3,563 research outputs found

    The aerobraking space transfer vehicle

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    With the advent of the Space Station and the proposed Geosynchronous Operation Support Center (GeoShack) in the early 21st century, the need for a cost effective, reusable orbital transport vehicle has arisen. This transport vehicle will be used in conjunction with the Space Shuttle, the Space Station, and GeoShack. The vehicle will transfer mission crew and payloads between low earth and geosynchronous orbits with minimal cost. Recent technological advances in thermal protection systems such as those employed in the Space Shuttle have made it possible to incorporate and aerobrake on the transfer vehicle to further reduce transport costs. The research and final design configuration of the aerospace senior design team from VPISU, working in conjunction with NASA, are presented. The topic of aerobraking and focuses on the evolution of an Aerobraking Space Transfer Vehicle (ASTV), is addressed

    An advanced technology space station for the year 2025, study and concepts

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    A survey was made of potential space station missions that might exist in the 2020 to 2030 time period. Also, a brief study of the current state-of-the-art of the major subsystems was undertaken, and trends in technologies that could impact the subsystems were reviewed. The results of the survey and study were then used to arrive at a conceptual design of a space station for the year 2025. Factors addressed in the conceptual design included requirements for artificial gravity, synergies between subsystems, and the use of robotics. Suggestions are made relative to more in-depth studies concerning the conceptual design and alternative configurations

    The Emergence of a Dominant Design – a study on hydrogen prototypes

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    The notion of dominant designs deals with dominance in the market and the dominant design is thought to be dominant because of market selection forces. The notion thus ignores the possible selection that takes place in pre-market R&D stages of technological trajectories. In this paper we ask the question whether pre-market selection takes place and if this can lead to an early dominant design. Furthermore we study what selection criteria apply during this phase, in the absence of actual market criteria. We do so through an analysis of prototyping trajectories for hydrogen vehicles. Prototypes are used by firms in their internal search process towards new designs and at the same time they are means of communicating technological expectations to outsiders. In both senses, prototypes can be taken as indicators of technological trajectories in the ongoing search process of an industry for the dominant prototype design of the future. Using prototypes as representation of intermediate outcomes of the search process, a dominant design can possibly be recognized also in a pre-market phase of development. We analyzed the designs of prototypes of hydrogen passenger cars from the 1970s till 2008. In our analysis we try to show to what extent the designs configurations of the technological components, converge or diverge over time. For this we compiled a database of 224 prototypes of hydrogen passenger cars. The database describes: the car’s manufacturer, year of construction, type of drivetrain, fuel cell type, and capacity of its hydrogen storage system. We draw conclusions with regard to the convergence/divergence of the prototypes’ designs and the role of diverse performance criteria therein. We conclude that there is convergence towards a dominant design in the prototyping phase; the PEM fuel cell combined with high pressure storage. Performance played a role as selection criterion, but so did regulation and strategic behaviour of the firms. Especially imitation dynamics, with industry leaders and followers, seems to be the major explanatory factor.Dominant design, expectations, prototypes, hydrogen, fuel cell

    Techniques utilized in the simulated altitude testing of a 2D-CD vectoring and reversing nozzle

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    Simulated altitude testing of a two-dimensional, convergent-divergent, thrust vectoring and reversing exhaust nozzle was accomplished. An important objective of this test was to develop test hardware and techniques to properly operate a vectoring and reversing nozzle within the confines of an altitude test facility. This report presents detailed information on the major test support systems utilized, the operational performance of the systems and the problems encountered, and test equipment improvements recommended for future tests. The most challenging support systems included the multi-axis thrust measurement system, vectored and reverse exhaust gas collection systems, and infrared temperature measurement systems used to evaluate and monitor the nozzle. The feasibility of testing a vectoring and reversing nozzle of this type in an altitude chamber was successfully demonstrated. Supporting systems performed as required. During reverser operation, engine exhaust gases were successfully captured and turned downstream. However, a small amount of exhaust gas spilled out the collector ducts' inlet openings when the reverser was opened more than 60 percent. The spillage did not affect engine or nozzle performance. The three infrared systems which viewed the nozzle through the exhaust collection system worked remarkably well considering the harsh environment

    Forty Years of Computational Fluid Dynamics Research in India-Achievements and Issues

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    A review of the emergence and maturing of computational fluid dynamics (CFD) research in India over the last four decades is presented. The status of in-house developed CFD codes in various aerospace laboratories and academic institutions in the country is described along with their strengths and weaknesses. Although, some level of maturity is achieved in CFD to address the external flow problems of an aerospace vehicle, the slow growth of indigenous reacting CFD codes forced Indian aerospace industry to depend solely on the commercial software for addressing the internal flow problems related to propulsion and combustion. A brief account of various technical and managerial issues in CFD development is presented. A roadmap is proposed for the graduation of CFD codes, from analysis tool to design tool.Defence Science Journal, 2010, 60(6), pp.567-576, DOI:http://dx.doi.org/10.14429/dsj.60.60

    NASA thesaurus. Volume 1: Hierarchical Listing

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    There are over 17,000 postable terms and nearly 4,000 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary and Volume 3 - Definitions

    NASA Thesaurus. Volume 1: Hierarchical listing

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    There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

    Monitoring the waste to energy plant using the latest AI methods and tools

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    Solid wastes for instance, municipal and industrial wastes present great environmental concerns and challenges all over the world. This has led to development of innovative waste-to-energy process technologies capable of handling different waste materials in a more sustainable and energy efficient manner. However, like in many other complex industrial process operations, waste-to-energy plants would require sophisticated process monitoring systems in order to realize very high overall plant efficiencies. Conventional data-driven statistical methods which include principal component analysis, partial least squares, multivariable linear regression and so forth, are normally applied in process monitoring. But recently, latest artificial intelligence (AI) methods in particular deep learning algorithms have demostrated remarkable performances in several important areas such as machine vision, natural language processing and pattern recognition. The new AI algorithms have gained increasing attention from the process industrial applications for instance in areas such as predictive product quality control and machine health monitoring. Moreover, the availability of big-data processing tools and cloud computing technologies further support the use of deep learning based algorithms for process monitoring. In this work, a process monitoring scheme based on the state-of-the-art artificial intelligence methods and cloud computing platforms is proposed for a waste-to-energy industrial use case. The monitoring scheme supports use of latest AI methods, laveraging big-data processing tools and taking advantage of available cloud computing platforms. Deep learning algorithms are able to describe non-linear, dynamic and high demensionality systems better than most conventional data-based process monitoring methods. Moreover, deep learning based methods are best suited for big-data analytics unlike traditional statistical machine learning methods which are less efficient. Furthermore, the proposed monitoring scheme emphasizes real-time process monitoring in addition to offline data analysis. To achieve this the monitoring scheme proposes use of big-data analytics software frameworks and tools such as Microsoft Azure stream analytics, Apache storm, Apache Spark, Hadoop and many others. The availability of open source in addition to proprietary cloud computing platforms, AI and big-data software tools, all support the realization of the proposed monitoring scheme

    Aeronautical Engineering: A special bibliography with indexes, supplement 55

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    This bibliography lists 260 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1975
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