Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Helicopter Main Rotor Noise Determination Of Source Contributions Using Scaled Model Data
Download Helicopter Main Rotor Noise Determination Of Source Contributions Using Scaled Model Data full books in PDF, epub, and Kindle. Read online Helicopter Main Rotor Noise Determination Of Source Contributions Using Scaled Model Data ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781722429034 Total Pages :68 pages Book Rating :4.4/5 (29 download)
Book Synopsis Helicopter Main-Rotor Noise by : National Aeronautics and Space Administration (NASA)
Download or read book Helicopter Main-Rotor Noise written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-10 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic data from a test of a 40 percent model MBB BO-105 helicopter main rotor are scaled to equivalent full-scale flyover cases. The test was conducted in the anechoic open test section of the German-Dutch Windtunnel (DNW). The measured data are in the form of acoustic pressure time histories and spectra from two out-of-flow microphones underneath and foward of the model. These are scaled to correspond to measurements made at locations 150 m below the flight path of a full-scale rotor. For the scaled data, a detailed analysis is given for the identification in the data of the noise contributions from different rotor noise sources. Key results include a component breakdown of the noise contributions, in terms of noise criteria calculations of a weighted sound pressure level (dBA) and perceived noise level (PNL), as functions of rotor advance ratio and descent angle. It is shown for the scaled rotor that, during descent, impulsive blade-vortex interaction (BVI) noise is the dominant contributor to the noise. In level flight and mild climb, broadband blade-turbulent wake interaction (BWI) noise is dominant due to the absence of BVI activity. At high climb angles, BWI is reduced and self-noise from blade boundary-layer turbulence becomes the most prominent. Brooks, Thomas F. and Jolly, J. Ralph, Jr. and Marcolini, Michael A. Langley Research Center...
Book Synopsis Helicopter Main-rotor Noise: Determination of Source Contributions Using Scaled Model Data by : Thomas F. Brooks
Download or read book Helicopter Main-rotor Noise: Determination of Source Contributions Using Scaled Model Data written by Thomas F. Brooks and published by . This book was released on 1988 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Helicopter Main-rotor Noise by : Thomas F. Brooks
Download or read book Helicopter Main-rotor Noise written by Thomas F. Brooks and published by . This book was released on 1988 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1988 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis NASA Scientific and Technical Publications by :
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1989 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1988 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Monthly Catalogue, United States Public Documents by :
Download or read book Monthly Catalogue, United States Public Documents written by and published by . This book was released on 1990 with total page 1480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Monthly Catalog of United States Government Publications by :
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Handbook of Engineering Acoustics by : Gerhard Müller
Download or read book Handbook of Engineering Acoustics written by Gerhard Müller and published by Springer Science & Business Media. This book was released on 2012-11-06 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This acoustics handbook for mechanical and architectural applications is a translation of the German standard work on the subject. It not only describes the state of art of engineering acoustics but also gives practical help to engineers for solving acoustic problems. It deals with the origin, the transmission and the methods of abatement of air-borne and structure-borne sound of different kinds, from traffic to machinery and flow induced sound.
Download or read book NASA SP. written by and published by . This book was released on 1990 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1989 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Book Synopsis Aeroacoustics of Flight Vehicles by : Harvey H. Hubbard
Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Reduction of Blade-vortex Interaction Noise Using Higher Harmonic Pitch Control by :
Download or read book Reduction of Blade-vortex Interaction Noise Using Higher Harmonic Pitch Control written by and published by . This book was released on 1989 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: An acoustics test using an aeroelastically scaled rotor was conducted to examine the effectiveness of higher harmonic blade pitch control for the reduction of impulsive blade-vortex interaction (BVI) noise. A four-bladed, 110 in. diameter, articulated rotor model was tested in a heavy gas (Freon-12) medium in the Transonic Dynamics Tunnel. Noise and vibration measurements were made for a range of matched flight conditions, where prescribed (open-loop) higher harmonic pitch was superimposed on the normal (baseline) collective and cyclic trim pitch. For the inflow-microphone noise measurements, advantage was taken of the reverberance in the hard walled tunnel by using a sound power determination approach. Initial findings from on-line data processing for three of the test microphones are reported for a 4/rev (4P) collective pitch control for a range of input amplitudes and phases. By comparing these results to corresponding baseline (no control) conditions, significant noise reductions (4- 5 dB) were found for low-speed descent conditions, where helicopter BVI noise was most intense. For other rotor flight conditions, the overall noise was found to increase. All cases show increased vibration levels.
Book Synopsis Government Reports Announcements & Index by :
Download or read book Government Reports Announcements & Index written by and published by . This book was released on 1988 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Journal of the American Helicopter Society by : American Helicopter Society
Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 2001 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aeronautical Engineering: A Cumulative Index to a Continuing Bibliography (supplement 235) by :
Download or read book Aeronautical Engineering: A Cumulative Index to a Continuing Bibliography (supplement 235) written by and published by . This book was released on 1989 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
