Aircraft noise

About: Aircraft noise is a research topic. Over the lifetime, 3051 publications have been published within this topic receiving 32039 citations.

An acoustical study of the XV-15 Tilt Rotor Research Aircraft

Abstract: Acoustic data were obtained during a full-scale test of the XV-15 Tilt Rotor Research Aircraft in the Ames 40- by 80-Foot Wind Tunnel. The XV-15 has two 25-ft-diameter, three-bladed rotors at the tips of a 32-ft span wing. The rotors are used as lifting rotors, as propellers, and in various intermediate stages. Acoustic waveforms, dBA, and spectra as functions of different rotor conditions are presented and discussed. The noise level was found to be sensitive to change in rotor-disk angle of attack in the helicopter configuration. Much higher noise levels and harmonic contents were found in the helicopter mode than in the airplane mode. The measurements are compared with existing theoretical predictions which include wind-tunnel wall reflections.

Non-acoustical factors in noise management at Heathrow Airport.

Abstract: Non-acoustic factors in environmental noise can be broadly defined as all those factors other than noise level alone which contribute to noise annoyance and similar effects. Noise levels such as LAeq provide a good indication of the amount of physical noise present, and changes in physical noise level can be expected to correlate with changes in resident's perception, at least to some degree. On the other hand, a flexible approach to noise management based on wide consultation and communication can be extremely important. At Heathrow Airport over the last 20 to 30 years, overall aircraft noise levels have reduced because of the phasing out of the older noisier Chapter 2 aircraft types, but there are also other strategies in place which are clearly regarded as being effective both by airport management and by local community representatives and which are not as easily quantified in terms of noise level alone. This paper describes the background to noise management at Heathrow in some detail and draws a general conclusion that taking non-acoustic factors into account in addition to physical noise levels alone has been of considerable benefit over the years.

An overview of concepts and past findings on noise events and human response to surface transport noise

Abstract: Noise events are well established in the measurement and management of aircraft noise. While there have been attempts to apply similar noise-event concepts to road and rail traffic noise signals for many decades, the idea has remained largely peripheral to the current paradigm of surface traffic noise measurement, assessment and management. The latter is based, almost exclusively, on metrics that utilize integrated energy of the traffic noise signal, or exceedance levels. This paper, as an introduction to a session that focuses on noise events from transportation noise, provides an overview of concepts and past findings on human responses of annoyance and interference with human activities, including sleep disturbance, that have been related to noise events and other pattern measures of the noise from surface traffic flows.

A Comprehensive Bibliography of Literature on Helicopter Noise Technology

Abstract: : This bibliography, covering the period 1975 through calendar 1980, also provides, abstracts on literature that appear to make a significant contribution to the field of helicopter noise technology. The helicopter is recognized as a complex noise generator, with significant contributions from the rotors, the engine and the gearbox. Progress continues to be made in the noise areas of: (a) Formulations, math models and analytical procedures; (b) Noise prediction methodology; (c) Noise reduction techniques; and (d) Subjective response to helicopter noise. The body of information, data and knowledge has use in many applications, including the reduction of helicopter noise in a cost effective manner and in minimizing annoyance to the civil populace.