Written in EnglishRead online
|Statement||J.R. Mahan and C.R. Fuller.|
|Series||NASA contractor report -- 172517., NASA contractor report -- NASA CR-172517.|
|Contributions||Fuller, C. R., United States. National Aeronautics and Space Administration.|
|The Physical Object|
Download An improved source model for aircraft interior noise studies
Get this from a library. An improved source model for aircraft interior noise studies. [J R Mahan; C R Fuller; United States. National Aeronautics and Space Administration.]. An existing analytical model for noise transmission into aircraft cabins was utilized to investigate the behavior of an improved propeller source model for use in aircraft interior noise studies.
The new An improved source model for aircraft interior noise studies book model, a virtually rotating dipole, is shown to adequately match measured fuselage sound pressure distributions, including the correct Cited by: 6.
For example, studies have shown that interior aircraft noise affects pilot performance, but the potential cumulative effects of such noise have yet to be examined. The present study examined the cumulative influence of the interior noise of a light, propeller-driven, single-piston engine aircraft on operation-related performance of 14 civil Cited by: 1.
Aircraft Noise Model Validation Study January Report Page iii HARRIS MILLER MILLER & HANSON INC. G:\PROJECTS\NPS\GRANDCAN\4_MODVAL\Report\Final Rpt\Jan03\ ACKNOWLEDGEMENTS It is difficult to acknowledge all the individuals who contributed to the development, implementation and documentation of this study.
While designing an aircraft, we can predict noise levels through numerical analysis and model tests. However, the properties and characteristics of actual aircraft noise can only be obtained by actual flight tests.
Noise source localization through acoustic beamforming is a powerful tool to accomplish this. Journal of Aircraft Vol. 19, No. 1 January Analytical study of interior noise control by fuselage design techniques on high-speed propeller-driven aircraft J.
REVELL. The noise levels produced by modern aircraft are about 22 dB lower than those of ﬁrst generation jet aircraft. This reduction has been achieved as a result of the development of turbofan engines with high bypass ratios, liner technology and turbomachinery source noise reduction.
Further aircraft noise reduction will be achieved from improved. model-scale jet noise. Another aeroacoustics-related ESM study is that of Hol who applied ring-like equivalent sources to the sound radiation from engine ducts.
In developing an ESM for high-power military jet aircraft noise, one must consider the various source characteristics that should guide the development of a model. Based on the outcome of a workshop on aviation noise, this special issue on aircraft noise generation and assessment has been assembled.
Invited contributions on preselected topics have been combined into one overall story line about both the aircraft noise generation and its assessment to provide an overview on the state-of-the-art capabilities in this research field (accounting both for.
– Baseline current Air Force/Navy operational aircraft vibration and noise environments both cockpit and ground support/maintenance – Measure vibration and noise from F engine in F – Initiate human exposure effects expansion of limits and/or mitigation studies if required – Measure vibration and noise on JSF CDA variants.
Noise can be reduced at the source (using mufflers, quieter engines, electric motors), along the path of propagation (distance, barriers), or at the receiver (enclosures, better windows, earplugs).
In the case of RC aircraft, the noise source is elevated and moving, so an enclosure or a property-line noise barrier is typically not an option. Previous studies have shown that the impact of interior aircraft noise on pilot performance was not unambiguous, neither there was any unanimous methodology used for measuring it.
Results from a light aircraft demonstration program are considered which indicates that about 5 dB reduction of flyover noise can be obtained without significant performance penalty.
Sidewall design studies are examined for interior noise control in light general aviation aircraft and in large transports using propfan propulsion. This paper is mainly focused on the control strategies explored in the last decade for aircraft airframe noise reduction.
Details of the airframe noise mechanism and the noise numerical predictions can be found in the review by Dobrzynski 11 summarising the airframe noise research achievements worldwide in the last 40 years.
We first briefly summarise the noise mechanisms of. For these rooms and this rattle noise source, the rattle noise tends to increase the total interior PL by 10 dB on average. Based on this result, some of the rattle sound amplitudes for the current study were chosen so the interior PL would increase by.
The effects of cabin noise on subjective comfort assessments were systematically investigated in order to reveal optimisation potentials for an improved passenger noise acceptance. Two aircraft simulation studies were conducted.
An acoustic laboratory test facility provided with loudspeaker systems for realistic sound presentations and an. This dissertation investigates the noise due to an en-route aircraft cruising at high altitudes. It offers an improved understanding into the combined effects of atmospheric propagation, ground reflection, and source motion on the impact of en-route aircraft noise.
A numerical model has been developed to compute pressure time-histories due to a uniformly moving source above a flat ground. CHAPTER 6 AIRCRAFT NOISE ANALYSIS 6‐2 Spokane International Airport Master Plan (March ) The strength, or loudness, of a sound wave is measured using decibels on a logarithmic scale.
The range of audibility of a human ear is 0 dB (threshold of hearing) to dB (pain begins). Since passengers on existing turbofan aircraft have become accustomed to lower interior noise than exists in current propeller aircraft, there has been a renewed interest in interior noise control by reduction of propeller source noise, by design of lightweight fuselage soundproofing and other noise reduction concepts.
BeBeC TOOL FOR INTERIOR NOISE SOURCES DETECTION IN AIRCRAFT WITH COMPARISON OF CONFIGURATIONS. Charles Cariou1, Osmin Delverdier1, Sébastien Paillasseur2 and Lucille Lamotte2.
1Airbus, Flight & Integration Tests. suppression of aircraft to improve the habitability of the cabin. INTRODUCTION Cabin noise in turbo-propeller driver aircraft can cause crew and passenger discomfort.
The noise level in the interior of turbopropeller-driven aircraft, which results mainly from the excitation of the fuselage by the.
This paper describes experimental and analytical studies of the interior noise of twin-engine, propeller-driven, light aircraft. Experimental results indicate that interior noise levels due to propeller noise can be reduced by reduction of engine rpm at constant airspeed (about 3 dB), by synchronization of the twin engines/propellers (up to 12 dB), and by increasing the distances from.
In tactical aircraft, a primary noise source is the high air flow velocities associated with cooling the avionics. Noise of flight lines Flight lines include noise environments that are typically well above double hearing protection requirements (Yankaskas and Komrower, Research Center under NASA Research Grant NAG entitled, “General Aviation Interior Noise Source Identification Technology Research,” NLPN The authors wish to acknowledge the contribution of the Cessna Aircraft Company, Single-Engine Division who supplied the Model E and Model test aircraft and fully supported.
Aircraft noise also affects people within the aircraft: crew and passengers. Cabin noise can be studied to address the occupational exposure and the health and safety of pilots and flight attendants. In64 commercial airline pilots were surveyed regarding hearing loss and tinnitus. Inthe NIOSH conducted several noise surveys and health hazard evaluations, and found noise levels.
Research Center under Research Grant NAG entitled "General Aviation Interior Noise Source Identification Technology Research,” NLPN The authors wish to acknowledge the contribution of the Cessna Aircraft Company, Single-Engine Division who so graciously supplied the Model E test aircraft and fully supported the.
• Identify parts of model where improved • Construct research roadmap that will improve understanding. 3 Initial model for aircraft noise-induced sleep disturbance Non-acoustic factors Acoustic factors Sleep disturbance •Culture •Age • Data and results from available studies of noise.
receiver, and sometimes the source. If noise cannot be controlled to an acceptable level at the source, attempts should then be made to control it at some point during its propagation path; that is, the path along which the sound energy from the source travels.
In. Aircraft noise, however, is an intermittent noise, and therefore the SI literature is inadequate with respect to intermittent noise (the EPA levels document briefly addresses the issue of intermittent noise). There is a need for more research on the effect of intermittent noise, such as an aircraft.
The acoustic model can be used to design a new aircraft, evaluate new engines for existing aircraft, or evaluate other low-frequency noise problems. An acoustic model can be coupled to and excited.
control realistic interior noise levels. The ASAC system was tested with a realistic engine disturbance and the results demonstrated that ASAC will work in realistic aircraft systems. (2) Active trim panels for interior noise reduction The fuselage experimental rig was modified to implement three exterior uncorrealated noise sources.
confounders in these noise and health studies. In assessing relevant exposures, it is rare that an observed effect is clearly and solely attributable to the noise source of interest, as total noise exposure (in work, while commuting, at home or elsewhere in the community) is rarely assessed.
Further, the actual exposure inside. annoyed by aircraft noise at given noise levels indicates a general increase of aircraft noise annoyance over time, cannot be answered here due to lack of published data.
For instance, most of the studies containing exposure-response data report %HA vs. L pAeq, and skip mean annoyance vs. L pAeq or other acoustical exposure descriptors. In order to determine whether exposure to aircraft interior noise is a health hazard, sound samples were taken in two types of aircraft: a Cessna and a Piper PA Seminole.
Community fear of aircraft crashes is closely associated with noise. Horonjeff, in his Planning and Design of Airports 6 indicates that reduction of aircraft noise reduces the number of complaints regarding airport operation and that fears of low-flying aircraft and of property devaluation, an indirect measure of nuisance and hazard, are both associated with noise.
Interior noise: cabin & cockpit A/C: Ramp noise JCAB Visit - Aircraft Noise - Technologies and Operations Improved aerodynamic performance Sharklets Air Flow Deflectors Cavity noise Aircraft Noise - Technologies and Operations July Low noise.
TRB’s Airport Cooperative Research Program (ACRP) Synthesis 9: Effects of Aircraft Noise: Research Update on Select Topics includes an annotated bibliography and summary of new research on the effects of aircraft noise.
The report is designed to update and complement the U.S. Federal Aviation Administration’s Aviation Noise Effects report. This article provides a current knowledge base of adverse effects due to community and occupational low frequency noise (20– Hz).
Low frequency noise has a large annoyance potential, and the. the last 30 years in attempts to reduce and abate aircraft noise impacts. The current Federal Aviation Administration (FAA) emphasis on land use compatibil ity studies is noted.
An overview and simple sensitivity analysis of the pri mary airport noise analysis tool--the FAA' s Integrated Noise Model (INM), is. An important pillar of the Balanced Approach to Aircraft Noise Management is the reduction of noise at source.
Aircraft noise ("noise at source") has been controlled since the s by the setting of noise limits for aircraft in the form Standards and Recommended Practices (SARPs) contained in Annex 16 to the Convention on International Civil Aviation (the "Chicago Convention").
The following is an excerpt from Appendix A of Findings of the Low-Frequency Noise Expert Panel of the Richfield-MAC Noise Mitigation Agreement of 17 DecemberAnnotated, Sept.
30, The red italic type is text added after the final report was issued May 9,and was intended by the authors to indicate whether consensus had been reached on significant points.
The survey sample classified aircraft noise as the most objectionable source of noise (18, 19, e12): the higher the aircraft noise level, the greater was the annoyance (figure 4). Figure 4 Proportion of persons exposed to serious aircraft noise annoyance as a factor of continuous daytime noise level (L eq, 16 h) calculated by the % rule (19).(c) Relative humidity and ambient temperature over the whole noise path between a point 33 ft (10 m) above the ground and the airplane such that the sound attenuation in the one-third octave band centered on 8 kHz will not be more than 12 dB/ m unless: (1) The dew point and dry bulb temperatures are measured with a device which is accurate to ± °F (± °C) and used to obtain.