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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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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Shuttle near-field environmental impacts - Conclusions and observations for launching at other locations

Near field and far field environmental monitoring activities extending from the first launch of the Space Shuttle at the Kennedy Space Center have provided a database from which conclusions can now be drawn for short term, acute effects of launch and, to a lesser degree, long term cumulative effects on the natural environment. Data for the first 15 launches of the Space Shuttle from Kennedy Space Center Pad 39A are analyzed for statistical significance and reduced to graphical presentations of individual and collective disposition isopleths, summarization of observed environmental impacts (e.g., vegetation damage, fish kills), and supporting data from specialized experiments and laboratory analyses. Conclusions are drawn with regard to the near field environment at Pad A, the effects on the lagoonal complex, and the relationships of these data and conclusions to upcoming operations at Complex 39 Pad B where the environment is significantly different. The paper concludes with a subjective evaluation of the likely impacts at Vandenberg Space Launch Complex 6 for the first Shuttle launch next year.

Koller, A. M., Jr.↗
NASA NTRS1975

Conclusions

Conclusions are presented according to general areas of technology with some specific examples of research and technology needs identified. These conclusions provide a base for the future development of detailed program plans and identify research needs that are not being given attention or are not being supported at a sufficient level. Emphasis is placed on hydrogen production and use.

Source record↗
NASA NTRS2009

Conclusions and Recommendations

This chapter provides a brief wrap-up of the task group report and focuses on the overall conclusions and recommendations for future work for the CAWAPI and VFE-2 facets beyond the task group. The overall conclusion is that the Technology Readiness Level (TRL) of CFD solvers has been improved in predicting the flow-physics of vortex-dominated flows during the work of the task group, by having flight and wind-tunnel data available for comparison. Moreover, like all good scientific studies, this task group has identified flight conditions on the F-16XL airplane or wind-tunnel test conditions for a specific leading-edge radius on the 65 delta-wing model where the TRL still needs to be increased.

Lamar, John E.↗
NASA NTRS1973

Conclusions and recommendations

Conclusions and recommendations are presented for an analysis of the total energy situation; the effect of the energy problem on air transportation; and hydrogen fuel for aircraft. Properties and production costs of fuels, future prediction for energy and transportation, and economic aspects of hydrogen production are appended.

Source record↗
NASA NTRS1973

Some conclusions regarding the aeroelastic stability of hingeless helicopter blades in hover and in forward flight

In this paper results and conclusions obtained from the study of the aeroelastic instability of hingeless helicopter blades are presented. First, the large amplitude coupled flap-lag equations of motion of a hingeless elastic helicopter blade are solved using an asymptotic expansion procedure in multiple time scales. Both hover and forward flight cases are considered. Stability boundaries and amplitudes of nonlinear response are obtained. From these, the importance of the nonlinear coupling and the effect of the periodic coefficients is determined. Next, using a system of linearized coupled flap-lag-pitch equations in hover, various divergence mechanisms for hingeless blades are shown. Finally, the flutter boundaries for coupled flap-lag-pitch are obtained. The effect of the torsional degree of freedom on the flap-lag type of instability is investigated. Similarly the effect of lag on the flap-pitch type of instability is considered. In addition, the effect of various blade parameters on the stability boundaries is shown.

Friedmann, P.↗
NASA NTRS1978

An investigation of wing buffeting response at subsonic and transonic speeds: Phase 1: F-111A flight data analysis. Volume 1: Summary of technical approach, results and conclusions

The structural response to aerodynamic buffet during moderate to high-g maneuvers at subsonic and transonic speeds was investigated. The investigation is reported in three volumes. This volume presents a summary of the investigation with a complete description of the technical approach, description of the aircraft, its instrumentation, the data reduction procedures, results and conclusion.

Benepe, D. B.↗
NASA NTRS1978

Planning for airport access: An analysis of the San Francisco Bay area. Introduction and conclusions

The problems of airport access are examined and recommendations are made based on current transportation availability, public costs, and future transportation demand. Major conclusions presented include: (1) access must be considered in the contex of the overall urban transportation system, (2) expensive and inflexible travel modes designed primarily for airport access are not justifiable, (3) VTOL and STOL are presently too expensive for large-scale commercial use, and (4) the automobile will continue to be the predominant access mode in the future.

Source record↗
NASA NTRS1982

Conference on Complex Turbulent Flows: Comparison of Computation and Experiment, Stanford University, Stanford, CA, September 14-18, 1981, Proceedings. Volume 2 - Taxonomies, reporters' summaries, evaluation, and conclusions

Computational techniques for simulating turbulent flows were explored, together with the results of experimental investigations. Particular attention was devoted to the possibility of defining a universal closure model, applicable for all turbulence situations; however, conclusions were drawn that zonal models, describing localized structures, were the most promising techniques to date. The taxonomy of turbulent flows was summarized, as were algebraic, differential, integral, and partial differential methods for numerical depiction of turbulent flows. Numerous comparisons of theoretically predicted and experimentally obtained data for wall pressure distributions, velocity profiles, turbulent kinetic energy profiles, Reynolds shear stress profiles, and flows around transonic airfoils were presented. Simplifying techniques for reducing the necessary computational time for modeling complex flowfields were surveyed, together with the industrial requirements and applications of computational fluid dynamics techniques.

Kline, S. J.↗
NASA NTRS1987

Electron attachment in F2 - Conclusive demonstration of nonresonant, s-wave coupling in the limit of zero electron energy

Dissociative electron attachment to F2 has been observed in the energy range 0-140 meV, at a resolution of 6 meV (full width at half maximum). Results show conclusively a sharp, resolution-limited threshold behavior consistent with an s-wave cross section varying as sq rt of epsilon. Two accurate theoretical calculations predict only p-wave behavior varying as the sq rt of epsilon. Several nonadiabatic coupling effects leading to s-wave behavior are outlined.

Chutjian, A.↗
NASA NTRS1995

The foundations of reusability: Successful experience and important conclusions from planning and scheduling of space operations

NASA's Office of Space Communications is sponsoring a combined technical and management initiative to dramatically decrease the cost of preparing for and conducting space operations. The authors present their successful experience and important conclusions from producing generalized and readily reusable solutions and systems for planning and scheduling applications. While generality by itself should enable reuse, generality alone may not produce the desired cost savings. Generality achieved by accumulating numerous special cases within a software system often increases the complexity of the software to the extent that maintenance costs overtake development savings. Because of this phenomenon, the authors have insisted on simplicity, as well as generality, to achieve cost-effective operation reusability. Simplicity and generality can be accomplished simultaneously when the basic 'Building Blocks' for a problem domain, in this paper, planning and scheduling, are discovered and implemented with reuse in mind. The Building Blocks for planning and scheduling are described. The authors also present examples of how these Building Blocks have accommodated various scenarios that were previously treated as mission-peculiar. Two case histories are presented to demonstrate operational reusability and cost effectiveness.

Hornstein, Rhoda Shaller↗
NASA NTRS2003

Evaluating Behaviorally Oriented Aviation Maintenance Resource Management (MRM) Training and Programs: Methods, Results, and Conclusions

Assessment of the impact of Aviation Resource Management Programs on aviation culture and performance has compelled a considerable body of research (Taylor & Robertson, 1995; Taylor, 1998; Taylor & Patankar, 2001). In recent years new methods have been applied to the problem of maintenance error precipitated by factors such as the need for self-assessment of communication and trust. The present study - 2002 -- is an extension of that past work. This research project was designed as the conclusion of a larger effort to help understand, evaluate and validate the impact of Maintenance Resource Management (MRM) training programs, and other MRM interventions on participant attitudes, opinions, behaviors, and ultimately on enhanced safety performance. It includes research and development of evaluation methodology as well as examination of psychological constructs and correlates of maintainer performance. In particular, during 2002, three issues were addressed. First, the evaluation of two (independent & different) MRM programs for changing behaviors was undertaken. In one case we were able to further apply the approach to measuring written communication developed during 2001 (Taylor, 2002; Taylor & Thomas, 2003). Second, the MRM/TOQ surveys were made available for completion on the internet. The responses from these on-line surveys were automatically linked to a results calculator (like the one developed and described in Taylor, 2002) to aid industry users in analyzing and evaluating their local survey data on the internet. Third, the main trends and themes from our research about MRM programs over the past dozen years were reviewed.

Taylor, James C.↗
NASA NTRS2005

The Status of Lunar Simulants: Conclusions and Recommendations from the 2005 Lunar Regolith Simulant Materials Workshop

No coordinated program currently exists in the U.S.A to define reference materials to be used as analogs of lunar materials. While such efforts have existed at different times in the past (Apollo Landing Module and Lunar Rover programs and NASA's Space Initiative in the early 1990's), the need for mineral materials chosen to simulate the characteristics of lunar regoliths is a pressing issue that must be addressed today through the collaboration of scientists, engineers and program managers. The 2005 Lunar Regolith Materials Workshop was held at Marshall Space Flight Center in Huntsville, AL on January 24-26,2005 to launch a focused effort of defining the requirements of lunar >simulant materials and make specific recommendations to NASA Headquarters for their production. Nearly 100 scientists and engineers worked during 3 days to accomplish these goals. Their conclusions and recommendations will be presented.

Sibille, L.↗
NASA NTRS2002

The successful conclusion of the Deep Space 1 Mission: important results without a flashy title

In September 2001, Deep Space 1 (DS1) completed a high-risk and flawless encounter with comet 19P/Borrelly. Its data provide a detailed view of this comet and offere surprising and exciting insights. With this successful conclusion of its extended mission, DS1 undertook a hyperextended mission. Following this period of extremely agressive testing, with no further technology or science objectives, the mission was terminated on December 18, 2001, with the powering off of the spacecraft's trnasmitter, although the receiver was left on. By the end of its mission, DS1 had returned a wealth of important science data and engineering data for future missions.

Deep Space 1 DS1 comets SEP solar electric propuls↗
NASA NTRS2010

Results and Conclusions from the NASA Isokinetic Total Water Content Probe 2009 IRT Test

The NASA Glenn Research Center has developed and tested a Total Water Content Isokinetic Sampling Probe. Since, by its nature, it is not sensitive to cloud water particle phase nor size, it is particularly attractive to support super-cooled large droplet and high ice water content aircraft icing studies. The instrument comprises the Sampling Probe, Sample Flow Control, and Water Vapor Measurement subsystems. Results and conclusions are presented from probe tests in the NASA Glenn Icing Research Tunnel (IRT) during January and February 2009. The use of reference probe heat and the control of air pressure in the water vapor measurement subsystem are discussed. Several run-time error sources were found to produce identifiable signatures that are presented and discussed. Some of the differences between measured Isokinetic Total Water Content Probe and IRT calibration seems to be caused by tunnel humidification and moisture/ice crystal blow around. Droplet size, airspeed, and liquid water content effects also appear to be present in the IRT calibration. Based upon test results, the authors provide recommendations for future Isokinetic Total Water Content Probe development.

Reehorst, Andrew↗
NASA NTRSDate not supplied

Conclusions of a Cryogenic Motor Configuration Study for Aircraft Propulsion

Cryogenic electric machines are a promising technology for multi megawatt electric aircraft drivetrains. Superconducting stators that make use of low AC loss superconducting wires are considered to be a key component for these cryogenic machines. This paper shares the lessons learned from a design study that evaluated several configurations of a 5 MW cryogenic motor for this application. The lessons are drawn from a qualitative study of 16 configurations and a quantitative study of 8 down selected configurations. The quantitative study involved using analytical calculations (electromagnetic, thermofluid, mechanical, and motor sizing) to determine each configuration’s Pareto front of total efficiency and total specific power. The conclusions from a preliminary assessment of different stator conductors (superconductors and cryogenic metals) are also presented. One motor configuration is down selected for future detailed design and demonstration at the multi megawatt level.

Electrified aircraft propulsion↗
DOE OSTI2024

Outcomes and Conclusions from the 2022 AM Bench Measurements, Challenge Problems, Modeling Submissions, and Conference

The Additive Manufacturing Benchmark Test Series (AM Bench) provides rigorous measurement data for validating additive manufacturing (AM) simulations for a broad range of AM technologies and material systems. AM Bench includes extensive in situ and ex situ measurements, simulation challenges for the AM modeling community, and a corresponding conference series. In 2022, the second round of AM Bench measurements, challenge problems, and conference were completed, focusing primarily upon laser powder bed fusion (LPBF) processing of metals, and both material extrusion processing and vat photopolymerization of polymers. In all, more than 100 people from 10 National Institute of Standards and Technology (NIST) divisions and 21 additional organizations were directly involved in the AM Bench 2022 measurements, data management, and conference organization. The international AM community submitted 138 sets of blind modeling simulations for comparison with the in situ and ex situ measurements, up from 46 submissions for the first round of AM Bench in 2018. Analysis of these submissions provides valuable insight into current AM modeling capabilities. The AM Bench data are permanently archived and freely accessible online. The AM Bench conference also hosted an embedded workshop on qualification and certification of AM materials and components.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Missing microbial eukaryotes and misleading meta-omic conclusions

Meta-omics is commonly used for large-scale analyses of microbial eukaryotes, including species or taxonomic group distribution mapping, gene catalog construction, and inference on the functional roles and activities of microbial eukaryotes in situ. Here, we explore the potential pitfalls of common approaches to taxonomic annotation of protistan meta-omic datasets. We re-analyze three environmental datasets at three levels of taxonomic hierarchy in order to illustrate the crucial importance of database completeness and curation in enabling accurate environmental interpretation. We show that taxonomic membership of sequence clusters estimates community composition more accurately than returning exact sequence labels, and overlap between clusters can address database shortcomings. Clustering approaches can be applied to diverse environments while continuing to exploit the wealth of annotation data collated in databases, and selecting and evaluating these databases is a critical part of correctly annotating protistan taxonomy in environmental datasets. We argue that ongoing curation of genetic resources is crucial in accurately annotating protists in in situ meta-omic datasets. Moreover, we propose that precise taxonomic annotation of meta-omic data is a clustering problem rather than a feasible alignment problem.

59 BASIC BIOLOGICAL SCIENCES↗