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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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NASA NTRS2006

NASA Earth Sciences Data Support System and Services for the Northern Eurasia Earth Science Partnership Initiative

The presentation describes the recently awarded ACCESS project to provide data management of NASA remote sensing data for the Northern Eurasia Earth Science Partnership Initiative (NEESPI). The project targets integration of remote sensing data from MODIS, and other NASA instruments on board US-satellites (with potential expansion to data from non-US satellites), customized data products from climatology data sets (e.g., ISCCP, ISLSCP) and model data (e.g., NCEP/NCAR) into a single, well-architected data management system. It will utilize two existing components developed by the Goddard Earth Sciences Data & Information Services Center (GES DISC) at the NASA Goddard Space Flight Center: (1) online archiving and distribution system, that allows collection, processing and ingest of data from various sources into the online archive, and (2) user-friendly intelligent web-based online visualization and analysis system, also known as Giovanni. The former includes various kinds of data preparation for seamless interoperability between measurements by different instruments. The latter provides convenient access to various geophysical parameters measured in the Northern Eurasia region without any need to learn complicated remote sensing data formats, or retrieve and process large volumes of NASA data. Initial implementation of this data management system will concentrate on atmospheric data and surface data aggregated to coarse resolution to support collaborative environment and climate change studies and modeling, while at later stages, data from NASA and non-NASA satellites at higher resolution will be integrated into the system.

Leptoukh, Gregory↗
NASA NTRS2006

The NASA Software Research Infusion Initiative: Successful Technology Transfer for Software Assurance

New processes, methods and tools are constantly appearing in the field of software engineering. Many of these augur great potential in improving software development processes, resulting in higher quality software with greater levels of assurance. However, there are a number of obstacles that impede their infusion into software development practices. These are the recurring obstacles common to many forms of research. Practitioners cannot readily identify the emerging techniques that may most benefit them, and cannot afford to risk time and effort in evaluating and experimenting with them while there is still uncertainty about whether they will have payoff in this particular context. Similarly, researchers cannot readily identify those practitioners whose problems would be amenable to their techniques and lack the feedback from practical applications necessary to help them to evolve their techniques to make them more likely to be successful. This paper describes an ongoing effort conducted by a software engineering research infusion team, and the NASA Research Infusion Initiative, established by NASA s Software Engineering Initiative, to overcome these obstacles.

Hinchey, Michael G.↗
NASA NTRS1994

Initiating Formal Requirements Specifications with Object-Oriented Models

This paper reports results of an investigation into the suitability of object-oriented models as an initial step in developing formal specifications. The requirements for two critical system-level software modules were used as target applications. It was found that creating object-oriented diagrams prior to formally specifying the requirements enhanced the accuracy of the initial formal specifications and reduced the effort required to produce them. However, the formal specifications incorporated some information not found in the object-oriented diagrams, such as higher-level strategy or goals of the software.

requirements specifications↗
NASA NTRS2006

Crack Initiation and Growth in Rigid Polymeric Closed-Cell Foam Cryogenic Applications

Cryogenic vessels, such as the Space Shuttle External Tank, are often insulated with closed-cell foam because of its low thermal conductivity. The coefficient of thermal expansion mismatch between the foam and metallic substrate places the foam under a biaxial tension gradient through the foam thickness. The total foam thickness affects the slope of the stress gradient and is considered a significant contributor to the initiation of subsurface cracks. Rigid polymeric foams are brittle in nature and any subsurface cracks tend to propagate a finite distance toward the surface. This presentation investigates the relationship between foam thickness and crack initiation and subsequent crack growth, using linear elastic fracture mechanics, in a rigid polymeric closed-cell foam through analysis and comparison with experimental results.

Sayyah, Tarek↗
NASA NTRS2006

Initial Al-26/Al-27 in Carbonaceous-chondrite Chondrules: Too little Al-26 to Melt Asteroids

We report Mg-26 excesses correlated with Al/Mg ratios in five chondrules from the primitive CO3.0 chondrite Yamato 81020 that yield a mean initial Al-26/Al-27 ratio of only (3.8 +/- 0.7) x 10(exp -6) about half that of ordinary chondrite (OC)chondrules. Even if asteroids formed immediately after chondrule formation, this ratio and the mean Al content of CO chondrites is only capable of raising the temperature of a well-insulated CO asteroid to 940 K, which is more than 560 K too low to produce differentiation. The same ratio combined with the higher Al content of CV chondrites results in a CV asteroid temperature of 1100 K. We calculate that the mean initial Al-26/Al-27 ratio of about 7.4 x 10(exp -6) found in LL chondrules is only able to produce small amounts of melting, too little to produce differentiation. These results cast serious doubt on the viability of Al-26 as the heat source responsible for asteroid differentiation. Inclusion of raises temperatures about 160 K, but this increment is not enough to cause differentiation, even of an LL-chondrite asteroid.

McKeegan, Kevin D.↗
NASA NTRS2006

Status, Plans, and Initial Results for ARES 1 Crew Launch Vehicle Aerodynamics

Following the completion of NASA's Exploration Systems Architecture Study in August 2004 for the NASA Exploration Systems Mission Directorate (ESMD), the Exploration Launch Office at the NASA Marshall Space Flight Center was assigned project management responsibilities for the design and development of the first vehicle in the architecture, the Ares I Crew Launch Vehicle (CLV), which will be used to launch astronauts to low earth orbit and rendezvous with either the International Space Station or the ESMD s earth departure stage for lunar or other future missions beyond low Earth orbit. The primary elements of the Ares I CLV project are the first stage, the upper stage, the upper stage engine, and vehicle integration. Within vehicle integration is an effort in integrated design and analysis which is comprised of a number of technical disciplines needed to support vehicle design and development. One of the important disciplines throughout the life of the project is aerodynamics. This paper will present the status, plans, and initial results of Ares I CLV aerodynamics as the project was preparing for the Ares I CLV Systems Requirements Review. Following a discussion of the specific interactions with other technical panels and a status of the current activities, the plans for aerodynamic support of the Ares I CLV until the initial crewed flights will be presented.

Huebner, Lawrence D.↗
NASA NTRS2006

An Initial Non-Equilibrium Porous-Media Model for CFD Simulation of Stirling Regenerators

The objective of this paper is to define empirical parameters (or closwre models) for an initial thermai non-equilibrium porous-media model for use in Computational Fluid Dynamics (CFD) codes for simulation of Stirling regenerators. The two CFD codes currently being used at Glenn Research Center (GRC) for Stirling engine modeling are Fluent and CFD-ACE. The porous-media models available in each of these codes are equilibrium models, which assmne that the solid matrix and the fluid are in thermal equilibrium at each spatial location within the porous medium. This is believed to be a poor assumption for the oscillating-flow environment within Stirling regenerators; Stirling 1-D regenerator models, used in Stirling design, we non-equilibrium regenerator models and suggest regenerator matrix and gas average temperatures can differ by several degrees at a given axial location end time during the cycle. A NASA regenerator research grant has been providing experimental and computational results to support definition of various empirical coefficients needed in defining a noa-equilibrium, macroscopic, porous-media model (i.e., to define "closure" relations). The grant effort is being led by Cleveland State University, with subcontractor assistance from the University of Minnesota, Gedeon Associates, and Sunpower, Inc. Friction-factor and heat-transfer correlations based on data taken with the NASAlSunpower oscillating-flow test rig also provide experimentally based correlations that are useful in defining parameters for the porous-media model; these correlations are documented in Gedeon Associates' Sage Stirling-Code Manuals. These sources of experimentally based information were used to define the following terms and parameters needed in the non-equilibrium porous-media model: hydrodynamic dispersion, permeability, inertial coefficient, fluid effective thermal conductivity (including themal dispersion and estimate of tortuosity effects}, and fluid-solid heat transfer coefficient. Solid effective thermal conductivity (including the effect of tortuosity) was also estimated. Determination of the porous-media model parameters was based on planned use in a CFD model of Infinia's Stirling Technology Demonstration Convertor (TDC), which uses a random-fiber regenerator matrix. The non-equilibrium porous-media model presented is considered to be an initial, or "draft," model for possible incorporation in commercial CFD codes, with the expectation that the empirical parameters will likely need to be updated once resulting Stirling CFD model regenerator and engine results have been analyzed. The emphasis of the paper is on use of available data to define empirical parameters (and closure models) needed in a thermal non-equilibrium porous-media model for Stirling regenerator simulation. Such a model has not yet been implemented by the authors or their associates. However, it is anticipated that a thermal non-equilibrium model such as that presented here, when iacorporated in the CFD codes, will improve our ability to accurately model Stirling regenerators with CFD relative to current thermal-equilibrium porous-media models.

Tew, Roy↗
NASA NTRS2007

Post-Newtonian Black-Hole Inspiral Initial Data with Waves for Puncture Simulations

We present post-Newtonian-inspired initial data for non-spinning black-hole binaries, suitable for numerical evolution with punctures. We revisit the work of Tichey et al. and explicitly calculate remaining integral terms.Thereby we improve the accuracy in the far zone, by including realistic gravitational waves in the initial data. We investigate the behavior of this data both at the center of mass and in the far zone, demonstrating agreement of the transverse-traceless parts of the new metric with quadrupole-approximation waveforms. An advantage of these data is that they can be used for numerical evolutions to make a direct connection between the merger waveforms and the post-Newtonian inspiral waveforms.

Kelly, B. J.↗
NASA NTRS2006

Aviation Applications for Satellite-Based Observations of Cloud Properties, Convection Initiation, In-flight Icing, Turbulence and Volcanic Ash

Advanced Satellite Aviation Weather Products (ASAP) was jointly initiated by the NASA Applied Sciences Program and the NASA Aviation Safety and Security Program in 2002. The initiative provides a valuable bridge for transitioning new and existing satellite information and products into Federal Aviation Administration (FAA) Aviation Weather Research Program (AWRP) efforts to increase the safety and efficiency of the airspace system. The ASAP project addresses hazards such as convective weather, turbulence (clear-air and cloud-induced), icing and volcanic ash and is particularly applicable in extending the monitoring of weather over data-sparse areas such as the oceans and other observationally remote locations. ASAP research is conducted by scientists from NASA, the FAA AWRP's Product Development Teams (PDT), NOAA and the academic research community. In this paper we provide a summary of activities since the inception of ASAP that emphasize the use of current-generation satellite technologies toward observing and mitigating specified aviation hazards. A brief overview of future ASAP goals is also provided in light of the next generation of satellite sensors (e.g., hyperspectral; high spatial resolution) to become operational in the 2006-2013 timeframe.

Mecikalski, John R.↗
NASA NTRS2007

Multi-Objective Online Initialization of Spacecraft Formations

This paper extends a previously developed method for finding spacecraft initial conditions (ICs) that minimize the drift resulting from J2 disturbances while also minimizing the fuel required to attain those ICs. It generalizes the single spacecraft optimization to a formation-wide optimization valid for an arbitrary number of vehicles. Additionally, the desired locations of the spacecraft, separate from the starting location, can be specified, either with respect to a reference orbit, or relative to the other spacecraft in the formation. The three objectives (minimize drift, minimize fuel, and maintain a geometric template) are expressed as competing costs in a linear optimization, and are traded against one another through the use of scalar weights. By carefully selecting these weights and re-initializing the formation at regular intervals, a closed-loop, formation-wide control system is created. This control system can be used to reconfigure the formations on the fly, and creates fuel-efficient plans by placing the spacecraft in semi-invariant orbits. The overall approach is demonstrated through nonlinear simulations for two formations a GEO orbit, and an elliptical orbit.

Jeffrey, Matthew↗
NASA NTRS2007

Initial Retrieval Validation from the Joint Airborne IASI Validation Experiment (JAIVEx)

The Joint Airborne IASI Validation Experiment (JAIVEx) was conducted during April 2007 mainly for validation of the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite, but also included a strong component focusing on validation of the Atmospheric InfraRed Sounder (AIRS) aboard the AQUA satellite. The cross validation of IASI and AIRS is important for the joint use of their data in the global Numerical Weather Prediction process. Initial inter-comparisons of geophysical products have been conducted from different aspects, such as using different measurements from airborne ultraspectral Fourier transform spectrometers (specifically, the NPOESS Airborne Sounder Testbed Interferometer (NAST-I) and the Scanning-High resolution Interferometer Sounder (S-HIS) aboard the NASA WB-57 aircraft), UK Facility for Airborne Atmospheric Measurements (FAAM) BAe146-301 aircraft insitu instruments, dedicated dropsondes, radiosondes, and ground based Raman Lidar. An overview of the JAIVEx retrieval validation plan and some initial results of this field campaign are presented.

Zhou, Daniel K.↗
NASA NTRS2008

Status, Plans and Initial Results for Ares I Crew Launch Vehicle Aerodynamics

Following the completion of NASA s Exploration Systems Architecture Study in August 2004 for the NASA Exploration Systems Mission Directorate (ESMD), the Ares Projects Office at the NASA Marshall Space Flight Center was assigned project management responsibilities for the design and development of the first vehicle in the architecture, the Ares I Crew Launch Vehicle (CLV), which will be used to launch astronauts to low earth orbit and rendezvous with either the International Space Station or the ESMD s earth departure stage for lunar or other future missions beyond low Earth orbit. The primary elements of the Ares I CLV project are the first stage, the upper stage, the upper stage engine, and vehicle integration. Within vehicle integration is an effort in integrated design and analysis which is comprised of a number of technical disciplines needed to support vehicle design and development. One of the important disciplines throughout the life of the project is aerodynamics. This paper will present the status, plans, and initial results of Ares I CLV aerodynamics as the project was preparing for the Ares I CLV Systems Requirements Review. Following a discussion of the specific interactions with other technical panels and a status of the current activities, the plans for aerodynamic support of the Ares I CLV until the initial crewed flights will be presented. Keywords: Ares I Crew Launch Vehicle, aerodynamics, wind tunnel testing, computational fluid dynamics

Huebner, Lawrence D.↗
NASA NTRS2008

Initial Integration of Noise Prediction Tools for Acoustic Scattering Effects

This effort provides an initial glimpse at NASA capabilities available in predicting the scattering of fan noise from a non-conventional aircraft configuration. The Aircraft NOise Prediction Program, Fast Scattering Code, and the Rotorcraft Noise Model were coupled to provide increased fidelity models of scattering effects on engine fan noise sources. The integration of these codes led to the identification of several keys issues entailed in applying such multi-fidelity approaches. In particular, for prediction at noise certification points, the inclusion of distributed sources leads to complications with the source semi-sphere approach. Computational resource requirements limit the use of the higher fidelity scattering code to predict radiated sound pressure levels for full scale configurations at relevant frequencies. And, the ability to more accurately represent complex shielding surfaces in current lower fidelity models is necessary for general application to scattering predictions. This initial step in determining the potential benefits/costs of these new methods over the existing capabilities illustrates a number of the issues that must be addressed in the development of next generation aircraft system noise prediction tools.

Nark, Douglas M.↗
NASA NTRS2008

STEREO/SECCHI Stereoscopic Observations Constraining the Initiation of Polar Coronal Jets

We report on the first stereoscopic observations of polar coronal jets made by the EUVI/SECCHI imagers on board the twin STEREO spacecraft. The significantly separated viewpoints (approximately 11 degrees ) allowed us to infer the 3D dynamics and morphology of a well-defined EUV coronal jet for the first time. Triangulations of the jet's location in simultaneous image pairs led to the true 3D position and thereby its kinematics. Initially the jet ascends slowly at approximately equal to 10-20 kilometers per second and then, after an apparent 'jump' takes place, it accelerates impulsively to velocities exceeding 300 kilometers per second with accelerations exceeding the solar gravity. Helical structure is the most important geometrical feature of the jet which shows evidence of untwisting. The jet structure appears strikingly different from each of the two STEREO viewpoints: face-on in the one viewpoint and edge-on in the other. This provides conclusive evidence that the observed helical structure is real and is not resulting from possible projection effects of single viewpoint observations. The clear demonstration of twisted structure in polar jets compares favorably with synthetic images from a recent MHD simulation of jets invoking magnetic untwisting as their driving mechanism. Therefore, the latter can be considered as a viable mechanism for the initiation of polar jets.

Patsourakos, S.↗
NASA NTRS2008

Initial Observations of the Magnetic Field Measurements on the C/NOFS Satellite

The Vector Electric Field Instrument (VEFI) suite onboard the C/NOFS spacecraft includes a sensitive fluxgate magnetometer to measure DC and ULF magnetic fields in the low latitude ionosphere. The instrument includes a DC vector measurement at 1 sample/sec with a range of +/- 45,000 nT whose primary objective is to enable a V x B measurement that is more accurate than that provided by using a magnetic field model. These data will also be used to provide signatures of large-scale ionospheric current systems, which, when analyzed in conjunction with the C/NOFS DC electric field measurements, promise to advance our understanding of equatorial electrodynamics. The instrument also includes an AC-coupled vector measurement in the 0.05 - 8 Hz frequency range at 16 samples/sec with an output range of +/- 900 nT in order to measure small-scale current filaments and possible Alfven waves associated with plasma irregularities. We compare the Earth's magnetic field models such as the most recently updated IGRF (the International Geomagnetic Reference Field) model and the POMME (the POtsdam Magnetic Model of the Earth) model with the measurements in order to provide an in-flight "calibration" of the data as well as compute magnetic field differences to reveal large scale ionospheric currents. Our initial results show that, on average, the POMME model accurately reproduces the C/NOFS-measured magnetic field within 20 nT in magnitude and within 0.1 deg in field direction everywhere in the low latitude ionosphere except in the region of the South Atlantic Anomaly. Initial results of the C/NOFS magnetic field measurements will be shown.

Le, Guan↗
NASA NTRS2009

Self-Consistent Model of Magnetospheric Electric Field, Ring Current, Plasmasphere, and Electromagnetic Ion Cyclotron Waves: Initial Results

Further development of our self-consistent model of interacting ring current (RC) ions and electromagnetic ion cyclotron (EMIC) waves is presented. This model incorporates large scale magnetosphere-ionosphere coupling and treats self-consistently not only EMIC waves and RC ions, but also the magnetospheric electric field, RC, and plasmasphere. Initial simulations indicate that the region beyond geostationary orbit should be included in the simulation of the magnetosphere-ionosphere coupling. Additionally, a self-consistent description, based on first principles, of the ionospheric conductance is required. These initial simulations further show that in order to model the EMIC wave distribution and wave spectral properties accurately, the plasmasphere should also be simulated self-consistently, since its fine structure requires as much care as that of the RC. Finally, an effect of the finite time needed to reestablish a new potential pattern throughout the ionosphere and to communicate between the ionosphere and the equatorial magnetosphere cannot be ignored.

Gamayunov, K. V.↗
NASA NTRS2009

Residual Stresses and Critical Initial Flaw Size Analyses of Welds

An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). A series of weld analyses are performed to determine the residual stresses in a critical region of the USS. Weld residual stresses both increase constraint and mean stress thereby having an important effect on the fatigue life. The purpose of the weld analyses was to model the weld process using a variety of sequences to determine the 'best' sequence in terms of weld residual stresses and distortions. The many factors examined in this study include weld design (single-V, double-V groove), weld sequence, boundary conditions, and material properties, among others. The results of this weld analysis are included with service loads to perform a fatigue and critical initial flaw size evaluation.

Brust, Frederick W.↗
NASA NTRS2007

Synthesis of Poly-Silicon Thin Films on Glass Substrate Using Laser Initiated Metal Induced Crystallization of Amorphous Silicon for Space Power Application

Poly-silicon thin films on glass substrates are synthesized using laser initiated metal induced crystallization of hydrogenated amorphous silicon films. These films can be used to fabricate solar cells on low cost glass and flexible substrates. The process starts by depositing 200 nm amorphous silicon films on the glass substrates. Following this, 200 nm of sputtered aluminum films were deposited on top of the silicon layers. The samples are irradiated with an argon ion cw laser beam for annealing. Laser power densities ranging from 4 to 9 W/cm2 were used in the annealing process. Each area on the sample is irradiated for a different exposure time. Optical microscopy was used to examine any cracks in the films and loss of adhesion to the substrates. X-Ray diffraction patterns from the initial results indicated the crystallization in the films. Scanning electron microscopy shows dendritic growth. The composition analysis of the crystallized films was conducted using Energy Dispersive x-ray Spectroscopy. The results of poly-silicon films synthesis on space qualified flexible substrates such as Kapton are also presented.

Abu-Safe, Husam H.↗