Helicopter Impulsive Noise Theoretical And Experimental Status

Author : F. H. Schmitz
Publisher : Unknown
Page : 110 pages
File Size : 42,5 Mb
Release : 1983
Category : Electronic
ISBN : NASA:31769000557143

Get Book

Helicopter Impulsive Noise: Theoretical and Experimental Status by F. H. Schmitz Pdf

The theoretical and experimental status of helicopter impulsive noise is reviewed. The two major source mechanisms of helicopter impulsive noise are addressed: high-speed impulsive noise and blade-vortex interaction impulsive noise. A thorough physical explanation of both generating mechanisms is presented together with model and full-scale measurements of the phenomena. Current theoretical prediction methods are compared with experimental findings of isolated rotor tests. The noise generating mechanisms of high speed impulsive noise are fairly well understood - theory and experiment compare nicely over Mach number ranges typical of today's helicopters. For the case of blade-vortex interaction noise, understanding of noise generating mechanisms and theoretical comparison with experiment are less satisfactory. Several methods for improving theory-experiment are suggested.

Author : A. Krothapalli,C.A. Smith
Publisher : Springer Science & Business Media
Page : 511 pages
File Size : 44,7 Mb
Release : 2012-12-06
Category : Science
ISBN : 9781461248408

Get Book

Recent Advances in Aeroacoustics by A. Krothapalli,C.A. Smith Pdf

The Joint Institute for Aeronautics and Acoustics at Stanford University was established in October 1973 to provide an academic environment for long-term cooperative research between Stanford and NASA Ames Research Center. Since its establishment, the Institute has conducted theoretical and experimental work in the areas of aerodynamics, acoustics, fluid mechanics, flight dynamics, guidance and control, and human factors. This research has involved Stanford faculty, research associates, graduate students, and many distinguished visitors in collaborative efforts with the research staff of NASA Ames Research Center. The occasion of the Institute's tenth anniversary was used to reflect back on where that research has brought us, and to consider where our endeavors should be directed next. Thus, an International Symposium was held to review recent advances in the fields relevant to the activities of the Institute and to discuss the areas of research to be undertaken in the future. This anniversary was also chosen as an opportunity to honor one of the Institute's founders and its director, Professor Krishnamurty Karamcheti. It has been his crea tive inspiration that has provided the ideal research environment at the Joint Institute.

Author : Anonim
Publisher : Unknown
Page : 42 pages
File Size : 43,9 Mb
Release : 1980
Category : Electronic
ISBN : NASA:31769000547524

Get Book

Transonic Rotor Noise: Theoretical and Experimental Comparisons by Anonim Pdf

Two complementary methods of describing the high-speed rotor noise problem are discussed. The first method uses the second-order transonic potential equation to define and characterize the nature of the aerodynamic and acoustic fields and to explain the appearance of radiating shock waves. The second employs the Ffowcs Williams and Hawkings equation to successfully calculate the acoustic far-field. Good agreement between theoretical and experimental waveforms is shown for transonic hover tip Mach numbers from 0.8 to 0.9. (Author).

Author : Anonim
Publisher : Unknown
Page : 702 pages
File Size : 43,9 Mb
Release : 1995
Category : Aeronautics
ISBN : UIUC:30112048646605

Get Book

Scientific and Technical Aerospace Reports by Anonim Pdf

Author : Anonim
Publisher : Unknown
Page : 594 pages
File Size : 49,6 Mb
Release : 1984
Category : Shock (Mechanics)
ISBN : STANFORD:36105112118885

Get Book

The Shock and Vibration Digest by Anonim Pdf

Author : Andrew B. Connor
Publisher : Unknown
Page : 28 pages
File Size : 45,6 Mb
Release : 1987
Category : Helicopters
ISBN : UIUC:30112106613364

Get Book

Correlation of Helicopter Impulsive Noise from Blade-vortex Interaction with Rotor Mean Inflow by Andrew B. Connor Pdf

Author : Genevieve Comte-Bellot,John E. Fowcs-Williams
Publisher : Springer Science & Business Media
Page : 534 pages
File Size : 40,8 Mb
Release : 2013-03-09
Category : Science
ISBN : 9783642827587

Get Book

Aero- and Hydro-Acoustics by Genevieve Comte-Bellot,John E. Fowcs-Williams Pdf

The Symposium "Aero-and Hydroacoustics" was held at the Ecole Centrale de Lyon, France, on 3rd - 6 July 1985, at the initiative of the International Union of Theoretical and Applied Mechanics (IUTAM) . The research topics discussed concerned the acoustics of unstable and turbulent flows and the noise generated by movable surfaces. Other subjects of interest were thermoacoustics, diffraction, and acoustic propagation through turbulence. Applications of numerical and experimental techniques to source diagnostics were discussed, as was active noise control. In Hydroacoustics the emphasis was on noise due to flow induced vibrations. There were 8 general invited lecturers and 43 other contributors, with 150 participants form 14 countries. Sufficient time was provided for discussions and social gatherings. For example, there was the opening of the high speed anechoic wind tunnel of the Centre Acoustique, and a welcome address given by the Mayor of Lyon in his historic City Hall. The organizing Committee of the Symposium wish to express their thanks to la Direction des Recherches Etudes et Techniques du Ministere des Armees (DRET), Ie Centre National de la Recherche Scientifique (CNRS), Ie Conseil General du Rhone, l'Association Universitaire de Mecanique (AUM), Ie Ministere de l'Environnement, for financial support. Le Groupement des Acousticiens de langue frangaise (GALF) helped advertise the meeting. The organizers are also indebted to the International Union of Theoretical and Applied Mechanics for providing travel subsidies to young scientists

Author : Marian Bubak,Jacek Kitowski,Kazimierz Wiatr
Publisher : Springer
Page : 538 pages
File Size : 42,7 Mb
Release : 2014-08-25
Category : Computers
ISBN : 9783319108940

Get Book

eScience on Distributed Computing Infrastructure by Marian Bubak,Jacek Kitowski,Kazimierz Wiatr Pdf

To help researchers from different areas of science understand and unlock the potential of the Polish Grid Infrastructure and to define their requirements and expectations, the following 13 pilot communities have been organized and involved in the PLGrid Plus project: Acoustics, AstroGrid-PL, Bioinformatics, Ecology, Energy Sector, Health Sciences, HEPGrid, Life Science, Materials, Metallurgy, Nanotechnologies, Quantum Chemistry and Molecular Physics, and SynchroGrid. The book describes the experience and scientific results achieved by the project partners. Chapters 1 to 8 provide a general overview of research and development activities in the framework of the project with emphasis on services for different scientific areas and an update on the status of the PL-Grid infrastructure, describing new developments in security and middleware. Chapters 9 to 13 discuss new environments and services which may be applied by all scientific communities. Chapters 14 to 36 present how the PLGrid Plus environments, tools and services are used in advanced domain specific computer simulations; these chapters present computational models, new algorithms, and ways in which they are implemented. The book also provides a glossary of terms and concepts. This book may serve as a resource for researchers, developers and system administrators working on efficient exploitation of available e-infrastructures, promoting collaboration and exchange of ideas in the process of constructing a common European e-infrastructure.

Author : Anonim
Publisher : Unknown
Page : 492 pages
File Size : 46,9 Mb
Release : 1988
Category : Shock (Mechanics)
ISBN : STANFORD:36105007165983

Get Book

The Shock and Vibration Digest by Anonim Pdf

Author : Gordon J. Leishman
Publisher : Cambridge University Press
Page : 860 pages
File Size : 51,6 Mb
Release : 2006-04-24
Category : Science
ISBN : 0521858607

Get Book

Principles of Helicopter Aerodynamics with CD Extra by Gordon J. Leishman Pdf

Written by an internationally recognized teacher and researcher, this book provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft such as tilt rotors and autogiros. The text begins with a unique technical history of helicopter flight, and then covers basic methods of rotor aerodynamic analysis, and related issues associated with the performance of the helicopter and its aerodynamic design. It goes on to cover more advanced topics in helicopter aerodynamics, including airfoil flows, unsteady aerodynamics, dynamic stall, and rotor wakes, and rotor-airframe aerodynamic interactions, with final chapters on autogiros and advanced methods of helicopter aerodynamic analysis. Extensively illustrated throughout, each chapter includes a set of homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thoroughly revised and updated text on rotating-wing aerodynamics.

Author : Anonim
Publisher : Unknown
Page : 840 pages
File Size : 52,7 Mb
Release : 1979
Category : Mechanics, Applied
ISBN : UIUC:30112008993229

Get Book

Applied Mechanics Reviews by Anonim Pdf

Author : United States. Defense Logistics Studies Information Exchange
Publisher : Unknown
Page : 1086 pages
File Size : 45,7 Mb
Release : 1985
Category : Military research
ISBN : MINN:31951T002489833

Get Book

Annual Department of Defense Bibliography of Logistics Studies and Related Documents by United States. Defense Logistics Studies Information Exchange Pdf

Author : Anonim
Publisher : Unknown
Page : 816 pages
File Size : 51,7 Mb
Release : 1985
Category : Engineering
ISBN : STANFORD:36105133448907

Get Book

Tech Notes by Anonim Pdf

Author : Anonim
Publisher : Unknown
Page : 28 pages
File Size : 42,5 Mb
Release : 1987
Category : Science
ISBN : STANFORD:36105024803558

Get Book

NASA Technical Paper by Anonim Pdf

Author : Harvey H. Hubbard
Publisher : Unknown
Page : 620 pages
File Size : 51,6 Mb
Release : 1991
Category : Aerodynamic noise
ISBN : STANFORD:36105024722329

Get Book

Aeroacoustics of Flight Vehicles by Harvey H. Hubbard Pdf