Download or read book ACOUSTIC TREATMENT DESIGN SCALING METHODS NASA CR 1999 209120 VOL 3 AUG 6 1999 written by and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ACOUSTIC TREATMENT DESIGN SCALING METHODS NASA CR 1999 209120 VOL 4 AUG 6 1999 written by and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ACOUSTIC TREATMENT DESIGN SCALING METHODS NASA CR 1999 209120 VOL 5 AUG 6 1999 written by and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ACOUSTIC TREATMENT DESIGN SCALING METHODS NASA CR 1999 209120 VOL1 JUL 9 1999 written by and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Treatment Design Scaling Methods Volume 1 Overview Results and Recommendations written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-25 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scale model fan rigs that simulate new generation ultra-high-bypass engines at about 1/5-scale are achieving increased importance as development vehicles for the design of low-noise aircraft engines. Testing at small scale allows the tests to be performed in existing anechoic wind tunnels, which provides an accurate simulation of the important effects of aircraft forward motion on the noise generation. The ability to design, build, and test miniaturized acoustic treatment panels on scale model fan rigs representative of the fullscale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. The primary objective of this study was to develop methods that will allow scale model fan rigs to be successfully used as acoustic treatment design tools. The study focuses on finding methods to extend the upper limit of the frequency range of impedance prediction models and acoustic impedance measurement methods for subscale treatment liner designs, and confirm the predictions by correlation with measured data. This phase of the program had as a goal doubling the upper limit of impedance measurement from 6 kHz to 12 kHz. The program utilizes combined analytical and experimental methods to achieve the objectives. Kraft, R. E. and Yu, J. Glenn Research Center; Langley Research Center NASA/CR-1999-209120/VOL1, NAS 1.26:209120/VOL1
Download or read book Acoustic Treatment Design Scaling Methods NASA written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Treatment Design Scaling Methods Phase Ii Final Report Nasa written by United States. National Aeronautics and Space Administration and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Civil Jet Aircraft Design written by Lloyd R. Jenkinson and published by Elsevier Limited. This book was released on 1999 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an increasing emphasis in aeronautical engineering on design. Concentrating on large scale commercial jet aircraft, this textbook reflects areas of growth in the aircraft industry and the procedures and practices of civil aviation design.
Download or read book Axial Flow Turbines written by J. H. Horlock and published by . This book was released on 1982 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Climatological Summaries written by and published by . This book was released on 1964 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Characteristics of Perforated Dissipative and Hybrid Silencers written by Iljae Lee and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Acoustic characteristics of silencers filled with fibrous material (hence dissipative) are investigated. Following a theoretical and experimental analysis of a single-pass, perforated, dissipative concentric silencer, the study is extended to a hybrid silencer designed by combining dissipative and reflective (Helmholtz resonator) components. The ability to model these silencers relies heavily on the understanding of the acoustic behavior of the fibrous material and the perforations. Therefore, the present study has developed two experimental setups to measure: (a) the complex characteristic impedance and the wavenumber of the fibrous material with varying filling density and texturization conditions, and (b) the acoustic impedance of perforations in contact with the fibrous material, and with and without the mean flow. New empirical expressions are then provided for the acoustic impedance of perforations with varying porosity, hole diameter, wall thickness, mean flow rate, and the fiber characteristics. The experimental results illustrate that the presence of absorbent significantly increases both the resistance and reactance of the perforation impedance. The addition of mean flow is also shown in general to increase the resistance, while decreasing the reactance particularly at low porosities. The empirical expressions for the fiber acoustic properties and the perforation impedance are then integrated into the predictions of transmission loss. These predictions are based primarily on a three-dimensional boundary element method (BEM) developed in the present study, due to its ability to treat silencers with complex internals, in addition to one- and two-dimensional analytical approaches also introduced. Comparisons of predictions with the acoustic attenuation experiments support the proposed relationships for the properties of fibrous material and the perforation impedance. The influence of the internal geometry modifications of dissipative silencers, such as baffles and extended inlet/outlet, and the impact of connecting duct length between a pair of silencers, are investigated with BEM. Hence, the contributions of the present study include the development of methodologies for the measurement of acoustic properties of the fibrous material and the impedance of perforations, particularly in contact with the absorbent along with the resulting empirical expressions, thereby assisting towards analytical and computational design tools for the dissipative and hybrid silencers.
Download or read book Deep Oil Spills written by Steven A. Murawski and published by Springer. This book was released on 2019-06-29 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for oil and gas has brought exploration and production to unprecedented depths of the world’s oceans. Currently, over 50% of the oil from the Gulf of Mexico now comes from waters in excess of 1,500 meters (one mile) deep, where no oil was produced just 20 years ago. The Deepwater Horizon oil spill blowout did much to change the perception of oil spills as coming just from tanker accidents, train derailments, and pipeline ruptures. In fact, beginning with the Ixtoc 1 spill off Campeche, Mexico in 1979-1980, there have been a series of large spill events originating at the sea bottom and creating a myriad of new environmental and well control challenges. This volume explores the physics, chemistry, sub-surface oil deposition and environmental impacts of deep oil spills. Key lessons learned from the responses to previous deep spills, as well as unresolved scientific questions for additional research are highlighted, all of which are appropriate for governmental regulators, politicians, industry decision-makers, first responders, researchers and students wanting an incisive overview of issues surrounding deep-water oil and gas production.
Download or read book Oceanobs 19 An Ocean of Opportunity Volume I written by Tong Lee and published by Frontiers Media SA. This book was released on 2020-12-31 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Download or read book Operational Oceanography in the 21st Century written by Andreas Schiller and published by Springer Science & Business Media. This book was released on 2011-04-11 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade the significant advances in real-time ocean observing systems, ocean modelling, ocean data assimilation and super-computing has seen the development and implementation of operational ocean forecast systems of the global ocean. At the conclusion of the Global Ocean Data Assimilation Experiment (GODAE) in 2008 ocean analysis and forecasting services were being supported by 12 international centres. This book is about ocean forecasting - a maturing field which remains an active area of research, and includes such topics as ocean predictability, observing system design, high resolution ocean modelling and ocean data assimilation. It presents the introduction to ocean forecasting which provides a foundation for new opportunities in areas of coupled bio-geochemical forecasting and coupled atmosphere-wave-ocean forecasting. The book describes an updated account of research and development to improve forecast systems, determining how best to service the marine user community with forecast information as well as demonstrating impact to their applications. It also discusses operational centres that are now supporting a range of real-time ocean services including online graphical and data products for their user communities and their feedback on the quality of information. The contents of this book are aimed at early career scientists and professionals with an interest in operational oceanography and related ocean science. There are excellent opportunities for exciting careers in the emerging field of operational oceanography in order to address current and future challenges as well as provide the supporting services to a rapidly growing user community.
Download or read book Very High Energy Gamma Ray Astronomy written by K.E. Turver and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Advanced Research Workshop on Very High Energy Gamma Ray Astronomy and Related Topics was held at Durham, England during August 11-15 1986. The meeting was sponsored by the Scientific Affairs Division of NATO and the University of Durham. It is four years since the first Workshop dedicated to High Energy Gamma Ray Astronomy was held at Ootacamund, India. At that meeting the developments in Very High Energy Gamma Ray Astronomy over a period of more than 20 years were reported and the methodology, limitations, improvements and prospects for further progess were discussed. The possible requirement for a follow-up meeting was clear if the optimistic future foreseen for the field at the Ooty meeting was correct. The Durham meeting was suggested to fill this role. Although the arrangements for the Durham meeting were discussed as long ago as 1983 with possible dates in 1984 or 1986, the eventual date in 1986 has proved admirable and has coincided with a time when further advances have been reported. An important feature of the proposal for the Durham meeting was the emphasis on a series of Workshop sessions, the conclusions of each to be summarized by a Rapporteur. The purpose of these sessions was to provide a consensus view of many of the important areas in the field at a time of increasing interest by the rest of the astrophysics community.
Download or read book Zonal Jets written by Boris Galperin and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The IXTOC I Oil Spill written by Craig H. Hooper and published by . This book was released on 1982 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
