2 edition of Laboratory experiments on active suppression of advanced turboprop noise. found in the catalog.
Laboratory experiments on active suppression of advanced turboprop noise.
James H. Dittmar
|Series||Technical memoranda / National Aeronautics and Space Administration -- no.TM-87129|
Noise Pollution in the Laboratory Abstract The overall level of noise in a laboratory depends on a number of factors including the location of the laboratory, the materi-als used in construction of the building as well as the instrumentation and equip-ment used to carry out the tasks of the fa-. The presented study is on a laboratory scaled industrial gas turbine combustor of intensity 25MW/m 3 atm, where an open loop active control technique is investigated. Combustion noise is classified as direct and in-direct combustion noise. The present study is focused on the investigation of direct combustion noise.
Chapter The Advanced Turboprop Project: Radical Innovation in a Conservative Environment. by Mark D. Bowles and Virginia P. Dawson. In , a Washington Post headline read, "The aircraft engine of the future has propellers on it." 1 To many this statement was something like heralding "the reincarnation of silent movies." 2 Why would an "old technology" ever be chosen over a modem, new. COVID Resources. Reliable information about the coronavirus (COVID) is available from the World Health Organization (current situation, international travel).Numerous and frequently-updated resource results are available from this ’s WebJunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus.
Advanced turboprop aircraft flyover noise annoyance to counter-rotating-propeller configurations with an equal number of blades on each rotor: preliminary results (SuDoc NAS ) [McCurdy, David A.] on *FREE* shipping on qualifying offers. Advanced turboprop aircraft flyover noise annoyance to counter-rotating-propeller configurations with an equal number of blades on each Author: David A. McCurdy. Optimization of the active control of turboprop cabin noise. Visualitza/Obre. C proof (6,Mb) Cpdf (6,Mb) Comparteix: /1.C Veure estadístiques d'ús. Mostra el registre d'ítem complet. Romeu Garbí, Jordi. Palacios, J. Balastegui Manso, Andreu.
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LABORATORY EXPERIMENTS ON ACTIVE SUPPRESSION OF ADVANCED TURBOPROP NOISE James H. Dittmar National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio SUMMARY The noise generated by supersonic tip speed propellers may be a cabin environment problem for future propeller-driven airplanes.
Get this from a library. Laboratory experiments on active suppression of advanced tuboprop noise. [James H Dittmar; Lewis Research Center.]. cooperation with the Aircraft Noise Reduction Division of the Lanqley Research Center, for plan- ning the interior noise acoustic research program for the Lewis-manaqed Advanced Turboprop Project, the author espoused a number of concepts involving SBN research, as qiven below: (1) Laboratory model tests and qround based.
noise, and almost none has been conducted for ad- vanced turboprop noise. To address this need, two laboratory experiments were conducted to quantify the annoyance of people to advanced turboprop air- craft flyover noise.
The primary concern in quantifying advanced tur- boprop noise annoyance is the unique spectral char. Journal Sound and Vibration () (1), ADVANCED TURBOPROP NOISE PREDICTION BASED ON RECENT THEORETICAL RESULTS F.
FARASSAT AND S. PADULA NASA Langley Research Center, Hampton, VirginiaU.S.A. AND M. DUNN PRC Kentron International, Inc., Hampton, Virginia,U.S.A. (Received 10 Juneand in revised form 29 Cited by: We present some fly-over noise data.
The data include measurements by 13 microphones at community locations, meteorological data, and flight recorder data packs, which provide the complete state of the aircraft along the noise trajectory. Examples of verification are shown for the turboprop airplane Dash8-Q, both on approach and departure.
Two experiments were conducted to quantify the annoyance of people to the flyover noise of advanced turboprop aircraft with counter‐rotating propellers (CRP). The objectives were: (1) determine the effects of tonal content on annoyance; and (2) compare annoyance to advanced turboprop aircraft with annoyance to conventional turboprop and jet aircraft.
A laboratory experiment was conducted to compare the annoyance to advanced turboprop aircraft flyover noise with the annoyance to conventional turboprop and jet aircraft flyover noise.
The effects of fundamental frequency and tone‐to‐broadband noise ratio on advanced turboprop annoyance were also examined.
A computer synthesis system was used to generate 18 realistic, time. Cabin noise in turboprop aircraft causes passenger discomfort, airframe fatigue, and employee scheduling constraints due to OSHA standards for exposure to high levels of noise.
The noise levels in the cabins of turboprop aircraft are typically 10 to 30 decibels louder than commercial jet noise levels. However, unlike jet noise the turboprop noise spectrum is dominated by a few low frequency.
 Emborg U., “ Cabin Noise Control in the Saab High-Speed Turboprop Aircraft,” International Conference on Noise and Vibration Engineering, Univ. of. Interior noise ground tests conducted on a DC-9 aircraft test section are described.
The objectives were to study ground test and analysis techniques for evaluating the effectiveness of interior noise control treatments for advanced turboprop aircraft, and to study the sensitivity of the ground test results to changes in various test conditions.
In this paper, the power spectrum analysis method of the areoengine test noise was discussed, and the noise measurement and analysis experiments of a turboprop engine test were carried out.
The. In order to find a solution to the control of low frequency noise in the cabin of turboprop driven aircraft, an experimental active noise control (ANC) system is introduced in the paper, which consists of vibroacoustic field analogue subsystem, acoustic field measurement subsystem and acoustic barrier exciter subsystem.
Effects of both different spaces between the primary sound source and. Quantum-intensity-correlated twin beams of light can be used to measure absorption with precision beyond the classical shot-noise limit.
The degree to which this can be achieved with a given estima. Active noise control in turbofan aircrafts: theory and experiments Ernesto Monaco a, Leonardo Lecce a, Ciro Natale b, Salvatore Pirozzi b and Chris May c a Dept.
of Aerospace Engineering - University of Naples, Via Claudio, 21, Naples, Italy b Dipartimento di Ingegneria dell'Informazione - Seconda Universit a degli Studi di Napoli, Via R I Aversa (CE), Italy.
Two laboratory experiments were conducted to quantify the annoyance response of people to the fly-over noise of advanced turboprop (propfan) aircraft with counter-rotating propellers. The specifc ob-jectives were (1) to determine the effects on annoy-ance of fimdanmntal frequency (blade fre.
Abstract: This paper presents a remotely controlled educational experiments setup for Active Noise Control (ANC) and acoustic experiments. The experiments setup is based on the Virtual Instruments Systems in Reality (VISIR) open source platform, National Instruments LabVIEW software and a Digital Signal Processor TMSC from Texas Instruments.
Trained laboratory personnel must understand how chemical laboratory facilities operate. Given the chance, they should provide input to the laboratory designers to ensure that the facilities meet the needs of the functions of the laboratory.
Laboratory personnel need to understand the capabilities and limitations of the ventilation systems, environmental controls, laboratory chemical hoods. Aerogine noise leads to environment pollution largely when aerogine is tested.
In this paper, the power spectrum analysis method of the aeroengine test noise was discussed, and the noise measurement and analysis experiments of a turbojet engine and a turbofan engine tests were carried out.
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laboratory experiments have raised the question about the accuracy of results from laboratory experiments. They have also put in to question the usefulness of laboratory experiments in evaluation of the impacts of possible abatement strategies that aim to reduce the noise pollution effects on human and environmental health.Interior noise in modern turboprop aircraft is a serious problem as it is directly related to passenger comfort, crew performance, and aircraft weight.
For turboprop aircraft the most important noise sources are the propellers generating intense low‐frequency noise which is, in general, difficult to reduce by passive measures. Therefore, extensive work has been conducted on active noise.The Active Structural Acoustic Control (ASAC) technique was applied to reduce propeller-induced noise and vibration in the passenger cabin of the deHavilland Dash-8 turboprop aircraft.
Piezoceramic elements were used for structural actuation while velocity feedback of the fuselage was achieved through the use of accelerometers.