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9.0

Jul 26, 2019
07/19

by
Gumowski, Igor

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vi, 329 p. : 24 cm. --

Topic: Nonlinear oscillations

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227

Jun 27, 2010
06/10

by
Marko, W

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Moving long cylindrical model for aerobraking tests at high speed in drop wire facility

Topics: LAPLACE EQUATION, MATHEMATICAL MODELS, TIDES, ANTISYMMETRY, HARMONIC FUNCTIONS, OSCILLATIONS, WAVE...

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348

Jun 21, 2010
06/10

by
Grimshaw, E. R.; Lohnes, R. A.; Matteo, D. N

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Mechanical properties of stabilization booms for gravity gradient studies on Applications Technology Satellites

Topics: ACTUATORS, ELECTRICAL PROPERTIES, MECHANICAL ENGINEERING, SPACECRAFT COMPONENTS, AEROSPACE SYSTEMS,...

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300

May 22, 2011
05/11

by
Caledonia, George E.; Krech, Robert H.; Oakes, David B

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A pulsed fast oxygen atom source has been used extensively over the last 7 years to investigate the effects of ambient oxygen atoms impacting materials placed in low Earth orbit. In this period, we irradiated well over 2000 material samples with 8 km/s oxygen atoms generated in our source. Typical irradiance level is 3 x 10(exp 20) O atoms/sq cm although some materials have been irradiated to fluence levels as high as 6 x 10(exp 21) O atoms/sq cm. The operating principles and characteristics of...

Topics: DISPLAY DEVICES, ELECTROMAGNETIC PULSES, EXCITATION, OSCILLATIONS, PULSED LASERS, RADIATION...

For Courant numbers larger than one and cell Reynolds numbers larger than two, oscillations and in some cases instabilities are typically found with implicit numerical solutions of the fluid dynamics equations. This behavior has sometimes been associated with the loss of diagonal dominance of the coefficient matrix. It is shown that these problems can be related to the choice of the spatial differences, with the resulting instability related to aliasing or nonlinear interaction. Appropriate...

Topics: NASA Technical Reports Server (NTRS), APPLICATIONS OF MATHEMATICS, FLUID DYNAMICS, SMOOTHING,...

The time dependent behavior of a plasma which surrounds a highly biased conducting sphere is considered. This plasma is treated as either a cold two component fluid or as a warm plasma whose time development can be found by solving the Vlasov equation. Both models demonstrate oscillatory behavior, but the electric fields predicted by the models are quantitatively quite different in regions close to the surface of the sphere and very similar otherwise. A broadening of the electron distribution...

Topics: NASA Technical Reports Server (NTRS), COLD PLASMAS, ELECTRIC FIELDS, MATHEMATICAL MODELS, PLASMA...

The quasi-biennial oscillations (QBO) in ozone and temperature vertical distributions are studied on the basis of ozonesonde data of 21 stations. Maximum QBO amplitudes in ozone are noted in the 16-20 kn layer over Resolute (75N), Aspendale (38S) and in the northern mid-latitude band, but in the 20-24 km layer in the northern subtropical band. In the upper layers the QBO effect is less evident. In the tropospheric layer it is difficult to note the QBO-related effect in all the groups of the...

Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC COMPOSITION, ATMOSPHERIC TEMPERATURE,...

Method and apparatus for obtaining dynamic calibrations of pressure transducers. A calibration head (15), a flexible tubing (23) and a bellows (20) enclose a volume of air at atmospheric pressure with a transducer (11) to be calibrated subject to the pressure inside the volume. All of the other apparatus in the drawing apply oscillations to bellows (20) causing the volume to change thereby applying oscillating pressures to transducer (11) whereby transducer (11) can be calibrated.

Topics: NASA Technical Reports Server (NTRS), CALIBRATING, DYNAMIC PRESSURE, OSCILLATIONS, PRESSURE...

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional,...

Topics: NASA Technical Reports Server (NTRS), ADAPTIVE FILTERS, AUTOMATIC FLIGHT CONTROL, CONTROL...

Theoretical model and data analysis of DE-2 observations for determining the correlation between the neutral wave activity and plasma irregularities have been presented. The relationships between the observed structure of the sources, precipitation and joule heating, and the fluctuations in neutral and plasma parameters are obtained by analyzing two measurements of neutral atmospheric wave activity and plasma irregularities by DE-2 during perigee passes at an altitude on the order of 300 to 350...

Topics: NASA Technical Reports Server (NTRS), GRAVITY WAVES, NONLINEARITY, OHMIC DISSIPATION, PERTURBATION,...

Bifurcation theory is used to analyze the nonlinear dynamic stability characteristics of an aircraft subject to single-degree-of-freedom. The requisite moment of the aerodynamic forces in the equations of motion is shown to be representable in a form equivalent to the response to finite amplitude oscillations. It is shown how this information can be deduced from the case of infinitesimal-amplitude oscillations. The bifurcation theory analysis reveals that when the bifurcation parameter is...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC STABILITY, AIRFOILS, BRANCHING (MATHEMATICS),...

Surface reactions involving O atoms are likely to be highly exoergic, with different consequences if energy is channeled mostly to product molecules or surface modes. Thus the surface may become a source of excited species which can react elsewhere, or a sink for localized heat deposition which may disrupt the surface. The vibrational energy distribution of the product molecule contains strong clues about the flow of released energy. Two instructive examples of energy partitioning at surfaces...

Topics: NASA Technical Reports Server (NTRS), OXIDATION, OXYGEN ATOMS, REACTION KINETICS, SURFACE...

An explicit-implicit and an implicit two-dimensional Navier-Stokes code along with various grid generation capabilities were developed. A series of classical benckmark cases were simulated using these codes.

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC INTERFERENCE, BOUNDARY LAYER SEPARATION,...

From published research it is known that a quasi-periodic 14 month atmospheric pressure oscillation of a few tenths of a millibar exists in the region of the North and Baltic Seas. At some time in the cycle the associated wind stress has a westerly component that drives a circulation in the North Sea. The results of a dynamical model and comparisons with several North Sea residual circulation studies show that a large sea level gradient results along the Dutch coast. It is this feature that has...

Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC PRESSURE, BALTIC SEA, NETHERLANDS, NORTH SEA,...

The flight of Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 allowed the collection of time sequences of diffraction limited (0.5 arc sec) granulation images with excellent pointing (0.003 arc sec) and completely free of the distortion that plagues groundbased images. The p-mode oscillations are clearly seen in the data. Using Fourier transforms in the temporal and spatial domain, it was shown that the p-modes dominate the autocorrelation lifetime in magnetic regions. When these...

Topics: NASA Technical Reports Server (NTRS), SOLAR ATMOSPHERE, SOLAR GRANULATION, SOLAR MAGNETIC FIELD,...

Experimental and computational tests were performed on a VR-12 airfoil to determine if the dynamic-stall behavior that normally accompanies high-angle pitch oscillations could be modified by segmenting the forward portion of the airfoil and extending it ahead of the main element. In the extended position the configuration would appear as an airfoil with a leading-edge slat, and in the retracted position it would appear as a conventional VR-12 airfoil. The calculations were obtained from a...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC STALLING, AIRFOIL OSCILLATIONS, AIRFOILS, ANGLE...

Stirling engine heat exchangers are shell-and-tube type with oscillatory flow (zero-mean velocity) for the inner fluid. This heat transfer process involves laminar-transition turbulent flow motions under oscillatory flow conditions. A low Reynolds number kappa-epsilon model, (Lam-Bremhorst form), was utilized in the present study to simulate fluid flow and heat transfer in a circular tube. An empirical transition model was used to activate the low Reynolds number k-e model at the appropriate...

Topics: NASA Technical Reports Server (NTRS), CIRCULAR TUBES, FLUID FLOW, HEAT FLUX, HEAT TRANSFER,...

Data obtained in the last 8 years of solar differential Doppler observations at Stanford were considered. The four best time series of data were examined in detail. The sources of error in the data were investigated and removed where possible. In particular, the contribution resulting from transparency variations in the sky was examined. Detection method applicable to data with low signal to noise ratio and low filling factor were developed and utilized for the investigation of global solar...

Topics: NASA Technical Reports Server (NTRS), DOPPLER EFFECT, ERROR ANALYSIS, IMAGE PROCESSING,...

Wind tunnel experiments were performed on a 70 deg sweep delta wing to determine the effect of a sinusoidal pitching motion on the pressure field on the suction side of the wing. Twelve pressure taps were placed from 35 to 90 percent of the chord, at 60 percent of the local semi-span. Pressure coefficients were measured as a function of Reynolds number and pitch rate. The pressure coefficient was seen to vary at approximately the same frequency as the pitching frequency. The relative pressure...

Topics: NASA Technical Reports Server (NTRS), DELTA WINGS, OSCILLATIONS, PRESSURE DISTRIBUTION, VORTEX...

A new procedure closely linking dissociation and exchange reactions in air to the vibrational levels of the diatomic molecules has been implemented in both one- and two-dimensional versions of Direct Simulation Monte Carlo (DSMC) programs. The previous modeling of chemical reactions with DSMC was based on the continuum reaction rates for the various possible reactions. The new method is more closely related to the actual physics of dissociation and is more appropriate to the particle nature of...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC HEATING, COMPUTERIZED SIMULATION, DIATOMIC...

We discuss dynamical systems that produce an oscillation without an external time dependent source. Numerical results are presented for nonlinear oscillators in the Em1h's atmosphere, foremost the quasi-biennial oscillation (QBOl. These fluid dynamical oscillators, like the solar dynamo, have in common that one of the variables in a governing equation is strongly nonlinear and that the nonlinearity, to first order, has particular form. of 3rd or odd power. It is shown that this form of...

Topics: NASA Technical Reports Server (NTRS), NONLINEARITY, OSCILLATIONS, OSCILLATORS, ATMOSPHERIC PHYSICS,...

This investigation was undertaken to determine the effect of varying the sampling period on the dynamic response of the sampled-data Large Space Telescope (LST) system. A range of sampling periods was recommended based on the criterion that self-sustained oscillations are to be avoided in the LST system. The step responses of the LST system were then investigated when various sampling periods are used. For small sampling periods, the dynamic behavior of the sampled-data system is very similar...

Topics: NASA Technical Reports Server (NTRS), CONTROL THEORY, DYNAMIC RESPONSE, HUBBLE SPACE TELESCOPE,...

Doppler velocity images obtained with the GONG prototype instrument were analyzed to measure the nearly steady photospheric flows. The data consists of 88 images each of velocity, intensity, and modulation obtained at 20:00 UT on 88 days from July 1992 to February 1994. Each velocity image was temporally filtered to remove the p-mode oscillations, masked to exclude active regions, and then analyzed using spherical harmonics and orthogonal functions as described by Hathaway (1992). The spectral...

Topics: NASA Technical Reports Server (NTRS), FLOW MEASUREMENT, FLOW VISUALIZATION, IMAGING TECHNIQUES,...

A pattern of variability in precipitation and 1000mb zonal winds for the tropical Indian Ocean during, 1979 to 1999 (AtmIO mode) is described using EOFs. The AtmIO mode consists of a cross-equatorial gradient of precipitation anomalies and equatorial wind anomalies of alternating signs on the Equator. The positive phase is defined as enhanced precipitation to the In "n south of the equator, suppressed precipitation to the north, and anomalous westerlies centered on the island of Sumatra....

Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, VARIABILITY, PRECIPITATION...

In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain...

Topics: NASA Technical Reports Server (NTRS), ADAPTIVE CONTROL, ROBUSTNESS (MATHEMATICS), MODEL REFERENCE...

The research work deals with the torsional vibration of a drill string in a vertical cylindrical cavity of a bore-hole with liquid medium. The mechanical interaction models of the drill string with viscous liquid are investigated, Also this paper describes the vibrations of the drill string bit with allowance made for viscous friction, the nonlinear deferential equation with partial derivatives is used. The oscillation scheme of torsional auto-vibration of homogeneous drill string in the form...

Topics: Vertical Bore-Holes, Auto-Vibration, Stationary Oscillations & Rotational Motions Dynamic...

The dynamical behavior of spacecraft propellant affected by the asymmetric combined gravity gradient and jitter accelerations, in particular the effect of surface tension on partially-filled rotating fluids applicable to a full-scale Gravity Probe-B Spacecraft dewar tank has been investigated. Three different cases of orbital accelerations: (1) gravity gradient-dominated, (2) equally weighted between gravity gradient and jitter, and (3) gravity jitter-dominated accelerations are studied. The...

Topics: NASA Technical Reports Server (NTRS), ANGULAR MOMENTUM, DYNAMIC CHARACTERISTICS, GRAVITATIONAL...

A review of solar constant determinations and measurements of its spectral distribution is presented. For the period from 1966 to 1980 a mean value of 1367 Wm-2 was determined. Within the corresponding uncertainty, no significant change of both the integral value and the spectral distribution can be detected. However, short term solar variations and their spectral dependence were deduced from measurements during four hours on June 20, 1980 from 34 km altitude with amplitudes of + or - 500 ppm...

Topics: NASA Technical Reports Server (NTRS), PERIODIC VARIATIONS, SOLAR CONSTANT, SOLAR SPECTRA, SPECTRAL...

2
2.0

Jul 26, 2019
07/19

by
Urabe, Minoru, 1912-

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xi, 330 p. :

Topics: Nonlinear theories, Oscillations

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127

May 31, 2011
05/11

by
Gladstone, G. Randal

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This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the...

Topics: QUASI-BIENNIAL OSCILLATION, STRATOSPHERE, SOLAR ACTIVITY, TWO DIMENSIONAL MODELS, MESOSPHERE,...

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191

May 23, 2011
05/11

by
Jacobson, Nathan S.; Lee, Kang N.; Yoshio, Tetsu

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The interaction of molten salts of different Na2O activities and mullite is examined with furnace and burner tests. The more-acidic molten salts form small amounts of Al2O3; the more-basic molten salts form various Na2O-Al2O3-SiO2 compounds. The results are interpreted using the Na2O-Al203-SiO2 ternary phase diagram, and some possible diffusion paths are discussed. The generally higher melting points of Na2O-Al2O3-SiO2 compounds lead to better behavior of mullite in molten salts, as compared to...

Topics: NAVIER-STOKES EQUATION, SUBSONIC FLOW, FINITE VOLUME METHOD, ANGLE OF ATTACK, FEEDBACK CONTROL,...

We investigate the dynamics of an arbitrary atomic system (n-level atoms or many n-level atoms) interacting with a resonant quantized mode of an em field. If the initial field state is a coherent state with a large photon number then the system dynamics possesses some general features, independently of the particular structure of the atomic system. Namely, trapping states, factorization of the wave function, collapses and revivals of the atomic energy oscillations are discussed.

Topics: NASA Technical Reports Server (NTRS), ATOMS, NUCLEAR ELECTRIC POWER GENERATION, PHOTONS, QUANTUM...

The bulk-flow analysis results for this contract are incorporated in the following publications: 'Fluid-Structure Interaction Forces at Pump-Impeller Shroud Surfaces for Axial Vibration Analysis'; 'Centrifugal Acceleration Modes for Incompressible Fluid in the Leakage Annulus Between a Shrouded Pump Impeller and Its Housing'; 'Influence of Impeller Shroud Forces on Pump Rotordynamics'; 'Pressure Oscillation in the Leakage Annulus Between a Shrouded Impeller and Its Housing Due to...

Topics: NASA Technical Reports Server (NTRS), CENTRIFUGAL PUMPS, COMPUTATIONAL FLUID DYNAMICS, DYNAMIC...

Zenith Tropospheric Delay (ZTD) due to water vapor derived from space geodetic techniques and numerical weather prediction simulated-reanalysis data exhibits non-linear and non-stationary properties akin to those in the crucial geophysical signals of interest to the research community. These time series, once decomposed into additive (and stochastic) components, have information about the long term global change (the trend) and other interpretable (quasi-) periodic components such as seasonal...

Topics: NASA Technical Reports Server (NTRS), ZENITH, TROPOSPHERE, GEOPHYSICS, OSCILLATIONS, EXTRACTION,...

We review the empirical constraints on accretion disk models of stellar-mass black holes based on recent multiwavelength observational results. In addition to time-averaged emission spectra, the time evolutions of the intensity and spectrum provide critical information about the structure, stability, and dynamics of the disk. Using the basic thermal Keplerian disk paradigm, we consider in particular generalizations of the standard optically thin disk models needed to accommodate the extremely...

Topics: NASA Technical Reports Server (NTRS), ACCRETION DISKS, BLACK HOLES (ASTRONOMY), EMISSION SPECTRA,...

Two papers on different aspects of the excitation and damping of solar oscillations were accepted for publication in the Astrophysical Journal. The first paper evaluates the rate at which turbulent convection feeds energy into individual p-modes. It is shown that stochastic excitation by turbulent convection provides a satisfactory fit to the product of the mode energies and linewidths. A somewhat surprising conclusion is that entropy fluctuations are about an order of magnitude more...

Topics: NASA Technical Reports Server (NTRS), ACOUSTIC SCATTERING, ATMOSPHERIC TURBULENCE, CONVECTIVE FLOW,...

The design of high efficiency supersonic inlets is a complex task involving the optimization of a number of performance parameters such as pressure recovery, spillage, drag, and exit distortion profile, over the flight Mach number range. Computational techniques must be capable of accurately simulating the physics of shock/boundary layer interactions, secondary corner flows, flow separation, and bleed if they are to be useful in the design. In particular, bleed and flow separation, play an...

Topics: NASA Technical Reports Server (NTRS), CORNER FLOW, ENGINE DESIGN, ENGINE INLETS, OBLIQUE SHOCK...

The behavior of unsteady aerodynamic loadings on airfoils oscillating in transonic flow has been investigated numerically with particular attention given to supercritical airfoil sections. A previously developed finite difference method, which is based on the full potential equation and which uses a quasi-conservative scheme for proper capture of a shock wave motion, was employed for the present study. The unsteady aerodynamic pressure and load distributions on several different airfoil...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, AIRFOILS, FINITE DIFFERENCE THEORY, TRANSONIC...

Considerable experimental evidence exists which shows that free stream disturbances (the ratio of root-mean-square pressure fluctuations to mean values) in conventional wind tunnels increase with increasing Mach number at low supersonic to moderate hypersonic speeds. In addition to local conditions, the free stream disturbance level influences transition behavior on simple test models. Based on this observation, existing noise transition data obtained in the same test facility were correlated...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER TRANSITION, FREE FLOW, PRESSURE OSCILLATIONS,...

During the past decade, direct measurements of ocean turbulent friction velocity and current velocity profiles have been conducted in polar regions using Autonomous Ocean Flux Buoys (AOFBs). Recent use of Synthetic Aperture Radar (SAR) imagery augmented by digital image processing techniques has proven to be an effective means of monitoring ice conditions. This study examines the relationship between ice-ocean drag coefficients and SAR-derived open water area, feature perimeter and ice ridge...

Topics: Arctic Ocean, Canada Basin, Beaufort Sea, transpolar drift sea ice, ice concentration, mixed layer,...

Typically, light interacts with matter via the electric field and interaction with weakly bound electrons. In a magnetic mirror, a patterned nanowire is fabricated over a metallic layer with a dielectric layer in between. Oscillation of the electrons in the nanowires in response to the magnetic field of incident photons causes a re-emission of photons and operation as a "magnetic mirror." By controlling the index of refraction in the dielectric layer using a local applied voltage, the...

Topics: NASA Technical Reports Server (NTRS), MAGNETIC MIRRORS, ELECTRIC FIELDS, DEFORMABLE MIRRORS,...

Aeroelastic tests require extensive cost and risk. An aeroelastic wind-tunnel experiment is an order of magnitude more expensive than a parallel experiment involving only aerodynamics. By complementing the wind-tunnel experiments with numerical simulations, the overall cost of the development of aircraft can be considerably reduced. In order to accurately compute aeroelastic phenomenon it is necessary to solve the unsteady Euler/Navier-Stokes equations simultaneously with the structural...

Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC CHARACTERISTICS, AERODYNAMICS, AEROELASTICITY,...

A modified approach to Childs' previous work on fluid-structure interaction forces in the leakage path between an impeller shroud and its housing is presented in this paper. Three governing equations consisting of continuity, path-momentum, and circumferential-momentum equations were developed to describe the leakage path inside a pump impeller. Radial displacement perturbations were used to solve for radial and circumferential force coefficients. In addition, impeller-discharge pressure...

Topics: NASA Technical Reports Server (NTRS), ACOUSTICS, COMPRESSIBILITY EFFECTS, COMPRESSIBLE FLUIDS,...

Feather seals (also called slot seals) typically found in turbine stators limit leakage from the platform into the core cavities and from the shroud to the case. They are of various geometric shapes, yet all are contoured to fit the aerodynamic shape of the stator and placed as close as thermomechanically reasonable the powerstream flow passage. Oscillations engendered in the compressor or combustor alter the steady leakage characteristics of these sealing elements and in some instances...

Topics: NASA Technical Reports Server (NTRS), FLOW STABILITY, COMPUTATIONAL FLUID DYNAMICS, SLOTS, SEALING,...

An unified approach for solving both compressible and incompressible flows was investigated in this study. The difference in CFD code development between incompressible and compressible flows is due to the mathematical characteristics. However, if one can modify the continuity equation for incompressible flows by introducing pseudocompressibility, the governing equations for incompressible flows would have the same mathematical characters as compressible flows. The application of a compressible...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY CONDITIONS, CIRCULAR CYLINDERS, COMPRESSIBILITY,...

Extensive research is being done toward the development of ultra-low-emissions combustors for aircraft gas turbine engines. However, these combustors have an increased susceptibility to thermoacoustic instabilities. This type of instability was recently observed in an advanced, low emissions combustor prototype installed in a NASA Glenn Research Center test stand. The instability produces pressure oscillations that grow with increasing fuel/air ratio, preventing full power operation. The...

Topics: NASA Technical Reports Server (NTRS), GAS TURBINE ENGINES, PRESSURE OSCILLATIONS, AIR FLOW,...

An outline and a brief introduction to some of the concepts and implications of Lyapunov stability theory are presented. Various aspects of the theory are illustrated by the inclusion of eight examples, including the Cartesian coordinate equations of the two-body problem, linear and nonlinear (Van der Pol's equation) oscillatory systems, and the linearized Kustaanheimo-Stiefel element equations for the unperturbed two-body problem.

Topics: NASA Technical Reports Server (NTRS), DIFFERENTIAL EQUATIONS, LIAPUNOV FUNCTIONS, NUMERICAL...

In order to enhance physical insight into the nature of thermal oscillations arising from a thin helium burning shell, the behavior in its phase plane of a simple two zone model which, however, contains all the relevant physics is analyzed. This simple model very naturally reproduces thermal flickers and is relatively insensitive to all but two parameters.

Topics: NASA Technical Reports Server (NTRS), B STARS, FLICKER, RADIATIVE TRANSFER, STELLAR MODELS,...

This paper covers the propulsion system component modeling and controls development of an integrated mixed compression inlet and turbojet engine that will be used for an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. Using previously created nonlinear component-level propulsion system models, a linear integrated propulsion system model and loop shaping control design have been developed. The design includes both inlet normal shock position control and jet engine rotor speed control...

Topics: NASA Technical Reports Server (NTRS), SUPERSONIC FLIGHT, CONTROL SYSTEMS DESIGN, SUPERSONIC...

Plasma kinetic theory is examined. Data cover nonlinear oscillations and plasma turbulence in uniform and nonuniform media.

Topics: NASA Technical Reports Server (NTRS), KINETIC THEORY, PLASMA DYNAMICS, PLASMA INTERACTIONS, PLASMA...