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Author :
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ISBN 13 :
Total Pages : 42 pages
Book Rating : 4.:/5 (317 download)
Download or read book Evaluation of the Impact of Noise Metrics on Tiltrotor Aircraft Design written by and published by . This book was released on 1995 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Kelly Shelts
Publisher :
ISBN 13 :
Total Pages : 141 pages
Book Rating : 4.:/5 (123 download)
Download or read book Acoustic Evaluation of the Bell 699 Rotor on the Tiltrotor Test Rig in the National Full-scale Aerodynamics Complex 40- by 80- Foot Wind Tunnel written by Kelly Shelts and published by . This book was released on 2020 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft noise is a growing problem in the air travel industry [1]. Urban air mobility (UAM) is a new movement to use rotorcraft to fly in and between large cities to alleviate ground traffic congestion [2]. Aircraft noise will affect more people once vehicles start taking off and landing in cities. Tiltrotor vehicles are a promising concept for UAM because of their flight mode versatility. Modern tiltrotors rotate their rotors to take off vertically like a helicopter, then transition to fly forward like an airplane. Tiltrotors do not require runways while maintaining the speed and efficiency of airplanes. Tiltrotor aerodynamics are complex due to the changing flight modes, which creates complex aeroacoustic effects. Full-scale testing is needed to validate present and future acoustic prediction codes so simulations can be done to predict noise for future designs. The National Aeronautics and Space Administration (NASA) collaborated with the United States Army and Air Force to create the Tiltrotor Test Rig (TTR) to increase their proprotor testing capabilities. The TTR can test large, full-scale rotors at higher speeds than any other proprotor test rig. The TTR Checkout Test took place in the National Full-Scale Aerodynamics Complex (NFAC) from 2017 to 2018 to assess TTR function and capabilities. Microphones were used to record acoustic data during the checkout test matrix. This thesis presents and evaluates acoustic results from the TTR Checkout Test. The acoustic results were used to evaluate data processing methods and determine their effect on overall noise metrics in helicopter and airplane mode. Acoustic data quality was determined by evaluating background noise, result repeatability, and signal-to-noise ratio in all flight conditions. Acoustic relationships were identified with relationship to rotor shaft angle, blade loading, and wind tunnel speed.
Author : Alison Yan-Ka Yu
Publisher :
ISBN 13 :
Total Pages : 118 pages
Book Rating : 4.:/5 (112 download)
Download or read book Aircraft Noise Modeling of Dispersed Flight Tracks and Metrics for Assessing Impacts written by Alison Yan-Ka Yu and published by . This book was released on 2019 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The implementation of Performance Based Navigation (PBN), such as Area Navigation (RNAV) and Required Navigation Performance (RNP), has led to aircraft being able to fly designed flight tracks very precisely. This has led to communities citing the concentration of aircraft along one flight track as a noise issue because of the frequent overflights above specific areas. In order to assess the impact of frequent overflights, metrics for understanding the annoyance mechanism were necessary. The metric Nx, which is a count of the number of overflights above the A-weighted maximum sound level (L[subscript A,max]) of xdB during the day and (x-10)dB during the night, was investigated. The metric Nx required analysis of the L[subscript A,max] noise level to count as an overflight, as well as the number of overflights that represented the annoyance threshold. N60 on a peak day with 50 overflights was shown to represent at least 80% of the complaint locations at BOS, MSP, LHR, and one runway at CLT. Alternatively peak day DNL is also shown to be a possible representative noise metric and will also be investigated. A noise metric representative of the impacts of frequent overflights allowed for communication of analysis results for possibilities for dispersed flight tracks. Important ways to communicate analysis results to stakeholders included: overall increase or decrease in population exposure to N60 on a peak day with 50 overflights, the change in the number of N60 overflights for the areas of impact, and presentation of the data that allowed stakeholders to understand the impact within the boundaries of their specific representative area. These tools will allow communities to understand the noise impacts of the procedures considered and will support the stakeholder decision processes.
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ISBN 13 :
Total Pages : 552 pages
Book Rating : 4.E/5 ( download)
Download or read book Proceedings of NOISE-CON ... written by and published by . This book was released on 1996 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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ISBN 13 :
Total Pages : 176 pages
Book Rating : 4.F/5 ( download)
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1996 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : John N. Cole
Publisher :
ISBN 13 :
Total Pages : 24 pages
Book Rating : 4.3/5 (91 download)
Download or read book Evaluation of Noise Problems Anticipated with Future VTOL Aircraft written by John N. Cole and published by . This book was released on 1967 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potential noise problems anticipated with future VTOL aircraft are analyzed and discussed in general terms, and a brief review of the basic principles of noise generation of various types of propulsion systems proposed for VTOL is included. Primary consideration is given to the noise environments produced in areas adjacent to VTOL sites, since they could cause the most serious noise problem limiting the usefulness of VTOL aircraft. Contours of perceived noise levels are compared for different takeoff and landing profiles of 3-4 passenger, 60 passenger, and 25 ton-lift-crane VTOL aircraft. Criteria and methods for assessing the response of communities to noise from V-port operations are discussed along with the problem of detection of military VTOL aircraft by means of noise. Recommendations are given on the requirements for future research on these noise problems with emphasis on the need for considering noise as an integral part of the design, selection, and test of VTOL aircraft.
Author : Oleksandr Zaporozhets
Publisher : CRC Press
ISBN 13 : 0415240662
Total Pages : 435 pages
Book Rating : 4.4/5 (152 download)
Download or read book Aircraft Noise written by Oleksandr Zaporozhets and published by CRC Press. This book was released on 2011-05-13 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft noise has adverse impacts on passengers, airport staff and people living near airports, it thus limits the capacity of regional and international airports throughout the world. Reducing perceived noise of aircraft involves reduction of noise at source, along the propagation path and at the receiver. Effective noise control demands highly skilled and knowledgeable engineers. This book is for them. It shows you how accurate and reliable information about aircraft noise levels can be gained by calculations using appropriate generation and propagation models, or by measurements with effective monitoring systems. It also explains how to allow for atmospheric conditions, natural and artificial topography as well as detailing necessary measurement techniques.
Author : Ricarda L. Bennett
Publisher :
ISBN 13 :
Total Pages : 228 pages
Book Rating : 4.:/5 (317 download)
Download or read book Handbook of Aircraft Noise Metrics written by Ricarda L. Bennett and published by . This book was released on 1981 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Information is presented on 22 noise metrics that are associated with the measurement and prediction of the effects of aircraft noise. Some of the instantaneous frequency weighted sound level measures, such as A-weighted sound level, are used to provide multiple assessment of the aircraft noise level. Other multiple event metrics, such as day-night average sound level, were designed to relate sound levels measured over a period of time to subjective responses in an effort to determine compatible land uses and aid in community planning. The various measures are divided into: (1) instantaneous sound level metrics; (2) duration corrected single event metrics; (3) multiple event metrics; and (4) speech communication metrics. The scope of each measure is examined in terms of its: definition, purpose, background, relationship to other measures, calculation method, example, equipment, references, and standards.
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ISBN 13 :
Total Pages : 84 pages
Book Rating : 4.:/5 (317 download)
Download or read book Time-of-day Corrections to Aircraft Noise Metrics written by and published by . This book was released on 1980 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Henry B. Faulkner
Publisher :
ISBN 13 :
Total Pages : 178 pages
Book Rating : 4.:/5 (317 download)
Download or read book The Cost of Noise Reduction in Commercial Tilt Rotor Aircraft written by Henry B. Faulkner and published by . This book was released on 1974 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various noise goals at minimum DOC. These vehicles were spaced across the spectrum of possible noise levels from completely unconstrained to the quietest vehicle that could be designed within the study ground rules. A group of optimization parameters were varied to find the minimum DOC while other inputs were held constant and some external constraints were met. This basic variation was then extended to different aircraft sizes and technology time frames. It was concluded that reducing noise annoyance by designing for lower rotor tip speeds is a very promising avenue for future research and development. It appears that the cost of halving the annoyance compared to an unconstrained design is insignificant and the cost of halving the annoyance again is small.
Author : K. K. Ahuja
Publisher :
ISBN 13 :
Total Pages : 60 pages
Book Rating : 4.:/5 (1 download)
Download or read book Tiltrotor Aircraft Noise written by K. K. Ahuja and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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ISBN 13 :
Total Pages : 660 pages
Book Rating : 4.F/5 ( download)
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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ISBN 13 :
Total Pages : 172 pages
Book Rating : 4.:/5 (317 download)
Download or read book NASA Langley Scientific and Technical Information Output, 1995 written by and published by . This book was released on 1996 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document is a compilation of the scientific and technical information that the Langley Research Center has produced during the calendar year 1995. Included are citations for formal reports, high-numbered conference publications, high-numbered technical memorandums, contractor reports, journal articles and other publications, meeting presentations, technical talks, computer programs, tech briefs, and patents.
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ISBN 13 :
Total Pages : 872 pages
Book Rating : 4.3/5 (243 download)
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1993 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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ISBN 13 :
Total Pages : 318 pages
Book Rating : 4.:/5 (317 download)
Download or read book Strategic Planning for Aircraft Noise Route Impact Analysis: A Three Dimensional Approach written by and published by . This book was released on 1993 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Ira David Jacobson
Publisher :
ISBN 13 :
Total Pages : 430 pages
Book Rating : 4.X/5 (4 download)
Download or read book A trade-off analysis design tool written by Ira David Jacobson and published by . This book was released on 1977 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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ISBN 13 :
Total Pages : 648 pages
Book Rating : 4.3/5 (91 download)
Download or read book Noise Control Engineering Journal written by and published by . This book was released on 2002 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
