250
250
May 30, 2010
05/10
by
Aben, Kh. K
texts
eye 250
favorite 0
comment 0
Three-dimensional photoelastic models
Topics: PHOTOELASTICITY, THREE DIMENSIONAL MODELS, PHOTOELASTICITY
521
521
Jun 2, 2011
06/11
by
Martin, Preston B.; Leishman, J. Gordo
texts
eye 521
favorite 0
comment 0
This work examined the wake aerodynamics of a single helicopter rotor blade with several tip shapes operating on a hover test stand. Velocity field measurements were conducted using three-component laser Doppler velocimetry (LDV). The objective of these measurements was to document the vortex velocity profiles and then extract the core properties, such as the core radius, peak swirl velocity, and axial velocity. The measured test cases covered a wide range of wake-ages and several tip shapes,...
Topics: COMPUTATIONAL FLUID DYNAMICS, ALGORITHMS, THREE DIMENSIONAL MODELS, AIRFOILS, CARTESIAN COORDINATES
27
27
Oct 28, 2019
10/19
by
Prosise, Jeff
texts
eye 27
favorite 0
comment 0
xi, 182 pages : 27 cm
Topics: Computer graphics, COMPUTER GRAPHICS, Computergrafik, THREE DIMENSIONAL MODELS, IMAGE PROCESSING
611
611
May 31, 2011
05/11
by
Cornett, Robert H
texts
eye 611
favorite 0
comment 0
This report covers software and science support activities for the Laboratory for Astronomy & Solar Physics at NASA/Goddard Space Flight Center.
Topics: HELIOSPHERE, MAGNETOHYDRODYNAMICS, SOLAR PHYSICS, SOLAR CORONA, THREE DIMENSIONAL MODELS, SUN
182
182
May 23, 2011
05/11
by
Moses, Julianne I.; Allen, Mark; Gladstone, G. Randal
texts
eye 182
favorite 0
comment 0
We have modeled the photochemical evolution of the sulfur containing species that were observed in Jupiter's stratosphere after the Shoemaker Levy 9 (SL9) impacts. We find that most of the sulfur is converted to S8 in the first few days. Other important sulfur reservoirs are CS, whose abundance increases markedly with time, and possibly H2CS, HNCS, and NS, whose abundances depend on kinetic reaction rates that are unknown at the present. We discuss the temporal variation of the major sulfur...
Topics: HYPOTHESES, VORTICITY, ERRORS, DATA ACQUISITION, THREE DIMENSIONAL MODELS, MIXING LAYERS (FLUIDS)
334
334
May 27, 2011
05/11
by
Heatwole, Craig M.; Bernhard, Robert J.; Franchek, Matthew A
texts
eye 334
favorite 0
comment 0
A significant component of the interior noise of aircraft and automobiles is a result of turbulent boundary layer excitation of the vehicular structure. In this work, active robust feedback control of the noise due to this non-predictable excitation is investigated. Both an analytical model and experimental investigations are used to determine the characteristics of the flow induced structural sound radiation problem. The problem is shown to be broadband in nature with large system...
Topics: HALOCARBONS, HYDROLYSIS, DEGRADATION, THREE DIMENSIONAL MODELS, LATITUDE, LONGITUDE, SIMULATION,...
1,157
1.2K
May 27, 2011
05/11
by
Illingworth,, Garth D
texts
eye 1,157
favorite 0
comment 0
In Space Science in the Twenty-First Century, the Space Science Board of the National Research Council identified high-resolution-interferometry and high-throughput instruments as the imperative new initiatives for NASA in astronomy for the two decades spanning 1995 to 2015. In the optical range, the study recommended an 8 to 16-meter space telescope, destined to be the successor of the Hubble Space Telescope (HST), and to complement the ground-based 8 to 10-meter-class telescopes presently...
Topics: MANAGEMENT SYSTEMS, NETWORKS, THREE DIMENSIONAL MODELS, COMMUNICATING, INPUT/OUTPUT ROUTINES,...
283
283
Jun 2, 2011
06/11
by
Neri, David; Mallis, Meliss
texts
eye 283
favorite 0
comment 0
This flight simulator study examined whether regularly spaced brief bouts of controlled physical activity (standing up, walking, stretching) combined with social interaction could improve alertness and performance during a long, uneventful, overnight flight requiring extended wakefulness and vigilance. The data obtained from this study support NASA's Aero-Space Technology Enterprise and its objective of reducing the aircraft accident rate Fourteen two-man crews flew a 6-hour 12:00- 8:00 a.m.)...
Topics: THREE DIMENSIONAL MODELS, COMPUTER TECHNIQUES, MATHEMATICAL MODELS, ULTRASONICS, TOMOGRAPHY,...
96
96
Jun 2, 2011
06/11
by
Zilliac, Gregor
texts
eye 96
favorite 0
comment 0
Skin-friction distribution on surfaces of flight vehicles is desirable for several reasons. Aerodynamicists would like to know where transition occurs and if separation is present. Turbulence modelers are interested in validating skin-friction (drag) predictions. Finally, if it were possible to sum the skin-friction distribution on a lifting wind tunnel model, it would be possible to determine the viscous contribution to the total drag, a quantity not readily measured independently of the...
Topics: PLANETARY SYSTEMS, NEBULAE, DUST, METEORITES, COMETS, THREE DIMENSIONAL MODELS, ASTEROIDS,...
188
188
Jun 12, 2011
06/11
by
Nishikawa, K. I.; Hardee, P.; Hededal, C. B.; Richardson, G.; Sol, H.; Preece, R.; Fishman, G. J
texts
eye 188
favorite 0
comment 0
Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., Buneman, Weibel and other two-stream instabilities) created in collisionless shocks are responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic jet front propagating into an ambient plasma. We find that the growth times...
Topics: EXTRATERRESTRIAL RADIATION, RADIATION SHIELDING, RADIATION TRANSPORT, THREE DIMENSIONAL MODELS,...
173
173
May 31, 2011
05/11
by
Pack, LaTunia G.; Schaeffler, Norman W.; Yao, Chung-Sheng; Seifert, Av
texts
eye 173
favorite 0
comment 0
Active flow control in the form of zero-mass-flux excitation was applied at the slat shoulder of a simplified high-lift airfoil to delay flow separation. The NASA Energy Efficient Transport (EET) supercritical airfoil was equipped with a 15% chord simply hinged leading edge slat and a 25% chord simply hinged trailing edge flap. The cruise configuration data was successfully reproduced, repeating previous experiments. The effects of flap and slat deflection angles on the performance of the...
Topics: THREE DIMENSIONAL MODELS, FLUID JETS, JET MIXING FLOW, MATHEMATICAL MODELS, WALL JETS, CURVATURE
215
215
Jun 4, 2011
06/11
by
Frink, Neal T.; Parikh, Pares
texts
eye 215
favorite 0
comment 0
TetrUSS is a suite of loosely coupled computational fluid dynamics software that is packaged into a complete flow analysis system. The system components consist of tools for geometry setup, grid generation, flow solution, visualization, and various utilities tools. Development began in 1990 and it has evolved into a proven and stable system for Euler and Navier-Stokes analysis and design of unconventional configurations. It is 1) well developed and validated, 2) has a broad base of support, and...
Topics: DAMAGE ASSESSMENT, DEBONDING (MATERIALS), DEGRADATION, DELAMINATING, CONSTRUCTION, FAILURE,...
567
567
May 6, 2010
05/10
by
Milholen, W. E., II; Jones, Greg S.; Cagle, Christopher M
texts
eye 567
favorite 0
comment 0
A new capability to test active flow control concepts and propulsion simulations at high Reynolds numbers in the National Transonic Facility at the NASA Langley Research Center is being developed. This technique is focused on the use of semi-span models due to their increased model size and relative ease of routing high-pressure air to the model. A new dual flow-path high-pressure air delivery station has been designed, along with a new high performance transonic sem -si pan wing model. The...
Topics: PROTOTYPES, THREE DIMENSIONAL MODELS, SCIENTIFIC VISUALIZATION, SOFTWARE ENGINEERING, PLANETARY...
322
322
May 30, 2011
05/11
by
Leigh, Larry; Hamidzadeh, Hamid; Tinker, Michael L
texts
eye 322
favorite 0
comment 0
An inflatable structural system that is a technology demonstrator for solar thermal propulsion and other applications is characterized for structural dynamic behavior both experimentally and computationally. The inflatable structure is a pressurized assembly developed for use in orbit to support a Fresnel lens or inflatable lenticular element for focusing sunlight into a solar thermal rocket engine. When the engine temperature reaches a pre-set level, the propellant is injected into the engine,...
Topics: COMPUTATION, THREE DIMENSIONAL MODELS, METIS, TETRAHEDRONS, MACH NUMBER, CONSERVATION,...
350
350
May 31, 2011
05/11
by
Lund, Gary K.; Starrett, William David; Jensen, Kent C
texts
eye 350
favorite 0
comment 0
As part of a NASA funded contract to develop and demonstrate a gas generator cycle hybrid rocket motor for upper stage space motor applications, the development and demonstration of a low sensitivity, high performance fuel composition was undertaken. The ultimate goal of the development program was to demonstrate successful hybrid operation (start, stop, throttling) of the fuel with high concentration (90%) hydrogen peroxide. The formulation development and lab-scale testing of a simple DOT...
Topics: THREE DIMENSIONAL MODELS, COMPUTERIZED SIMULATION, VIRTUAL REALITY, MICROGRAVITY, SOFTWARE...
377
377
Jun 9, 2011
06/11
by
Bertelsen, William D.; Shin, E. eugene; Thesken, John C.; Sutter, James K.; Martin, Ric
texts
eye 377
favorite 0
comment 0
THe objectives are: 1. To experimentally validate bi-axial plate flexural performance of PMC-Ti H/C-A286 sandwich panels for the internally pressurized RBCC combustion chamber support structure. 2. To explore ASTM 2-D plate flexure test (D 6416) to simulate the internal pressure loading and to correlate the results with analytical and FE modeling based on 2-D flexure properties.
Topics: THERMOGRAPHY, FOURIER TRANSFORMATION, PHASE CONTRAST, IMAGE PROCESSING, THREE DIMENSIONAL MODELS,...
625
625
May 31, 2011
05/11
by
Tao, W. -K.; Halverson, J.; Adler, R.; Garstang, M.; Houze, R., Jr.; LeMone, M.; Pielke, R., Sr.; Woodley, W
texts
eye 625
favorite 0
comment 0
This AMS Meteorological Monographs is dedicated to Dr. Joanne Simpson for her many pioneering research efforts in tropical meteorology during her fifty-year career. Dr. Simpson's major areas of scientific research involved the ''hot tower'' hypothesis and its role in hurricanes, structure and maintenance of trade winds, air-sea interaction, and observations and the mechanism for hurricanes and waterspouts. She was also a pioneer in cloud modeling with the first one-dimensional model and had the...
Topics: THREE DIMENSIONAL MODELS, HYDROLOGICAL CYCLE, CLIMATOLOGY, CONVECTION, COMPUTERIZED SIMULATION,...
147
147
Jun 9, 2011
06/11
by
Farassat, F.; Farris, Mar
texts
eye 147
favorite 0
comment 0
There are several approaches to the prediction of the noise from sources on high speed surfaces. Two of these are the Kirchhoff and the Ffowcs williams-Hawkings methods. It can be shown that both of these methods depend on the solution of the wave equation with mathematically similar inhomogeneous source terms. Two subsonic solutions known as Formulation 1 and 1A of Langley are simple and efficient for noise prediction. The supersonic solution known as Formulation 3 is very complicated and...
Topics: AIRCRAFT WAKES, LARGE EDDY SIMULATION, THREE DIMENSIONAL MODELS, TURBULENCE, VORTICES, AIR TRAFFIC,...
212
212
May 31, 2011
05/11
by
Bajwa, Anupa; Sweet, Ada
texts
eye 212
favorite 0
comment 0
Livingstone is a discrete, propositional logic-based inference engine that has been used for diagnosis of physical systems. We present a component-based model of a Main Propulsion System (MPS) and say how it is used with Livingstone (L2) in order to implement a diagnostic system for integrated vehicle health management (IVHM) for the Propulsion IVHM Technology Experiment (PITEX). We start by discussing the process of conceptualizing such a model. We describe graphical tools that facilitated the...
Topics: AERODYNAMICS, COMPUTATIONAL FLUID DYNAMICS, COMPRESSORS, COMPUTER AIDED DESIGN, DESIGN...
229
229
Jun 1, 2011
06/11
by
Dumbacher, Da
texts
eye 229
favorite 0
comment 0
This paper documents the transformation of NASA s Space Launch Initiative (SLI) Second Generation Reusable Launch Vehicle Program under the revised Integrated Space Transportation Plan, announced November 2002. Outlining the technology development approach followed by the original SLI, this paper gives insight into the current risk-reduction strategy that will enable confident development of the Nation s first orbital space plane (OSP). The OSP will perform an astronaut and contingency cargo...
Topics: TURBOCOMPRESSORS, SHAFTS (MACHINE ELEMENTS), ROTATING STALLS, ROTORS, FLOW STABILITY, MATHEMATICAL...
66
66
May 6, 2010
05/10
by
Yen, A. S.; Clark, B. C.; Ming, D. W.; Mittlefehldt, David W.; Gellert, R.; Morris, R. V
texts
eye 66
favorite 0
comment 0
The Alpha Particle X-ray Spectrometers (APXS) onboard the Mars Exploration Rovers (MER) have measured the chemical compositions of over 400 samples on the surface of Mars. Fe and Mn are among the elements which are well established by this instrumentation. Fe 2 and Mn2 have nearly the same ionic radii and distribute similarly in primary igneous rocks, maintaining a consistent Fe:Mn ratio. Upon exposure to an oxidative weathering environment, Fe 3 and Mn4 are commonly formed, and elemental...
Topics: METEORITE CRATERS, PHOTOGRAMMETRY, LASER APPLICATIONS, EARTH OBSERVATIONS (FROM SPACE), ANALOGS,...
340
340
May 31, 2011
05/11
by
Wright, Michael J.; Loomis, Mark; Papadopoulos, Perikli
texts
eye 340
favorite 0
comment 0
Computational fluid dynamics (CFD) is used to simulate the wake flow and afterbody heating of the Project Fire II ballistic reentry to Earth at 11.4 km/sec. Laminar results are obtained over a portion of the trajectory between the initial heat pulse and peak afterbody heating. Although non-catalytic forebody convective heating results are in excellent agreement with previous computations, initial predictions of afterbody heating were about a factor of two below the experimental values. Further...
Topics: COMPUTATIONAL FLUID DYNAMICS, GRID GENERATION (MATHEMATICS), CARTESIAN COORDINATES, COMPUTERIZED...
269
269
May 23, 2011
05/11
by
Head, J. W
texts
eye 269
favorite 0
comment 0
The final report is comprised of 7 journal articles that were completed during the reporting period. Topics covered include:(1) photogeologic analysis of the Magellan stereo view of six coronae; (2) the ancient age of Maxwell Montes; (3) timescale of regional plains emplacement on Venus; (4) remote and local stresses and calderas on Mars; (5) lunar linear rilles; (6) stratigraphical constraints on the duration of tessera formation on Venus; and (7) the use of magnetic signatures in identifying...
Topics: SILICON, MICROMACHINING, MANAGEMENT SYSTEMS, TECHNOLOGIES, THREE DIMENSIONAL MODELS, SINGLE...
249
249
May 31, 2011
05/11
by
Otterman, J.; Walczewski, J., et al; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.
texts
eye 249
favorite 0
comment 0
The aim of this paper is to report extreme winter/early-spring air temperature (hereinafter temperature) anomalies in mid-latitude Europe, and to discuss the underlying forcing to these interannual fluctuations. Warm advection from the North Atlantic in late winter controls the surface-air temperature, as indicated by the substantial correlation between the speed of the surface southwesterlies over the eastern North Atlantic (quantified by a specific Index Ina) and the 2-meter level air...
Topics: COMPUTATIONAL FLUID DYNAMICS, TEXTURES, THREE DIMENSIONAL MODELS, FLOW VISUALIZATION, FLOW...
281
281
May 23, 2011
05/11
by
Smart, Michael K.; Kalkhoran, Iraj M.; Benston, Jame
texts
eye 281
favorite 0
comment 0
An experimental survey of supersonic wing tip vortices has been conducted at Mach 2.5 using small performed 2.25 chords down-stream of a semi-span rectangular wing at angle of attack of 5 and 10 degrees. The main objective of the experiments was to determine the Mach number, flow angularity and total pressure distribution in the core region of supersonic wing tip vortices. A secondary aim was to demonstrate the feasibility of using cone probes calibrated with a numerical flow solver to measure...
Topics: BELTRAMI FLOW, NAVIER-STOKES EQUATION, COMPUTATIONAL FLUID DYNAMICS, THREE DIMENSIONAL MODELS,...
270
270
Jun 9, 2011
06/11
by
Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Ely, Jay J.; Richardson, Robert E.; Hatfield, Michael O
texts
eye 270
favorite 0
comment 0
An investigation was performed to study the potential for radio frequency (RF) power radiated from Portable Electronic Devices (PEDs) to create an arcing/sparking event within the fuel tank of a large transport aircraft. This paper describes the experimental methods used for measuring RF coupling to the fuel tank and Fuel Quantity Indication System (FQIS) wiring from PED sources located in the passenger cabin. To allow comparison of voltage/current data obtained in a laboratory chamber FQIS...
Topics: MATHEMATICAL MODELS, THREE DIMENSIONAL MODELS, ACOUSTIC EMISSION, WAVE PROPAGATION, FRACTURES...
301
301
May 29, 2011
05/11
by
Wright, William B.; Chung, Jame
texts
eye 301
favorite 0
comment 0
Aerodynamic performance calculations were performed using WIND on ten experimental ice shapes and the corresponding ten ice shapes predicted by LEWICE 2.0. The resulting data for lift coefficient and drag coefficient are presented. The difference in aerodynamic results between the experimental ice shapes and the LEWICE ice shapes were compared to the quantitative difference in ice shape geometry presented in an earlier report. Correlations were generated to determine the geometric features...
Topics: VORTICES, GROUND EFFECT (AERODYNAMICS), AIRCRAFT WAKES, THREE DIMENSIONAL MODELS, LARGE EDDY...
226
226
Jun 15, 2011
06/11
by
Ricci, R. J
texts
eye 226
favorite 0
comment 0
The interactive graphics computer program SPACEBAR, conceived to reduce the time and complexity associated with the development of kinematic mechanisms on the design board, was described. This program allows the direct design and analysis of mechanisms right at the terminal screen. All input variables, including linkage geometry, stiffness, and applied loading conditions, can be fed into or changed at the terminal and may be displayed in three dimensions. All mechanism configurations can be...
Topics: COMPUTERIZED SIMULATION, CRASHES, DISPLAY DEVICES, HUMAN BODY, HUMAN FACTORS ENGINEERING, COMPUTER...
238
238
Jun 2, 2011
06/11
by
Tkachuk, Oksana; Dwyer, Matthew B.; Pasareanu, Corina S
texts
eye 238
favorite 0
comment 0
A key problem in model checking open systems is environment modeling (i.e., representing the behavior of the execution context of the system under analysis). Software systems are fundamentally open since their behavior is dependent on patterns of invocation of system components and values defined outside the system but referenced within the system. Whether reasoning about the behavior of whole programs or about program components, an abstract model of the environment can be essential in...
Topics: THREE DIMENSIONAL MODELS, VARIABILITY, ANNUAL VARIATIONS, TRANSPORT THEORY, TROPICAL REGIONS, DATA...
196
196
May 23, 2011
05/11
by
Harding, David R.; Ogbuji, Linus U. T.; Freeman, Mathieu J
texts
eye 196
favorite 0
comment 0
Silicon oxynitride films were deposited by plasma-enhanced chemical-vapor deposition. The elemental composition was varied between silicon nitride and silicon dioxide: SiO(0.3)N(1.0), SiO(0.7)N(1.6), SiO(0.7)N(1.1), and SiO(1.7)N(0.%). These films were annealed in air, at temperatures of 40-240 C above the deposition temperature (260 C), to determine the stability and behavior or each composition. the biaxial modulus, biaxial intrinsic stress, and elemental composition were measured at discrete...
Topics: HUMAN IMMUNODEFICIENCY VIRUS, CRYSTAL STRUCTURE, AMINO ACIDS, THREE DIMENSIONAL MODELS,...
Thc aim of the research will be to create a model, three-dimensional mathematical. implementation. consultation and assistance to "large" restoration projects that will assist the structural analysis, allowing easier display of dynamic strain. analysis and lighting noise. It could also be a valuable tool for decision support. therefore. may simulate several possible scenarios for intervention, This model appears therefore an excellent support for recovering. ordering and monitoring...
Topics: NASA Technical Reports Server (NTRS), STRUCTURAL ANALYSIS, THREE DIMENSIONAL MODELS, PRESERVING,...
173
173
Jun 9, 2011
06/11
by
Atkins, Harold L.; Lockard, David P
texts
eye 173
favorite 0
comment 0
A method for the prediction of acoustic scatter from complex geometries is presented. The discontinuous Galerkin method provides a framework for the development of a high-order method using unstructured grids. The method's compact form contributes to its accuracy and efficiency, and makes the method well suited for distributed memory parallel computing platforms. Mesh refinement studies are presented to validate the expected convergence properties of the method, and to establish the absolute...
Topics: MATHEMATICAL MODELS, WAKES, VORTICES, LARGE EDDY SIMULATION, AIRCRAFT WAKES, THREE DIMENSIONAL...
498
498
May 31, 2011
05/11
by
NON
texts
eye 498
favorite 0
comment 0
Whether finding new applications for existing NASA technologies or developing unique marketing strategies to demonstrate them, NASA's offices are committed to identifying unique partnering opportunities. Through their efforts NASA leverages resources through joint research and development, and gains new insight into the core areas relevant to all NASA field centers. One of the most satisfying aspects of my job comes when I learn of a mission-driven technology that can be spun-off to touch the...
Topics: INTERSYMBOLIC INTERFERENCE, THREE DIMENSIONAL MODELS, TRAVELING WAVE AMPLIFIERS, COMPUTERIZED...
264
264
Jun 9, 2011
06/11
by
Posey, Joe W.; Dunn, M. H.; Farassat, F
texts
eye 264
favorite 0
comment 0
This paper addresses two aspects of duct propagation and radiation which can contribute to more efficient fan noise predictions. First, we assess the effectiveness of Rayleigh's formula as a ducted fan noise prediction tool. This classical result which predicts the sound produced by a piston in a flanged duct is expanded to include the uniform axial inflow case. Radiation patterns using Rayleigh's formula with single radial mode input are compared to those obtained from the more precise ducted...
Topics: WOVEN COMPOSITES, TWO DIMENSIONAL MODELS, THREE DIMENSIONAL MODELS, DEBONDING (MATERIALS),...
364
364
May 23, 2011
05/11
by
Britcher, Colin P
texts
eye 364
favorite 0
comment 0
This paper will briefly review previous work in wind tunnel Magnetic Suspension and Balance Systems (MSBS) and will examine the handful of systems around the world currently known to be in operational condition or undergoing recommissioning. Technical developments emerging from research programs at NASA and elsewhere will be reviewed briefly, where there is potential impact on large-scale MSBSS. The likely aerodynamic applications for large MSBSs will be addressed, since these applications...
Topics: COMPUTER TECHNIQUES, MEMBRANES, ELECTRICAL RESISTIVITY, DEPOLARIZATION, VESTIBULES, THREE...
This volume contains the papers presented at the Fifth Symposium on Numerical and Physical Aspects of Aerodynamic Flows, held at the California State University, Long Beach, from 13 to 15 January 1992. The symposium, like its immediate predecessors, considers the calculation of flows of relevance to aircraft, ships, and missiles with emphasis on the solution of two-dimensional unsteady and three-dimensional equations.
Topics: NASA Technical Reports Server (NTRS), AERODYNAMICS, COMPUTATIONAL FLUID DYNAMICS, MISSILES,...
471
471
May 31, 2011
05/11
by
Lee, Kang N.; Fox, Dennis S.; Eldridge, Jeffrey I.; Bansal, Narottam P.; Miller, Robert A.; Zhu, Dongming; Robinson, Raymond C
texts
eye 471
favorite 0
comment 0
Current state-of-the-art environmental barrier coatings (EBCs) for Si-based ceramics consist of three layers: a silicon bond coat, an intermediate mullite (3Al2O3-2SiO2) or mullite BSAS (1-xBaO-xSrO-Al2O3-2SiO2) layer, and a BSAS top coat. Areas of concern for long-term durability are environmental durability, chemical compatibility, silica volatility, phase stability, and thermal conductivity. Variants of this family of EBCs were applied to monolithic SiC and melt infiltrated SiC/SiC...
Topics: IMAGING TECHNIQUES, OPTICAL RADAR, THREE DIMENSIONAL MODELS, SPACEBORNE ASTRONOMY, ALTIMETRY,...
This report covers technical progress during the fourth quarter of the second year of NASA Sun-Earth Connections Theory Program (SECTP) contract 'The Structure and Dynamics of the Solar Corona and Inner Heliosphere,' NAS5-99188, between NASA and Science Applications International Corporation, and covers the period May 16,2001 to August 15, 2001. Under this contract SAIC and the University of California, Irvine (UCI) have conducted research into theoretical modeling of active regions, the solar...
Topics: NASA Technical Reports Server (NTRS), HELIOSPHERE, MAGNETOHYDRODYNAMICS, SOLAR PHYSICS, SOLAR...
204
204
Jun 11, 2011
06/11
by
Whittle, Jo
texts
eye 204
favorite 0
comment 0
The Scenario Creation and Simulation Process (SCASP) includes the following steps: 1) Write Requirements; 2) Write Use Cases; 3) Prioritize Use Cases; 4) Write Nominal Scenarios; 5) Identify Relationships; 6) Refine/Generalize Scenarios; 7) Transform to State Machines. SCASP provides thorough simulation of use cases before design/implementation, resulting in: 1) Reduced cost; 2) Fewer misunderstandings; 3) Reuse of executable form of use cases. SCASP gives systematic guidelines on how to 1)...
Topics: ELECTROMAGNETIC WAVE TRANSMISSION, WIRELESS COMMUNICATION, AIRCRAFT COMPARTMENTS, THREE DIMENSIONAL...
77
77
May 29, 2011
05/11
by
Geller, Marvin; Waliser, D.; Lwiza, K.; Zhang, M.; Cess, R.; Lerdau, M
texts
eye 77
favorite 0
comment 0
This final report describes the remote sensing facility that was put into place at the State University of New York (SUNY) through the support obtained from the above referenced NASA award and the associated matching funds from SUNY.
Topics: METAL OXIDE SEMICONDUCTORS, OXIDES, INVERSIONS, IMAGES, SIMULATION, THRESHOLD VOLTAGE, THREE...
309
309
May 22, 2011
05/11
by
Langer, William D.; Wilson, Robert W.; Anderson, Charles H
texts
eye 309
favorite 0
comment 0
The structure of infrared cirrus clouds is analyzed with Laplacian pyramid transforms, a form of non-orthogonal wavelets. Pyramid and wavelet transforms provide a means to decompose images into their spatial frequency components such that all spatial scales are treated in an equivalent manner. The multiscale transform analysis is applied to IRAS 100 micrometer maps of cirrus emission in the north Galactic pole region to extract features on different scales. In the maps we identify filaments,...
Topics: SCALARS, STRESS ANALYSIS, SCIENTIFIC VISUALIZATION, STREAMLINED BODIES, TENSOR ANALYSIS, TENSORS,...
3D road models are widely used in many computer applications such as racing games and driving simulations_ However, almost all high-fidelity 3D road models were generated manually by professional artists at the expense of intensive labor. There are very few existing methods for automatically generating 3D high-fidelity road networks, especially those existing in the real world. This paper presents a novel approach thai can automatically produce 3D high-fidelity road network models from real 2D...
Topics: NASA Technical Reports Server (NTRS), INTERSECTIONS, ROADS, THREE DIMENSIONAL MODELS, GEOGRAPHIC...
The objectives of this project are to: (1) perform a numerical simulation of the jet screech phenomenon; and (2) use the data of the simulations to obtain a better understanding of the physics of jet screech. The original grant period was for three years. This was extended at no cost for an extra year to allow the principal investigator time to publish the results. We would like to report that our research work and results (supported by this grant) have fulfilled both objectives of the grant....
Topics: NASA Technical Reports Server (NTRS), AEROACOUSTICS, COMPUTERIZED SIMULATION, SCREECH TONES, THREE...
Illustrations in this view-graph presentation are presented on a Bayesian approach to 3D surface reconstruction and camera calibration.Existing methods, surface analysis and modeling,preliminary surface reconstruction results, and potential applications are addressed.
Topics: NASA Technical Reports Server (NTRS), THREE DIMENSIONAL MODELS, TOPOGRAPHY, RADAR, ALBEDO, OPTICAL...
297
297
May 23, 2011
05/11
by
Lock, James A
texts
eye 297
favorite 0
comment 0
Transmission of an arbitrarily polarized plane wave by an arbitrarily oriented spheroid in the short-wavelength limit is considered in the context of ray theory. The transmitted electric field is added to the diffracted plus reflected ray-theory electric field that was previously derived to obtain an approximation to the far-zone scattered intensity in the forward hemisphere. Two different types of cross-polarization effects are found. These are: (a) a rotation of the polarization state of the...
Topics: THREE DIMENSIONAL MODELS, FLOW VISUALIZATION, INTERFACES, VIRTUAL REALITY, SUBMERGING, CONFERENCES,...
248
248
May 23, 2011
05/11
by
Steenken, William G.; Williams, John G.; Yuhas, Andrew J.; Walsh, Kevin R
texts
eye 248
favorite 0
comment 0
The F404-GE-400-powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the quality of inlet airflow during departed flight maneuvers, that is, during flight outside the normal maneuvering envelope where control surfaces have little or no effectiveness. Six nose-left and six nose-right departures were initiated at Mach numbers between 0.3 and 0.4 at an altitude of 35 kft. The entry yaw rates were approximately 40 to 90 deg/sec. Engine surges were encountered during three of the...
Topics: SCALARS, TWO DIMENSIONAL MODELS, VISUAL OBSERVATION, THREE DIMENSIONAL MODELS, COMPUTER PROGRAMS,...
227
227
Jun 9, 2011
06/11
by
Dean, Edwin B.; Unal, Resi
texts
eye 227
favorite 0
comment 0
Designing for cost is a state of mind. Of course, a lot of technical knowledge is required and the use of appropriate tools will improve the process. Unfortunately, the extensive use of weight based cost estimating relationships has generated a perception in the aerospace community that the primary way to reduce cost is to reduce weight. Wrong Based upon an approximation of an industry accepted formula, the PRICE H (tm) production-production equation, Dean demonstrated theoretically that the...
Topics: TROPOSPHERE, PROBABILITY THEORY, RADICALS, THREE DIMENSIONAL MODELS, OXIDIZERS, PHOTOCHEMICAL...
The usage model of supercomputers for scientific applications, such as computational fluid dynamics (CFD), has changed over the years. Scientific visualization has moved scientists away from looking at numbers to looking at three-dimensional images, which capture the meaning of the data. This change has impacted the system models for computing. This report details the model which is used by scientists at NASA's research centers.
Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, SCIENTIFIC VISUALIZATION,...
244
244
May 28, 2011
05/11
by
Case, Jonatha
texts
eye 244
favorite 0
comment 0
The Applied Meteorology Unit (AMU) simulated a real-time configuration of a Local Data Integration System (LDIS) using data from 15-28 February 1999. The objectives were to assess the utility of a simulated real-time LDIS, evaluate and extrapolate system performance to identify the hardware necessary to run a real-time LDIS, and determine the sensitivities of LDIS. The ultimate goal for running LDIS is to generate analysis products that enhance short-range (less than 6 h) weather forecasts...
Topics: PROTOTYPES, GROUND OPERATIONAL SUPPORT SYSTEM, APPLICATIONS PROGRAMS (COMPUTERS), THREE DIMENSIONAL...
326
326
May 23, 2011
05/11
by
BhanuSankaraRao, K.; Schuster, H.; Halford, G. R
texts
eye 326
favorite 0
comment 0
The damage mechanisms influencing the axial strain-controlled Low-Cycle Fatigue (LCF) behavior of alloy 800H at 850 C have been evaluated under conditions of equal tension/compression ramp rates (Fast-Fast (F-F): 4 X 10(sup -3)/s and Slow-Slow (S-S): 4 X 10(sup -5)/s) and asymmetrical ramp rates (Fast-Slow (F-S): 4 x 10(sup -3)/s / 4 X 10(sup -5/s and Slow-Fast (S-F): 4 X 10(sup -5) / 4 X 10(sup -3)/s) in tension and compression. The fatigue life, cyclic stress response, and fracture modes were...
Topics: RING CURRENTS, ELECTRIC FIELDS, STORMS, MAGNETOSPHERES, MAGNETIC STORMS, TEMPORAL DISTRIBUTION,...
