Evidence for a helium flux in the lower thermosphere.
Helium flux in lower thermosphere, using diffusion theory for multicomponent gas mixture to determine equation for equilibrium distribution
Kasprzak, W. T.↗
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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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Symmetric gaseous diffusion coefficients.
Kinetic theory development of equations for multicomponent gaseous mixtures symmetric diffusion coefficients
Curtiss, C. F.↗
A study of the composition of the lower solar corona.
Lower solar corona composition changes due to pressure and thermal gradients calculated with multicomponent diffusion equations
Nakada, M. P.↗
Progress report on recent improvements in the analysis of surface wave observations.
Digital analysis of surface wave observations, discussing moving window, multiple filter, multicomponent recording, time variable filtration and cross correlation techniques
Asano, S.↗
Multifluid cosmologies
Coordinate system for synthesizing previous work on multifluid cosmologies, investigating noninteracting mixtures of multicomponent fluids
Hughston, L. P.↗
An evaluation of approximations used in the analysis of chemically reacting, stagnation- point boundary layers with wall injection
Chemically reacting stagnation point boundary layers with wall injection of gas, comparing multicomponent solution with binary approximation and chemical simplifications
Craig, R. A.↗
The effect of gas phase chemical reactions on heat transfer to a charring ablator
Gas phase chemical reactions effect on heat transfer to charring ablator, deriving numerical solution for multicomponent stagnation point flow
Gomez, A. V.↗
Time-dependent solutions of nonequilibrium airflow past a blunt body
Multicomponent nonequilibrium air flow past axisymmetric blunt body, calculating flow distribution at various attack angles with time dependent technique
Li, C. P.↗
Stagnation region heating of a phenolic-nylon ablator during return from planetary missions
The results of a stagnation-line analysis of the radiative heating of a phenolic-nylon ablator are reported. The analysis includes flowfield coupling with the ablator surface, equilibrium chemistry, multicomponent or binary diffusion and a coupled line and continuum radiation calculations. Users manual and operating instructions for the computer programs listed in the report are included.
Esch, D. D.↗
Ultraviolet photometry from the Orbiting Astronomical Observatory. II Interstellar extinction.
Evaluation of interstellar extinction curves over the region from 3600 to 1100 A for 17 stars. The observations were made by the two Wisconsin spectrometers on board the Orbiting Astronomical Observatory 2, with spectral resolutions of 10 and 20 A. The extinction curves generally show a pronounced maximum at 2175 plus or minus 25 A, a broad minimum in the region from 1800 to 1350 A, and finally a rapid rise to the far-ultraviolet. Large extinction variations from star to star are found, especially in the far-ultraviolet; however, with only two possible exceptions in this sample, the wavelength at the maximum of the extinction bump is essentially constant. These data are combined with visual and infrared observations to display the extinction behavior over a range in wavelength of about a factor of 20. The observations appear to require a multicomponent model of the interstellar dust.
Bless, R. C.↗
Dissipative effects in the expansion of the universe. I, II.
Consideration of dissipative processes in anisotropic homogeneous world models, showing that dissipation reduces the anisotropy. The viscosity approximation and its range of applicability is discussed. Examples are presented which have been calculated by the use of a simple approximation to the collision-time method, using the cross section appropriate to weak interaction neutrino scattering. It is found that such dissipation is quite effective except for one particular cosmological model which is axisymmetric and in which the entire expansion of the model is taken up by expansion along the axis. A detailed multicomponent model is developed for dissipative processes in Euclidean homogeneous cosmological models. These processes involve neutrinos which might have long mean free times in interaction with other constituents which are thermalized by electromagnetic interactions, and whose weak interactions produce thermal neutrinos.
Matzner, R. A.↗
Thermodynamic models in cosmochemical systems.
Generalized computer methods are developed for inferring details of the formation of cosmochemical systems. Compositions of ideal gas mixtures existing in equilibrium with multicomponent solid and liquid phases are calculated. A comparison of computed results with experimental data is made for the ternary system MgO-FeO-SiO2. While the ideal-solution approximation is shown to be inaccurate in dealing with the silicate melts, the stable phases and compositions can be accurately calculated in a system where there are only solids and gas. A model system containing the elements H, O, Si, Mg, S, C, Cl, and F is investigated over a range of compositions involving the gas and ten solid phases, to show the power of the technique in dealing with complex gas-solid equilibria. Systems close to cosmic composition are next considered, both with and without iron.
Griffiths, P. R.↗
Ion drift velocities in gaseous mixtures at arbitrary field strengths.
A momentum-transfer theory is used to obtain an expression for the drift velocity of an ion in a multicomponent gas mixture. This is combined with an approximate calculation of the partition of the ion energy in the mixture to yield a formula for the drift velocity in terms of the drift velocities in the pure component gases. Positive deviations from Blanc's law at high fields are predicted, of magnitudes that should be easily measured experimentally.
Mason, E. A.↗
Numerical studies of unsteady two dimensional subsonic flows using the ICE method
A numerical program was developed to compute transient compressible and incompressible laminar flows in two dimensions with multicomponent mixing and chemical reaction. The algorithm used the Los Alamos Scientific Laboratory ICE (Implicit Continuous-Fluid Eulerian) method as its base. The program can compute both high and low speed compressible flows. The numerical program incorporating the stabilization techniques was quite successful in treating both old and new problems. Detailed calculations of coaxial flow very close to the entry plane were possible. The program treated complex flows such as the formation and downstream growth of a recirculation cell. An implicit solution of the species equation predicted mixing and reaction rates which compared favorably with the literature.
Wieber, P. R.↗
Compositional characteristics of some Apollo 14 clastic materials.
Eighty-two subsamples of Apollo 14 materials have been analyzed by instrumental neutron activation analysis techniques for as many as 25 elements. In many cases, it was necessary to develop new procedures to allow analyses of small specimens. Compositional relationships among Apollo 14 materials indicate that there are small but systematic differences between regolith from the valley terrain and that from Cone Crater ejecta. Fragments from 1-2 mm size fractions of regolith samples may be divided into compositional classes, and the 'soil breccias' among them are very similar to valley soils. Multicomponent linear mixing models have been used as interpretive tools in dealing with data on regolith fractions and subsamples from breccia 14321. These mixing models show systematic compositional variations with inferred age for Apollo 14 clastic materials.
Lindstrom, M. M.↗
Ambipolar diffusion in the F1-region of the ionosphere.
Ambipolar diffusion is discussed for the case of a weakly-ionized, multicomponent plasma. Shortcomings of some of the previous formulations of this problem are pointed out. In particular, it is shown that the polarization electrostatic field acts to couple the motion of the various ions with the result that the diffusion velocity of each ion depends on the density gradients of all the ions.
Schunk, R. W.↗
Energy partitioning of gaseous ions in an electric field.
The partitioning of ion energy among thermal energy, drift energy, and random-field energy is studied by solution of the Boltzmann equation. An expansion in powers of the square of the electric field strength is obtained by Kihara's method. Numerical calculations for several ion-neutral force laws show that Wannier's constant mean-free-time model gives a reasonable first approximation. The formal extension to multicomponent mixtures is also given. The matrix elements obtained are tabulated, and can be used to study the field dependence of other moments of the ion-distribution function.
Hahn, H.-S.↗
Correlation and prediction of gaseous diffusion coefficients.
A new correlation method for binary gaseous diffusion coefficients from very low temperatures to 10,000 K is proposed based on an extended principle of corresponding states, and having greater range and accuracy than previous correlations. There are two correlation parameters that are related to other physical quantities and that are predictable in the absence of diffusion measurements. Quantum effects and composition dependence are included, but high-pressure effects are not. The results are directly applicable to multicomponent mixtures.
Marrero, T. R.↗