Some comments on the solution of linear equations
Computational methods of homogeneous ill- conditioned and singular simultaneous linear equations
Ramnath, B.↗
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Results for “computing methods”
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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Analysis of irrational transfer functions for distributed-parameter systems
Algorithmic and digital computer method for approximating irrational transfer functions by rational functions in control systems
Chen, C.-F.↗
An embodiment of some vertebrate command and control principles
Reticular formation of central nervous system in vertebrates described as behavior controlling circuit of interconnected modules, proposing hybrid computer method for operational scheme
Blum, J.↗
The impact of the computer on shell analysis
Thin walled shells structural vibration, buckling and stress analysis by computer methods, discussing shell theory and design
Stein, M.↗
Performance of a ten-stage electrostatic depressed collector for klystrons
Computational method for determining performance of ten stage electrostatic depressed collector for klystrons
Mihran, T. G.↗
On the Reduction of Proliferation of Finite Element Programs
Reduction of proliferation and maintainability of finite element method computer programs
Butler, T. G.↗
Computations with sparse matrices
Sparse matrices inverses and eigenvectors computation methods, giving bibliography
Tewarson, R. P.↗
COMAD - Application to future manned space vehicles
Computer methods for automatic diagnosis program applied to future manned space vehicles, discussing cost relationship to fault isolation techniques and component reliability
Garzia, R. F.↗
Identification of boiler inlet transfer functions and estimation of system parameters
An iterative computer method is described for identifying boiler transfer functions using frequency response data. An objective penalized performance measure and a nonlinear minimization technique are used to cause the locus of points generated by a transfer function to resemble the locus of points obtained from frequency response measurements. Different transfer functions can be tried until a satisfactory empirical transfer function of the system is found. To illustrate the method, some examples and some results from a study of a set of data consisting of measurements of the inlet impedance of a single tube forced flow boiler with inserts are given.
Miles, J. H.↗
Convection in the tanks of a rotating spacecraft
A general study of convection and mixing of a stratified fluid in a rotating container is described, with application to the special problem of fluid heating and convection in a spacecraft tank. The analysis was based on a set of approximate equations for the Navier-Stokes description of fluid convection with small density variations in a rotating system, including effects of body forces due to temperature stratification (caused by a heater) and arbitrary time-dependent rotation of the tank about a noncentral axis. An efficient numerical finite difference scheme and computational method are described for the convection of vorticity and energy in a two-dimensional tank. Special procedures were developed for analysis of the thermodynamic states resulting from the approximate flow equations derived for small density variations. Results of the numerical simulation are presented for studying the effectiveness of rotation maneuvers in mixing stratified oxygen in the tanks of an Apollo spacecraft. Significant effects of the rotation maneuvers are discussed, including the reduction of the potential for pressure collapse.
Source record↗
Numerical solution for propagation of coupled longitudinal and transverse waves normal to the applied magnetic field in a three-fluid medium.
The solution was obtained without approximating the dispersion relation. This was made possible by the use of a computer method for carrying out the extremely large number of algebraic manipulations involved. The three-fluid model employed accounts for the interaction of the electron, ion, and neutral species. The solution for the e-folding distance describes the damping characteristics of each wave mode. Each of the e-folding solutions corresponds to one of the phase velocity solutions.
Mcclendon, R. W.↗
Effects of circular geometry in simulation of convection in rotating spacecraft tanks
For computational simulation of the convection and mixing of stratified fluid in a rotating tank (such as used in Apollo flights) with time-dependent rotation, the Navier-Stokes convection problem was formulated for a circular tank configuration. The final equations results from a general approximate theory for combined forced and contained natural convection in a time-dependent rotating system. The equations are cast in terms of vorticity and stream function in a form convenient for computation, with a transformed coordinate system, and appropriate boundary conditions are derived. Accurate representations for the cryogenic supercritical oxygen thermodynamic properties are used in the computations, and an efficient numerical finite difference scheme and computational method are employed.
Martin, E. D.↗
An efficient algorithm for calculation of the Luenberger canonical form
An algorithm is suggested to obtain the Luenberger canonical form for multivariable systems. The method computes the canonical form directly without having to compute the transformation matrix. In addition, there is a large reduction in the number of calculations. The reduced computations along with Gaussian techniques lend to greater inherent accuracy and the ability to refine the solution with additional computations.
Jordan, D.↗
UK-5 Van Allen belt radiation exposure: A special study to determine the trapped particle intensities on the UK-5 satellite with spatial mapping of the ambient flux environment
Vehicle encountered electron and proton fluxes were calculated for a set of nominal UK-5 trajectories with new computational methods and new electron environment models. Temporal variations in the electron data were considered and partially accounted for. Field strength calculations were performed with an extrapolated model on the basis of linear secular variation predictions. Tabular maps for selected electron and proton energies were constructed as functions of latitude and longitude for specified altitudes. Orbital flux integration results are presented in graphical and tabular form; they are analyzed, explained, and discussed.
Stassinopoulos, E. G.↗
Predicted trapped particle radiation levels for Tiros-N
Vehicle encountered electron and proton fluxes were calculated for a set of nominal TIROS-N trajectories with new computational methods and new electron environment models. Temporal variations in the electron data were considered and partially accounted for. Estimates of energetic solar proton fluxes are given for the lifetime of the satellite at selected integral energies from 10 to 100 MeV. Field strength calculations were performed with an extrapolated model on the basis of linear secular variation predictions. Orbital flux integration results are presented in graphical and tabular form.
Stassinopoulos, E. G.↗
The radiation environment of OSO missions from 1974 to 1978
Trapped particle radiation levels on several OSO missions were calculated for nominal trajectories using improved computational methods and new electron environment models. Temporal variations of the electron fluxes were considered and partially accounted for. Magnetic field calculations were performed with a current field model and extrapolated to a later epoch with linear time terms. Orbital flux integration results, which are presented in graphical and tabular form, are analyzed, explained, and discussed.
Stassinopoulos, E. G.↗
Nonlinear analysis of a shock-loaded membrane.
Results from a computer method for analyzing the unsteady interaction of a fluid stream and a flat circular elastic membrane are presented. The loading on the membrane is assumed to be caused by the firing of a shock tube. The fluid pressures and velocities are determined from a scheme based on the numerical method of characteristics, and the membrane is analyzed using exact relations for membrane strain. The interactive solution is found to give peak stresses 40% lower than a solution which assumes a pressure invariant in space and time.
Madden, R.↗
One-dimensional transient waves in anisotropic plates.
The stresses and displacements induced in anisotropic plates by short-duration impact line forces are calculated in this paper. The anisotropy is related to the lay-up angles of the fibers of a laminated fiber composite plate. A modification of Mindlin's theory of crystal plates is used. The plate responses are calculated for various fiber lay-up angles and inclination of the line load to the axes of symmetry. Use is made of the computational method of the fast Fourier transform.
Moon, F. C.↗