Temperature-dependence of the diffusion constants of rigid, closed-cell foams
Temperature dependence of diffusion coefficient for carbon dioxide filled rigid polyurethane foam, using Fick law
Cuddihy, E. F.↗
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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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Heat transfer to solid-vapor mixtures of cryogens below their triple points flowing through heated tubes
Wall temperatures and heat transfer coefficients for solid-vapor mixtures of para hydrogen and nitrogen flowing in heated tube
Giarratano, P. J.↗
Inhomogeneities and iron diffusion in a Thailand tektite
Fe diffusion coefficients measured at various temperatures above 1150 C to calculate homogenization times of Thailand tektite source
Cooper, A. R.↗
Properties of a uranium plasma
Uranium plasma design and characteristics, measuring emission and absorption coefficients as function of temperature and pressure
Campbell, H. D.↗
Cell for measurement of basic electrical properties of amorphous and polycrystalline materials under pressure
Measuring instrument for amorphous and polycrystalline materials resistivity and Seebeck coefficient as function of temperature and pressure
Hadek, V.↗
Neutronics analysis of an open-cycle high-impulse gas core reactor concept
A procedure was developed to calculate the critical fuel mass, including the effects of propellant pressure, for coaxial-flow gas-core reactors operating at 196,600 newtons thrust and 4400 seconds specific impulse. Data were generated for a range of cavity diameter, reflector-moderator thickness, and quantity of structural material. Also presented are such core characteristics as upper limits on cavity pressure, spectral hardening in very-high-temperature hydrogen, and reactivity coefficients.
Whitmarsh, C. L., Jr.↗
The thermodynamic properties of nitrogen from 65 to 2000 K with pressures to 10,000 atmospheres
An equation of state is presented for liquid and gaseous nitrogen for temperatures from 65 degrees K to 2000 degrees K and pressures to 10,000 atmospheres. All the pressure-density-temperature data available from published literature have been corrected and applied to bring experimental temperatures into accord with the International Practical Temperature Scale of 1968. The coefficients of the equation of state were determined by a weighted least squares fit to selected published pressure-density-temperature data. The methods of weighting the various data for simultaneous fitting are presented and discussed.
Jacobsen, R. T.↗
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.↗
High temperature chemical kinetic study of the H2-CO-CO2-NO reaction system
An experimental study of the kinetics of the H2-CO-CO2-NO reaction system was made behind incident shock waves at temperatures of 2460 and 2950 K. The overall rate of the reaction was measured by monitoring radiation from the CO + O yields CO2 + h upoilon reaction. Correlation of these data with a detailed reaction mechanism showed that the high-temperature rate of the reaction N + OH yields NO + H can be described by the low-temperature (320 K) rate coefficient. Catalytic dissociation of molecular hydrogen was an important reaction under the tests conditions.
Jachimowski, C. J.↗
The distribution of ammonia and its photochemical products on Jupiter
Altitude profiles of ammonia and its photochemical products are generated in the light of measurements of the Jovian temperature structure, eddy transport coefficient, improved chemical scheme, and rate constants. Realistic limits are placed on the concentration of hydrazine which may participate in the recycling of ammonia on Jupiter. The maximum hydrazine-ice production rate is calculated to be about 1.3 mg/sq m per Jovian day. The distribution of nitrogen gas is presented with and without supersaturation of hydrazine. The nitrogen mixing ratio near the ammonia cloud top is estimated to be in the range between 10 to the -9th and 10 to the -11th power. An appreciable latitudinal variation in the ammonia concentration is expected.
Atreya, S. K.↗
Tabulation and summary of thermodynamic effects data for developed cavitation on ogive-nosed bodies
Thermodynamic effects data for developed cavitation on zero and quarter caliber ogives in Freon 113 and water are tabulated and summarized. These data include temperature depression (delta T), flow coefficient (C sub Q), and various geometrical characteristics of the cavity. For the delta T tests, the free-stream temperature varied from 35 C to 95 C in Freon 113 and from 60 C to 125 C in water for a velocity range of 19.5 m/sec to 36.6 m/sec. Two correlations of the delta T data by the entrainment method are presented. These correlations involve different combinations of the Nusselt, Reynolds, Froude, Weber, and Peclet numbers and dimensionless cavity length.
Holl, J. W.↗
Solar sailing - The concept made realistic
The practicability of using solar sails as a means of spacecraft propulsion is discussed with reference to a Haley's comet rendezvous mission in 1981. Two types of sails are examined: square and heliogyro. Because of ease of deployment (release into space from a space shuttle, and unfolding of the blades through solar radiation pressure) the latter is preferred. Structural and mission parameters are given for the heliogyro configuration, with attention to operational temperature limits and material coefficients. A cranking orbit is described, where a sail-powered spacecraft flies first toward the sun, and then away from it in order to achieve rendezvous with a comet. Other missions using solar sails, including a back-up mission to Encke's comet in 1983, are also discussed.
Friedman, L.↗
Optical absorption and radiative heat transport in olivine at high temperature
Results are presented of measurements of the optical absorption spectra (300-8000 nm) of olivine as a function of temperature (300-1700 K) under conditions of controlled and known oxygen fugacity within the stability field of the samples. The absorption spectra are used to calculate the temperature-dependent radiative transfer coefficient of olivine and to numerically study the accuracy of the method. The present absorption measurements in olivine under oxidizing conditions known to be within the olivine stability field indicate that the effective radiative conductivity K(R) is lower than that obtained in previous studies under different experimental conditions. The lower value of K(R) makes it more likely that some of the earth's internal heat is removed by convection and less likely that thermal models involving conduction and radiation alone will satisfactorily explain thermal conditions in the earth's mantle.
Shankland, T. J.↗
On the application of nonlinear load elements to thermal analyses using the NASTRAN thermal analyzer
The nonlinear load elements in thermal analysis are used to simulate an undocumented nonlinear thermal boundary condition. The treatment of the nonlinearity arising from the temperature-dependent convective film coefficients is shown in detail. As an illustration, emphasis is placed on the modeling techniques and their interrelationships with the solution accuracy as affected by a specific integration algorithm of the transient thermal analysis used in the NASTRAN Thermal Analyzer. Briefly shown is the underlying theory on which the maneuvering of terms pertinent to the modeling depends. This demonstration provides some insight into the intricacies of the method that would be general to all applications. A recommendation is also made to modify a nonlinear load element that will enhance the solution capability and broaden the scope of application.
Lee, H. P.↗
On the role of vibrational excitation in dissociative recombination
An improved physical model of dissociative recombination is presented and applied to experimental data on the temperature dependence of rate coefficients for the rare-gas and atmospheric-gas ions. It is shown that in the charge neutralisation of the rare-gas dimer ions, autoionisation plays an important role (at least in comparison with the atmospheric-gas ions) and contributes to the fast fall-off in the rate coefficient with vibrational excitation observed in shock tube studies. Numerical estimates of the observed fall-off in rate coefficient with increasing vibrational excitation are also presented.
Cunningham, A. J.↗
Voyager U.V. spectrometer observations of He 584 A dayglow at Jupiter
The intensity of Jupiter's He 584 A airglow has been measured by the Voyager UV spectrometers. The disk-averaged brightness is about 4 Rs and limb darkening is present. The intensity probably varies with longitude, the variation being out of phase with the H Lyman-alpha intensity bulge. Modelling of resonance scattering of the solar He 584 A line by Jupiter's atmosphere has shown that the hydrogen and helium emissions can be explained about equally well by at least two self-consistent scenarios involving the structure (temperature and eddy diffusion coefficient) and excitation of the atmosphere. All evidence points to a dramatic change of conditions in the Jovian atmosphere in the time between Pioneer and Voyager encounters.
Mcconnell, J. C.↗
Space Shuttle laminar heating with finite-rate catalytic recombination
Temperature-dependent catalytic recombination coefficients are used to calculate the heat flux to the Space Shuttle Orbiter. With variable entropy boundary-layer edge properties obtained from a reacting inviscid flow-field calculation, the reacting boundary-layer equations are solved along the forward 50 percent of the windward centerline using the boundary-layer integral matrix procedure. The results are compared with fully catalytic and noncatalytic reacting solutions, with equilibrium solutions, and with the Orbiter-design heating rates. The fully catalytic heat fluxes are about equal to the equilibrium predictions; whereas, the finite catalytic results are about 12 to 27 percent lower than the fully catalytic results (approaching the noncatalytic results downstream) and as much as 30 to 50 percent lower than design predictions away from the nose area.
Scott, C. D.↗
Finite element analyses of plane thermal entry-length flows
It is pointed out that the design of actively cooled engine and airframe structures for hypersonic flight requires strong interaction between fluid, thermal, and structural analyses. Research programs are being conducted to develop an integrated thermal-structural analysis capability based upon the finite element method. In connection with these programs, a finite element engineering approach has been developed based upon a number of assumptions customarily used in practical heat transfer analysis. An evaluation is conducted of the finite element engineering approach for entry-length flows. The evaluation makes use of an analysis of plane thermal entry-length flows by a finite element approach utilizing mean fluid temperatures with a convection coefficient. Another analysis is based on a finite element continuum approach, taking into account the rigorous momentum, mass, and energy equations of viscous, incompressible flow. The engineering approach was found to give excellent agreement with the rigorous continuum approach for Peclet number values not less than 100.
Thornton, E. A.↗