. Results indicate that solid convection does not necessarily produce a quasi-steady thermal balance between heat sources and surface losses. The state of the lithosphere is found to be sensitive to the efficiency of heat source redistribution, while that of the convecting interior depends primarily on rheology. Interior viscosities of 10 to the 21st to 10 to the 22nd cm/sec are obtained, along with a central temperature above 1100 C. It is suggested that mare flooding could have been the result of magma production by pressure release melting in the upwelling region of convection cells.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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  • 179
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    Solid Convection in the Terrestrial Planets; Workshop, NASA Ames Research Center, Moffett Field, Calif., December 12, 13, 1977, Review Papers and Contributions (1979)
    In:  Other Sources
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    Publication Date: 2019-03-30
    Description: Review papers and specific contributions on the subject of convection in the solid interiors of the terrestrial planets and planetary evolution are presented. Geophysical observations of solid-state convection in the terrestrial planets are reviewed, along with the theory of convection in a layer with a high Prandtl number and numerical approaches to the calculation of convection in planetary interiors. Other papers treat the formation, history and energetics of terrestrial planet cores, the effects of convection on lunar thermal history and the relation between the height of mountains on Venus and the creep properties of Venusian rocks.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Physics of the Earth and Planetary Interiors (ISSN 0031-9201); 19; 2; 107-207
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  • 180
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    Kinematics and dynamics of vortex rings in a tube (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Kinematic theory and flow visualization experiments were combined to examine the dynamic processes which control the evolution of vortex rings from very low to very high Reynolds numbers, and to assess the effects of the wall as a vortex ring travels up a tube. The kinematic relationships among the size, shape, speed, and strength of vortex rings in a tube were computed from the theory. Relatively simple flow visualization measurements were used to calculate the total circulation of a vortex rings at a given time. Using this method, the strength was computated and plotted as a function of time for experimentally produced vortex rings. Reynolds number relationships are established and quantitative differences among the three Reynolds number groups are discussed.
    Keywords: AERODYNAMICS
    Type: NASA-CR-166185 , SU-JIAA-TR-26
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  • 181
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    A higher order panel method for linearized supersonic flow (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The basic integral equations of linearized supersonic theory for an advanced supersonic panel method are derived. Methods using only linear varying source strength over each panel or only quadratic doublet strength over each panel gave good agreement with analytic solutions over cones and zero thickness cambered wings. For three dimensional bodies and wings of general shape, combined source and doublet panels with interior boundary conditions to eliminate the internal perturbations lead to a stable method providing good agreement experiment. A panel system with all edges contiguous resulted from dividing the basic four point non-planar panel into eight triangular subpanels, and the doublet strength was made continuous at all edges by a quadratic distribution over each subpanel. Superinclined panels were developed and tested on s simple nacelle and on an airplane model having engine inlets, with excellent results.
    Keywords: AERODYNAMICS
    Type: NASA-CR-3062 , D6-48058
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  • 182
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    A theoretical investigation of ground effects on USB configurations (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A formulation predicts the variation of circulation forces and jet reaction forces in ground proximity as a function of ground height. The predicted results agree well with available experimental data. It is shown that the wing-alone theory is not capable of predicting the ground effect for USB configurations.
    Keywords: AERODYNAMICS
    Type: NASA-CR-159005 , CRINC/FRL-281-3
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  • 183
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    A three-dimensional viscous/potential flow interaction analysis method for multi-element wings: Modifications to the potential flow code to allow part-span, high-lift devices and close-interference calculations (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The description of the modified code includes details of a doublet subpanel technique in which panels that are close to a velocity calculation point are replaced by a subpanel set. This treatment gives the effect of a higher panel density without increasing the number of unknowns. In particular, the technique removes the close approach problem of the earlier singularity model in which distortions occur in the detailed pressure calculation near panel corners. Removal of this problem allowed a complete wake relaxation and roll-up iterative procedure to be installed in the code. The geometry package developed for the new technique and also for the more general configurations is based on a multiple patch scheme. Each patch has a regular array of panels, but arbitrary relationships are allowed between neighboring panels at the edges of adjacent patches. This provides great versatility for treating general configurations.
    Keywords: AERODYNAMICS
    Type: NASA-CR-152277
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  • 184
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    Low-speed aerodynamic characteristics of a 13 percent thick medium speed airfoil designed for general aviation applications (1979)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Wind tunnel tests were conducted to determine the low speed, two dimensional aerodynamic characteristics of a 13percent thick medium speed airfoil designed for general aviation applications. The results were compared with data for the 13 percent thick low speed airfoil. The tests were conducted over a Mach number range from 0.10 to 0.32, a chord Reynolds number range from 2.0 x 10 to the 6th power to 12.0 x 10 to the 6th power, and an angle of attack frange from about -8 deg to 10 deg. The objective of retaining good high-lift low speed characteristics for an airfoil designed to have good medium speed cruise performance was achieved.
    Keywords: AERODYNAMICS
    Type: NASA-TP-1498 , L-12976
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  • 185
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    Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Molecular Evolution; 14; Dec. 197
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  • 186
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    The distribution of lobate debris aprons and similar flows on Mars (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Planet-wide mapping of lobate debris aprons and other similar flows on Mars shows a strong concentration in two latitudinal bands roughly 25 deg wide and centered at 40 deg N and 45 deg S. This distribution supports the idea that these flows form when erosional debris is transported downslope and becomes mixed with ice deposited from the atmosphere, as these latitudes should receive high seasonal H2O frost deposition relative to the rest of the planet. Flows are found in the northern hemisphere band wherever old highland surfaces occur but are found in the southern hemisphere only near the two major impact basins, Argyre and Hellas. These areas are apparently characterized by mass wasting that is rapid relative to most of the southern hemisphere highlands. The rate of mass wasting may be related to the degree of consolidation of highland material.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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  • 187
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    Impact crater and basin control of igneous processes on Mars (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The possible role of impact craters in controlling local Martian endogenic activity is reviewed. Martian impact craters exhibiting evidence for endogenic modification are considered, including the style of modification. In addition, the cooling history of a mafic body intruded beneath impact craters of different sizes which contain water-ice deposits are examined, and results are related to modified Martian craters. This analysis is extended to basin-sized structures, and evidence for impact basin control of major volcanic and tectonic provinces is considered.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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  • 188
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    Plains and channels in the Lunae Planum-Chryse Planitia region of Mars (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: The Lunae Planum-Chryse Planitia region provides the opportunity to study a sequence of channeling events and to determine their temporal and genetic relationships to plains units in the northern hemisphere of Mars. Two sets of small channels and four major channel systems can be divided into four periods of channeling by superposition and contact relationships to the plains. All of the channels are considered to have formed by water erosion. The first two channeling events occurred early in the history of this area and formed small, narrow channels within the old rugged terrain. These channel events were separated by deposition of a mantle unit. The small channels probably formed by runoff of surface water or by a sapping process. These channels preceded the emplacement of vast volcanic plains in both Lunae Planum and Chryse Planitia. Channels postdating the plains are Vedra, Maumee, Bahram, and Maja valles; the first three of these deposited a sedimentary unit on the western slope of Chryse Planitia that was eroded by Maja Vallis. These large-scale channels were probably formed predominantly by catastrophic floods and may represent two periods of water release from Juventae Chasma. The origin of Bahram Vallis remains uncertain.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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  • 189
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    Development and analysis of a twelfth degree and order gravity model for Mars (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: Satellite geodesy techniques previously applied to artificial earth satellites have been extended to obtain a high-resolution gravity field for Mars. Two-way Doppler data collected by 10 Deep Space Network (DSN) stations during Mariner 9 and Viking 1 and 2 missions have been processed to obtain a twelfth degree and order spherical harmonic model for the martian gravitational potential. The quality of this model was evaluated by examining the rms residuals within the fit and the ability of the model to predict the spacecraft state beyond the fit. Both indicators show that more data and higher degree and order harmonics will be required to further refine our knowledge of the martian gravity field. The model presented shows much promise, since it resolves local gravity features which correlate highly with the martian topography. An isostatic analysis based on this model, as well as an error analysis, shows rather complete compensation on a global (long wavelength) scale. Though further model refinements are necessary to be certain, local (short wavelength) features such as the shield volcanos in Tharsis appear to be uncompensated. These are interpreted to place some bounds on the internal structure of Mars.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 30
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  • 190
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    Silicon compounds in the Jupiter atmosphere (1979)
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    Publication Date: 2019-06-27
    Description: The formation of colored silicon compounds under nonequilibrium conditions is discussed with reference to the composition of the Jupiter atmosphere. It is shown that many of these reactions produce strongly colored intermediates that are relatively stable and similar in appearance to those observed on Jupiter. It is suggested that the silicon compounds could substantially contribute to the colors observed on Jupiter. The colored intermediates may be the result of relatively rapid amorphous silicon monoxide formation in vertical atmospheric currents in the region near the red spot and in the red spot itself.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Zeitschrift fuer Naturforschung; vol. 34
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  • 191
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    Integral equations for flows in wind tunnels (1979)
    In:  Other Sources
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    Publication Date: 2019-06-27
    Description: This paper surveys recent work on the use of integral equations for the calculation of wind tunnel interference. Due to the large number of possible physical situations, the discussion is limited to two-dimensional subsonic and transonic flows. In the subsonic case, the governing boundary value problems are shown to reduce to a class of Cauchy singular equations generalizing the classical airfoil equation. The theory and numerical solution are developed in some detail. For transonic flows nonlinear singular equations result, and a brief discussion of the work of Kraft and Kraft and Lo on their numerical solution is given. Some typical numerical results are presented and directions for future research are indicated.
    Keywords: AERODYNAMICS
    Type: Journal of Integral Equations; 1; Sept
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  • 192
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    Scientific exploration of the moon (1979)
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    Publication Date: 2019-06-27
    Description: The paper reviews efforts undertaken to explore the moon and the results obtained, noting that such efforts have involved a successful interdisciplinary approach to solving a number of scientific problems. Attention is given to the interactions of astronomers, cartographers, geologists, geochemists, geophysicists, physicists, mathematicians and engineers. Earth based remote sensing and unmanned spacecraft such as the Ranger and Surveyor programs are discussed. Emphasis is given to the manned Apollo missions and the results obtained. Finally, the information gathered by these missions is reviewed with regards to how it has increased understanding of the moon, and future exploration is considered.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Interdisciplinary Science Reviews; 4; Sept
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  • 193
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    Griffith diffusers (1979)
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    Publication Date: 2019-06-27
    Description: Contoured wall diffusers are designed by using an inverse method. The prescribed wall velocity distribution(s) was taken from the high lift airfoil designed by A. A. Griffith in 1938; therefore, such diffusers are named Griffith diffusers. First the formulation of the inverse problem and the method of solution are outlined. Then the typical contour of a two-dimensional diffuser and velocity distributions across the flow channel at various stations are presented. For a Griffith diffuser to operate as it is designed, boundary layer suction is necessary. Discussion of the percentage of through-flow required to be removed for the purpose of boundary layer control is given. Finally, reference is made to the latest version of a computer program for a two-dimensional diffuser requiring only area ratio, nondimensional length and suction percentage as inputs.
    Keywords: AERODYNAMICS
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  • 194
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    Pyroxenes from planetary basalts - Characterization of 'other' than quadrilateral components (1979)
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    Publication Date: 2019-06-27
    Description: The paper reports on a synthesis of the silicate mineralogy of a planetary basalt suite, which concerns itself only with specific aspects of pyroxene cation substitutional couples. Consideration is given to the mineral chemistry and the basalt suites in an overview fashion. Attention is given to those characteristics of pyroxene chemistry that reflect planetary constraints on the host basalts from which the pyroxenes crystallized. It is concluded that the inspection of a large number of high quality silicate analyses of pyroxenes demonstrates conclusively that these phases carry a signature of the planetary body in which they evolved. In addition, it is noted that there are planetary probes capable of constraining thermodynamic parameters that were obtained during the petrogenesis of their host basaltic liquids
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Geophysical Research Letters; 6; Dec. 197
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  • 195
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    Organic chemistry on Titan (1979)
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    Publication Date: 2019-06-27
    Description: Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Review of Geophysics and Space Physics; 17; Nov. 197
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  • 196
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    Lifting three-dimensional wings in transonic flow (1979)
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    Publication Date: 2019-06-27
    Description: The far field of a lifting three-dimensional wing in transonic flow is analysed. The boundary-value problem governing the flow far from the wing is derived by the method of matched asymptotic expansions. The main result is to show that corrections which are second order in the near field make a first-order contribution to the far field. The present study corrects and simplifies the work of Cheng and Hafez (1975) and Barnwell (1975).
    Keywords: AERODYNAMICS
    Type: Journal of Fluid Mechanics; 95; Nov. 28
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  • 197
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    Io's sodium cloud - Explanation of the east-west asymmetries (1979)
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    Publication Date: 2019-06-27
    Description: An explanation of the east-west asymmetries of Io's sodium clouds is suggested based upon the force experienced by sodium atoms as they resonantly scatter sunlight and upon the ability of this force to alter the cloud atom orbits, as determined by the gravitational fields of Io and Jupiter. Orbit calculations illustrating the time-dependent changes in the sodium atom trajectories produced by the solar radiation force as a function of Io's orbital location are presented in support of this explanation. This theory agrees with the idea that sodium atoms are emitted from the satellite nonisotropically and at a constant rate. These conclusions may be important in studying the global effects of active volcanoes and the intense satellite plasma torus discovered for Io from Voyager I spacecraft measurements.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Astrophysical Journal; vol. 234
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  • 198
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    Atmospheric effects on Martian ejecta emplacement (1979)
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    Publication Date: 2019-06-27
    Description: The paper presents analytical descriptions of crater growth and numerical calculations of aerodynamic drag to evaluate the possible effects of drag on impact crater ejecta emplacement on Mars. The critical particle size below which ejecta deposition is restricted in range increases with crater size; models of ejecta trajectories in the current Martian atmosphere under hydrostatic equilibrium reveal critical particle diameters ranging from 0.4 to 20 cm, noting that ejecta approaching the critical particle size may impact with crater radius of the excavation crater rim. Ejecta larger than the critical particle size are undecelerated and form secondary impact craters modified by the later arriving decelerated ejecta cloud; thus, ejecta emplacement will be multiphased, but the process depends on the ejecta size distribution.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Journal of Geophysical Research; 84; Dec. 10
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  • 199
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    Serenitatis multi-ringed basin - Regional geology and basin ring interpretation (1979)
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    Publication Date: 2019-06-27
    Description: New topographic data allow a reassessment of the ring structure and distribution of facies of the Serenitatis basin (SB) and correlation with the younger and essentially same-size Orientale basin. Three major rings of the main (southern) SB are mapped: the Linne ring, outlined by mare ridges, average diameter 420 km; the Haemus ring, outlined by basin-facing scarps and massifs with crenulated borders, 610 km; and the Vitruvius ring, outlined by basin-facing linear scarps and massifs, 880 km. The second ring is interpreted as the rim of the transient cavity, while Serenitatis ejecta should be present in significant amounts at the junction of the Serenitatis and Imbrium third rings. The new reconstruction indicates that portions of the SB are better preserved than previously thought, consistent with recent stratigraphic and sample studies that suggest an age (as young as 3.87 plus or minus 0.04 b.y.) for SB which is older than, but close to, the time of formation of the Imbrium basin.
    Keywords: LUNAR AND PLANETARY EXPLORATION
    Type: Moon and the Planets vol. 21; Dec. 197
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  • 200
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    Combining paleointensity methods - A dual-valued determination on lunar sample 10017,135 (1979)
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    Publication Date: 2019-06-27
    Description: A single-heating procedure for the determination of two partially independent values of paleofield intensity for one sample is presented. The procedure combines data for Shaw-type and 'ARM-method' determinations furnishing the ratio thermoremanent magnetization (TRM) to ARM acquisition efficiency corrected for physicochemical alteration to the magnetic carriers. Applicability of the Shaw-method to Fe-bearing samples is demonstrated by simulated paleointensity determinations on synthetic samples containing multidomain grains. The combined Shaw-ARM procedure was applied to a linear basalt sample, but the Thellier-Thellier method could not provide a meaningful determination of the neighboring chip. These conflicting findings may be explained by multiple step-wise heatings causing more damage to carriers than a single heating procedure, and by the natural remanent magnetization in this lunar basalt not being a simple TRM.
    Keywords: LUNAR AND PLANETARY EXPLORATION
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