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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Analytical model of turbine-type flowmeter guides in the selection of valid extrapolation of available calibration data. An expression for flowmeter performance is developed to include the effects of fluid friction, bearing drag, and magnetic drag upon helical rotor design.
Latitudinal and vertical current components effects included in longitudinal current system supporting steady state distribution in geomagnetic anomaly
Rarefied hypersonic flow model for sharp flat plate in strong interaction regimes, discussing inviscid and viscous shock and merged layers subregimes
Dynamic model for ionospheric plasma with interhemispheric coupling
Semicircular canal ducts dynamic behavior, using mathematical model for wave transmission of elastic fluid-filled toroidal shell in rigid channel
Optimal design for noise attenuation by diesel engine exhaust mufflers using linearized acoustic models
A three-dimensional model for the annual and semiannual variations of the thermosphere is presented in which energy and diffusive mass transport associated with the global circulation are considered in a self-consistent form. It is shown that these processes play a major role in the thermosphere dynamics and account for a number of temperature and compositional phenomena.
Mathematical models of wave propagation in three-fluid plasma and numerical solutions to dispersion and propagation properties
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The effects of ionizing radiation emitted by quasi-stellar objects on intergalactic hydrogen are studied. The hydrogen is assumed to expand with the Universe, and the amount of ionizing radiation is estimated from observations of the QSO luminosity function. The discreteness of the radiation sources is taken into account in computing the thermal history of the medium. The amount of ionizing radiation is shown to be sufficient to allow the existence of a universal medium with a temperature less than 10,000 K and a density several times the smeared-out density of luminous matter in galaxies. Such a medium would escape detection with presently available techniques.
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Carbon compounds (CO and CO2) and methane are added to an existing computer program (Shimazaki and Laird, 1970, 1972), which calculates diurnal variations in density distributions of pure oxygen compounds, hydrogen compounds, and nitrogen compounds. For the present model calculations, the original program was modified to calculate the steady-state profiles for all constituents, and then these solutions were used as the initial condition for solving the time-dependent equations. The effects of chemical reactions and vertical eddy diffusion transport on the CH4 and CO concentrations above 40 km, where one-dimensional treatment may not be too inappropriate, are discussed. Some of the 15 constituents included in the computer program interact with CO and CH4 chemically, and CH4 is more sensitive to the eddy diffusion coefficient than any other constituent. Therefore it is easier to determine the most appropriate profile of the eddy diffusion coefficient by comparing the model profile with the observations for CH4.
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