The significance of the wave picture in the the theory of diurnal tides within the thermosphere
Significance of wave generation in mathematical description of thermospheric diurnal tides
Mayr, H. G.↗
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Results for “wave generator”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Theoretical seismograms excited by a localized radial stress on the surface of a gravitating homogeneous mantle over a liquid core.
Seismic wave generation, propagation, dispersion and attenuation in gravitating sphere having homogeneous elastic mantle and liquid core, giving theoretical seismograms
Landisman, M.↗
Wind tunnel airstream oscillating apparatus Patent
Wind tunnel air flow modulating device and apparatus for selectively generating wave motion in wind tunnel airstream
Loftin, L. K., Jr.↗
High frequency electrostatic waves in the magnetosphere
HF electrostatic waves generation by electrons in magnetosphere
Fredricks, R. W.↗
The Alfven velocity in the magnetosphere and its relationship to ELF emissions
Magnetosphere Alfven velocity profile relation to ELF chorus and hiss, indicating unstable wave generation by cyclotron resonance
Burton, R. K.↗
Vibrational relaxation measurements of carbon monoxide in a shock-tube expansion wave
CO vibrational relaxation measurements in shock tube expansion wave generated in argon heat bath
Appleton, J. P.↗
Waveform simulator Patent
Sign wave generation simulator for variable amplitude, frequency, damping, and phase pulses for oscilloscope display
Malmberg, J. H.↗
A linearized solution to impulsive latent heat release in a dilute, isothermal atmosphere
One dimensional model for analytical solution to problem of impulsive heat release by chemically generated waves in dilute, isothermal atmosphere
Eberstein, I. J.↗
Electronic signal generators: A compilation
Electronic signal generator data based on solid state concepts were simplified or refined to meet requirements, such as reliability, simplicity, fail-safe characteristics, and the capability of withstanding environmental extremes. Pulse generators, high voltage pulse generators, oscillators, analog signal generators, square wave signal generators, and special function signal generators are described.
Source record↗
Atmospheric pressure, density, temperature and wind variations between 50 and 200 km
Data on atmospheric pressure, density, temperature and winds between 50 and 200 km were collected from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others. These data were analyzed by a daily difference method and results on the distribution statistics, magnitude, and spatial structure of the irregular atmospheric variations are presented. Time structures of the irregular variations were determined by the analysis of residuals from harmonic analysis of time series data. The observed height variations of irregular winds and densities are found to be in accord with a theoretical relation between these two quantities. The latitude variations (at 50 - 60 km height) show an increasing trend with latitude. A possible explanation of the unusually large irregular wind magnitudes of the White Sands MRN data is given in terms of mountain wave generation by the Sierra Nevada range about 1000 km west of White Sands. An analytical method is developed which, based on an analogy of the irregular motion field with axisymmetric turbulence, allows measured or model correlation or structure functions to be used to evaluate the effective frequency spectra of scalar and vector quantities of a spacecraft moving at any speed and at any trajectory elevation angle.
Justus, C. G.↗
An analysis of Pioneer 9 low-frequency wave observations near interplanetary discontinuities.
Observation of an unusually complex sector boundary on Feb. 2, 1969. Within a single seven-hour period the Pioneer 9 magnetometer and plasma probe detected a reverse shock, a slow shock, and a conventional fast shock. During this interval the electron gyrofrequency and the ion plasma frequency each varied by more than a factor of 10, and the low-frequency (broadband and 400-Hz) electric field wave levels were high and variable. It is shown that, near the discontinuities, enhanced 400-Hz wave levels were not generally associated with field gradients or current layers, but elevated 400-Hz wave levels were detected when the ion density fell within a fairly well-defined window. This suggests that modes related to ion sound waves were detected, and the observations are assessed in terms of various theories for interplanetary wave generation.
Scarf, F. L.↗
High frequency Hall current instability
The Hall current electrojet instability was studied to determine if it generates VLF hiss in the auroral zone of magnetic substorms. Using the kinetic equations with particle conserving Krook collision operator for electrons and ions, and Poisson's equation, it is shown that in the low frequency region, the range of frequency of unstable modes increases as the electron density increases, and that the high frequency component must be taken into account in calculations of turbulent saturation of the Hall current instability driven beyond threshold. It is concluded that Hall currents can generate waves in the VLF hiss frequency band which are related to local auroral electrojet activity.
Lee, K.↗
Possible explanation for nonthermal radio noise from binary stars.
Radio emission from the binary stars alpha-Sco, beta-Per, and beta-Lyr is interpreted as due to the mass exchange between the components. The electrons in the inflowing stream excite plasma waves near the surface of the receptor star, and these waves generate radio emission. Crude predictions of radio frequency, intensity, and timescales of variation seem compatible with current observations.
Jones, T. W.↗
Analysis of supersonic combustion flow fields with embedded subsonic regions
The viscous characteristic analysis for supersonic chemically reacting flows was extended to include provisions for analyzing embedded subsonic regions. The numerical method developed to analyze this mixed subsonic-supersonic flow fields is described. The boundary conditions are discussed related to the supersonic-subsonic and subsonic-supersonic transition, as well as a heuristic description of several other numerical schemes for analyzing this problem. An analysis of shock waves generated either by pressure mismatch between the injected fluid and surrounding flow or by chemical heat release is also described.
Dash, S.↗
The interior of the Moon
Questions of lunar bulk chemistry are being considered, giving attention to the depletion of the moon in iron and compounds more volatile than iron. Currently four seismic stations are operating on the moon to provide data for the study of the lunar interior. The travel times of seismic waves generated by artificial impacts have been used to determine the structure of the outer 150 km of the moon. New evidence fails to resolve the controversy whether the lunar interior is hot or cold. A schematic cross section of the moon is presented and problems concerning the origin of the moon are considered.
Anderson, D. L.↗
Intensity and energy spectrum of electrons accelerated in the earth's bow shock
Shock waves accelerate charged particles in the solar atmosphere, in interplanetary space and around the earth's magnetosphere. Acceleration of both electrons and protons occurs in the earth's bow-shock. The acceleration of protons up to 100 keV appears to be a steady state process and may even occur upstream from the bow shock due to waves generated by reflected solar wind protons. The electrons, on the other hand, are known to be accelerated in or near the shock. The intensity of these electrons ranges from about 100 to 2,000 per sr-sq cm-sec-keV at 14 keV. The energy spectrum is not a simple power low and is highly variable. If segments of the spectra are fitted to a power low, slopes ranging from -2 to -4.5 result over the energy range 0.5 to 100 keV.
Anderson, K. A.↗
An analysis of the strong zonal circulation within the stratosphere of Venus
A dynamic model is presented for the strong zonal circulation within the stratosphere of Venus which was observed by Mariner 10 and Venera. Rotational effects are neglected, a compressible and radiating atmosphere is considered, and diurnal radiative heating is shown to be negligible in the lower stratosphere (below 85 km). Analysis of the model indicates that propagating internal gravity waves generated by solar heating of the upper stratosphere may induce mean zonal velocities within the upper and lower stratosphere which would have a retrograde direction. The nonlinear equations of motion and energy are solved by an approximate analytical method to determine the magnitude of the zonal velocity, which is found to increase from zero at the tropopause to about 200 m/sec at the 85-km level. The calculated velocity near the UV cloud level compares favorably with the observed value of 100 m/sec.
Ramanathan, V.↗
Sound scattering by rigid oblate spheroids, with implication to pressure gradient microphones
The frequency limit below which sound scattering by a microphone body is sufficiently small to permit accurate pressure gradient measurements was determined. The sound pressure was measured at various points on the surface of a rigid oblate spheroid illuminated by spherical waves generated by a point source at a large distance from the spheroid, insuring an essentially plane sound field. The measurements were made with small pressure microphones flush mounted from the inside of the spheroid model. Numerical solutions were obtained for a variety of spheroid shapes, including that of the experimental model. Very good agreement was achieved between the experimental and theoretical results. It was found that scattering effects are insignificant if the ratio of the major circumference of the spheroid to the wavelength of the incident sound is less than about 0.7, this number being dependent upon the shape of the spheroid. This finding can be utilized in the design of pressure gradient microphones.
Maciulaitis, A.↗