Search NASA⌕ Search

SEARCH · Search NASA

Results for “60”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Energetic (above 60 eV) atmospheric photoelectrons

Data from low altitude plasma instrument (LAPI) on Dynamics Explorer 2 document a population of high-energy (up to 800 eV) atmospheric photoelectrons that has not been reported in the published literature. The source of these photoelectrons is postulated to be the soft X-ray portion of the whole sun spectrum. This conclusion is supported by sunrise-sunset characteristics that track those of the classical (below 60 eV) EUV-produced photoelectrons, and theoretical results from two models that incorporate the soft X-ray portion of the solar spectrum. The models include K-shell ionization effects and predict peaks in the photoelectron spectrum due to Auger electrons emitted from oxygen and nitrogen. The peak for nitrogen is observed as predicted, but the peak for oxygen is barely observable. Excellent quantitative agreement is achieved between theory and experiment by using reasonable adjustments to the few published soft X-ray spectra based on solar activity. The upflowing energetic photoelectrons provide a heretofore unknown source of electrons to the magnetosphere. They occur whenever and wherever the sun is up, that is, at all invariant latitudes. Their density is low, but they are steady and ubiquitous. If scattering and trapping occur on closed field lines, then photoelectrons could contribute as a significant particle source and thus represent a new facet of magnetosphere-ionosphere coupling.

Winningham, J. D.↗
NASA NTRS1990

Differences in the solar modulation of E greater than 60 MeV cosmic rays at earth and 18 AU during a complete 11-year cycle from 1977 to 1988

The cosmic ray intensities for E greater than 60 MeV particles at a constant radius of 18 AU using data from the IMP, Voyager and Pioneer spacecraft. These intensities are compared with the intensities at earth for a complete 11-year cycle from 1977 to 1988. It is found that the variations at 1 AU and 18 AU track very closely during the decreasing portion of the cycle from 1977 to 1982 but during the recovery the intensity at 18 AU increases much less than at earth with the result that in 1987 the intensity is only 82 percent of that at the previous minimum in 1977. These results imply that the integral radial gradient between 1 and 18 AU is constant in time from 1977 to 1982 but decreases from 1982 to 1988. Thus, the amplitude of the 11-year variation observed at a fixed energy is quite strongly radially dependent, with the amplitude becoming less at larger radii.

Lockwood, J. A.↗
NASA NTRS1989

Measurement of the cosmic ray iron spectrum above 60 GeV/n

A measurement of the spectral index of Galactic cosmic ray (GCR) iron has been performed using the High Energy Gas Cerenkov Spectrometer. The spectral index of GCR iron, in the energy range 60 to 200 GeV/n, has been determined to be 2.56 + or - 0.11. This result indicates that the source spectrum of GCR iron is similar to that of other primary GCR nuclei, as expected in the standard leaky box model.

Esposito, J. A.↗
NASA NTRS1990

The 60 micron to 20 centimeter infrared-to-radio ratio within spiral galaxies

A detailed comparison is presented of the distribution of 60 micron IR and 20 cm radio continuum emission within 25 galaxies, mostly disk spirals. Local maxima in the thermal IR and nonthermal radio emission are found to be spatially coincident on scales of less than about 0.4 kpc in the nearest sample galaxies. The IR-red disk in normal spirals appears to be characterized by a shorter scale length than that of the radio continuum disk, suggesting that the IR-to-radio ratio should decrease as a function of radius. A model that successfully accounts for the observations is introduced which is based on the assumptions of steady-state star formation activity within the disk on kpc scales and a tight coupling between the origins of the dust-heating radiation and the radio-emitting cosmic-ray electrons. The underlying source is described as an exponential disk. The results also suggest that a random walk process cannot by itself describe the temporal evolution of cosmic rays.

Bicay, M. D.↗
NASA NTRS1992

Vortex trapping on a 60 degree delta wing

An experiment was conducted to examine the vortex trapping concept on a 60 deg sweep delta wing at low angles of attack. Using tapered leading edge fences, stable vortices have been successfully trapped. The resulting increase in lift coefficient can be as high as 0.4, which amounts to a 6.5 deg shift in the lift coefficient curve of the delta wing. The corresponding increase in drag coefficient, however, is also significant.

Buchholz, Mark D.↗
NASA NTRS1993

Effects of radiobiological uncertainty on shield design for a 60-day lunar mission

Some consequences of uncertainties in radiobiological risk due to galactic cosmic ray exposure are analyzed to determine their effect on engineering designs for a first lunar outpost - a 60-day mission. Quantitative estimates of shield mass requirements as a function of a radiobiological uncertainty factor are given for a simplified vehicle structure. The additional shield mass required for compensation is calculated as a function of the uncertainty in galactic cosmic ray exposure, and this mass is found to be as large as a factor of 3 for a lunar transfer vehicle. The additional cost resulting from this mass is also calculated. These cost estimates are then used to exemplify the cost-effectiveness of research.

Wilson, John W.↗
NASA NTRS1993

Gravity wave and tidal structures between 60 and 140 km inferred from space shuttle reentry data

This study presents an analysis of density measurements made using high-resolution accelerometers aboard several space shuttles at altitudes from 60 to 140 km during reentry into the earth's atmosphere. The observed density fluctuations are interpreted in terms of gravity waves and tides and provide evidence of the importance of such motions well into the thermosphere. Height profiles of fractional density variance reveal that wave amplitudes increase at a rate consistent with observations at lower levels up to about 90 km. The rate of amplitude growth decreases at greater heights, however, and appears to cease above about 110 km. Wave amplitudes are nevertheless large at these heights and suggest that gravity waves may play an important role in forcing of the lower thermosphere.

Fritts, David C.↗
NASA NTRS1993

Installed F/A-18 inlet flow calculations at 60 deg angle-of-attack and 10 deg side slip

This paper presents the results of PARC3D numerical calculations on a 19.78 percent scale forebody/inlet model of the F/A-18 at a Mach number of 0.20, an angle-of-attack of 60 deg, and a side-slip angle of 10 deg. The main purpose of these calculations is to support an upcoming wind-tunnel test program in the prediction of engine inlet compressor face total pressure recovery and flow distortion. The GRIDGEN system was used to generate a grid which includes the inlet and lip, and other aircraft components which are considered to be important to inlet performance, such as the ramp/splitter plate, the diverter and slot, and the deflected leading edge flap. PARC3D shows complex flow patterns on the fuselage surfaces below the leading edge extensions, on the ramp/splitter plate, inlet lip, and inside the inlet. PARC3D tends to underpredict total pressure recovery and overpredict the flow distortion at the inlet compressor face.

Podleski, S. D.↗
NASA NTRS1954

Investigation at transonic speeds of the lateral-control and hinge-moment characteristics of a flap-type spoiler aileron on a 60 degree delta wing

This paper present results of an investigation of the lateral-control and hinge-moment characteristics of a 0.67 semispan flap-type spoiler aileron on a semispan thin 60 degree delta wing at transonic speeds by the reflection-plane technique. The spoiler-aileron had a constant chord of 10.29 percent mean aerodynamic chord and was hinged at the 81.9-percent-wing-root-chord station. Tests were made with the spoiler aileron slot open, partially closed, and closed. Incremental rolling-moment coefficients were obtained through a Mach number range of 0.62 to 1.08. Results indicated reasonably linear variations of rolling-moment and hinge-moment coefficients with spoiler projection except at spoiler projections of less than -2 percent mean aerodynamic chord and angles of attack greater than 12 degrees with results generally independent of slot geometry.

Wiley, Harleth G↗
NASA NTRS1954

A wind-tunnel investigation at high subsonic speeds of the lateral control characteristics of various plain spoiler configurations on a 3-percent-thick 60 degree delta wing

Results are presented of wind-tunnel investigations at Mach numbers of 0.60 to 0.94 and angles of attack of -2 degrees to about 24 degrees to determine the lateral control characteristics of spoilers with various wing chord-wise and spanwise locations and spoiler spans and deflections on thin 60 degree delta wing of NACA 65a003 airfoil section parallel to free stream.

Wiley, Harleth G↗
NASA NTRS1956

Tabulated Pressure Data for a Series of Controls on a 60 Degree Delta Wing at Mach Numbers of 1.61 and 2.01

An investigation has been made at Mach numbers of 1.61 and 2.01 and Reynolds numbers from 1.7 X 10 to 7.6 X 10 to determine the pressure distributions over a 60 deg. delta wing having 20 different control configurations. Measurements were made at angles of attack from O deg to 15 deg for control deflections from -30 deg to 30 deg. This report presents the complete tabulated pressure data for the range of test conditions.

Lord, Douglas R↗
NASA NTRS1994

Discriminating performance parameters for 50 amp-hour and 60 amp-hour nickel-cadmium plates and battery cells

This is a follow-up of studies of the NASA standard 50 AH cell presented at the NASA battery workshop each of the last two years. This is a dynamic study. Data trends continue to be developed and analyzed for their utility in judging NiCd performance. The trends and parameters presented here may bear relevance to many designs of conventional NiCd batteries, not just the 50 AH and 60 AH sizes.

Toft, Mark R.↗
NASA NTRS1994

Azimuthally averaged radial S(sub 100 microns)/S(sub 60 microns) dust color temperatures in spiral galaxies

The IRAS S(sub 100 micron)/S(sub 60 micron) dust color temperature profiles are presented for two nearby spiral galaxies M 101 and M 81. The radial dust temperature profiles provided an important constraint on the origin of the far-infrared luminosity. The observed dust temperature is compared with that expected for diffuse interstellar dust heated by the general interstellar radiation field within each galaxy. The implications for the contribution of cirrus to the far-infrared luminosity of M 101 and M 81 are discussed.

Devereux, Nick A.↗
NASA NTRS1994

Extended 60 micrometers emission from nearby Mira variables

The Infrared Astronomy Satellite (IRAS) has detected extended emission around a number of evolved stars. Individual IRAS scans of nearby Mira variables which showed emission from circumstellar dust and for which distance estimates were available were examined. Extended emission at 60 micrometers was detected for R Cas, o Cet, R Leo, U Ori, and possibly for R Hor. The Leung code for the calculation of radiative transfer in a circumstellar dust shell was used to calculate the emission from model dust shells composed of silicate grains. The output was convolved with the IRAS beam profile to determine whether steady mass loss could explain the observed extension. The observed extensions for o Cet, R Hor and U Ori could be due to steady mass loss, while the model calculations do not produce enough extension to explain the observations of R Cas and R Leo.

Bauer, Wendy Hagen↗
NASA NTRS1993

Aerodynamic tailoring of the Learjet Model 60 wing

The wing of the Learjet Model 60 was tailored for improved aerodynamic characteristics using the TRANAIR transonic full-potential computational fluid dynamics (CFD) code. A root leading edge glove and wing tip fairing were shaped to reduce shock strength, improve cruise drag and extend the buffet limit. The aerodynamic design was validated by wind tunnel test and flight test data.

Chandrasekharan, Reuben M.↗
NASA NTRS1995

Low-speed wind tunnel investigation of the stability and control characteristics of a series of flying wings with sweep angles of 60 deg

A wind tunnel investigation was conducted in the Langley 12-Foot Low-Speed Wind Tunnel to study the low-speed stability and control characteristics of a series of four flying wings over an extended range of angle of attack (-8 deg to 48 deg). Because of the current emphasis on reducing the radar cross section of new military aircraft, the planform of each wing was composed of lines swept at a relatively high angle of 60 deg, and all the trailing-edge lines were aligned with one of the two leading edges. Three arrow planforms with different aspect ratios and one diamond planform were tested. The models incorporated leading-edge flaps for improved pitching-moment characteristics and lateral stability and had three sets of trailing-edge flaps that were deflected differentially for roll control, symmetrically for pitch control, and in a split fashion for yaw control. Top bodies of three widths and twin vertical tails of various sizes and locations were also tested on each model. A large aerodynamic database was compiled that could be used to evaluate some of the trade-offs involved in the design of a configuration with a reduced radar cross section and good flight dynamic characteristics.

Moul, Thomas M.↗
NASA NTRS1995

KAO 60-micron imaging observations of galaxies with active star formation

We have carried out 60 micron imaging observations of a sample of nearby, far-infrared bright galaxies, using the Yerkes infrared camera aboard the KAO. A total of eleven galaxies have been observed, most of which are actively star-forming, barred spirals. In this contribution we present our first set of observations on four galaxies: NGC 4102, NGC 4536, NGC 5962, and NGC 6181.

Wang, Zhong↗