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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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General potential function in triaxially ellipsoidal coordinates for Laplace equation, examining near earth satellites and Vinti potential
Creep rupture data analysis model based on minimum commitment station function approach, generalizing hypothesized time temperature stress relation
Scans of lambda Lep, eta UMa, xi Dra, epsilon Dor, alpha Leo, phi Dra, upsilon Dra, beta Aur, alpha Pic and alpha Dor have been obtained with scanner OAO-2 over the range 1800-3600 A. These scans have been reduced to tracings of F sub lambda in the 20 A pass band vs. wavelength using a wavelength conversion scale and a relative spectral sensitivity function. The general trend of the relative flux plots compares well with the continua predicted by simple model atmospheres.
A general Hamiltonian function for a rotating moon in the field of the earth is expanded in terms of parameters orienting the spin angular momentum relative to the principal axes of the moon and relative to coordinate axes fixed in the orbit plane. The effects of elastic distortion are included as modifications of the moment of inertia tensor, where the magnitude of the distortion is parameterized by the Love number k sub 2.
The detection efficiencies of cylindrical detectors for various gamma ray photon angular distributions were studied in the energy range from .10 Mev to 15 Mev. These studies indicate that simple detector systems on small satellites can be used to measure flux anisotropy of cosmic gamma rays and the angular distribution of albedo gamma rays produced in planetary atmospheres. The results indicate that flat cylindrical detectors are most suitable for measuring flux anisotropy because of their angular response function. A general method for calculating detection efficiencies for such detectors is presented.
Evaluation of the photometric Mars observations performed during the exceptionally favorable opposition of this planet in 1971. The techniques employed included conventional photography, multichannel spot photometry, dual channel area scanning, and image digitizing. Among the results obtained, there are indications that the Minnaert function is generally valid for the bright areas of Mars.
It is important to define and evaluate measures which incorporate most, if not all, of the quantities affecting the overall system reliability. For the simple types of block codes normally employed in space communication systems, the complexity of the encoder and decoder is of little consequence, since the use of integrated circuit technology allows the construction of the basic components in an inexpensive fashion. The complexity is essentially independent of the particular code-decoder used. The processing speed is generally a function of the type of logic used and the technology in the construction of the integrated circuits.
Double scattering corrections for aureole radiances are calculated by adding the effects of two successive single scatterings. Atmospheric absorption, polarization, and variation of refractive index with altitude are ignored. Corrections due to spherical atmosphere were taken into account by the use of a generalized Chapman function. Realistic scattering phase functions based upon the Lorenz-Mie theory and model altitude-size distribution are used. The model distribution is assumed to be representable in terms of two separable particulate components. It was found that for a moderately clear day, tau (0) is approximately equal to 0.5, and for forward scattering angles, the radiance, B sub 2, due to double scattering is less than 6 percent of that due to single scattering.
An analytical investigation of single-stage vehicles with multiple propulsion phases has been conducted with the phasing optimized to minimize a general cost function. Some results are presented for linearized sizing relationships which indicate that single-stage-to-orbit, dual-fuel rocket vehicles can have lower inert weight than similar single-fuel rocket vehicles and that the advantage of dual-fuel vehicles can be increased if a dual-fuel engine is developed. The results also indicate that the optimum split can vary considerably with the choice of cost function to be minimized.
This paper presents a technique for the partial-fraction expansion of functions which are ratios of polynomials with real coefficients. The expansion coefficients are determined by writing the polynomials as Taylor's series and obtaining the Laurent series expansion of the function. The general formula for the inverse Laplace transform is also derived.
The automatic picture transmission digital scan converter is used at ground stations to convert signals received from scanning radiometers to data compatible with ground equipment designed to receive signals from vidicons aboard operational meteorological satellites. Information necessary to understand the circuit theory, functional operation, general construction and calibration of the converter is provided. Brief and detailed descriptions of each of the individual circuits are included, accompanied by a schematic diagram contained at the end of each circuit description. Listings of integral parts and testing equipment required as well as an overall wiring diagram are included. This unit will enable the user to readily accept and process weather photographs from the operational meteorological satellites.
A random process is formed by the product of a local Gaussian process and a random amplitude process, and the sum of that product with an independent mean value process. The mathematical properties of the resulting process are developed, including the first and second order properties and the characteristic function of general order. An approximate method for the analysis of the response of linear dynamic systems to the process is developed. The transition properties of the process are also examined.
General physical, functional, and operational interface control requirements for instruments on the first AMPS payload are presented. Interface specifications are included to satisfy ground handling, prelaunch, launch, stowage, operation, and landing activities. Applicable supporting documentation to implement the information is also given.
The manual control behavior of the operator with various levels of manipulator system complexity was studied in order to determine the relationships among control system dynamics, certain base engineering variables, controller designs and system performance. Based on the data obtained, a set of general transfer functions were prepared to provide a mathematical model of the various levels of potential force feedback fidelity as a function of force backlash present in alternate engineering designs.
The theory of perturbations, giving the diatomic effective Hamiltonian, is used for calculating actual molecular wave functions and intensity factors involved in transitions between states arising from Hund's coupling cases a,b, intermediate a-b, and c tendency. The Herman and Wallis corrections are derived, without any knowledge of the analytical expressions of the wave functions, and generalized to transitions between electronic states with whatever symmetry and multiplicity. A general method for studying perturbed intensities is presented using primarily modern spectroscopic numerical approaches. The method is used in the study of the ScO optical emission spectrum.
A methodology is introduced for constructing numerical analogs of the partial differential equations of continuum mechanics. A general formulation is provided which permits classical finite element and many of the finite difference methods to be derived directly. The approach, termed the General Interpolants Method (GIM), can combined the best features of finite element and finite difference methods. A quasi-variational procedure is used to formulate the element equations, to introduce boundary conditions into the method and to provide a natural assembly sequence. A derivation is given in terms of general interpolation functions from this procedure. Example computations for transonic and supersonic flows in two and three dimensions are given to illustrate the utility of GIM. A three-dimensional nozzle-exhaust flow field is solved including interaction with the freestream and a coupled treatment of the shear layer. Potential applications of the GIM code to a variety of computational fluid dynamics problems is then discussed in terms of existing capability or by extension of the methodology.
Anharmonic models are used to describe the high temperatures and the electronic effects characteristic of shock wave phenomena and planetary interiors. It is found that a generalized Grueneisen function dependent on temperature and volume is necessary for the self-consistent application of the Mie-Grueneisen equation at the physical conditions encountered in shock wave phenomena or in the interior of planets. It is noted that at temperatures of a few thousand degrees Kelvin, by deriving the function in terms of anharmonic lattice dynamics, the difference between gamma and gamma(th) is of the same order of a magnitude as gamma. This leads to the conclusions that (1) gamma is not a function of temperature and (2) gamma?gamma(th) does not explain either the equation of state of planetary interiors or high-temperature shock wave phenomena.
In the present note we first give a simple proof of the Dainelli formulas for the force field generating a given family of orbits. We also show that the Szebehely partial differential equation for the potential can be derived from the Dainelli formulas if the energy integral is assumed. The Szebehely equation can be solved directly with the method of characteristics or indirectly with the Joukovsky formulas. Several examples are briefly described in the article. In particular we find some rather general potential functions corresponding to circular motion.