Aircraft noise

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

Some health effects of aircraft noise with special reference to shift work.

Abstract: Background:Aircraft noise is an environmental stressor. A positive relationship exists between noise and high blood pressure. Shift work is an additional hazardous working condition with negative effect on the behavior attitude of workers.Objective:This study aimed at investigating some health hazards for shift work on workers at Cairo International Airport (CIA), Egypt, as a strategic work place, with more than one stressor.Subjects and Methods:Assessment of noise effects were carried out in four working sites at the airport besides control sites. The average noise level in the exposure sites was 106.5 dB compared with 54 dB at the control sites. The study comprised a group of 200 male workers exposed to aircraft noise and 110 male workers not exposed to noise as control group. All workers had full general medical examination after filling specially formulated questionnaire. Hearing impairment, raised blood pressure, headaches, disturbed sleep, and symptoms of anxiety were more prominent among the expose...

An acoustic sensitivity study of general aviation propellers

Abstract: This paper describes the results of a study in which a systematic approach has been taken in studying the effect of selected propeller parameters on the character and magnitude of propeller noise. Four general aviation aircraft were chosen, i.e., a Cessna 172, Cessna 210, Cessna 441, and a 19 passenger commuter concept, to provide a range in flight velocity, engine horsepower, and gross weight. The propeller parameters selected for examination consisted of number of blades, rpm reduction, thickness/chord reduction, activity factor reduction, proplets, airfoil improvement, sweep, position of maximum blade loading, and diameter reduction.

Enhanced Modeling of Aircraft Taxiway Noise—Scoping

Abstract: Aircraft taxi noise acoustic sensitivity studies were conducted to document the importance of the modeling elements within INM and AEDT: source noise, operations, and environmental propagation. Sensitivity studies decoupled the taxi noise into the three areas and exercised each element independently. Limited opportunistic commercial aircraft taxi operation acoustic measurements were conducted. Independent taxi flight data recorder (FDR) information was queried to determine statistical engine and aircraft operational parameters. The sensitivity studies revealed the primary driver for prediction is source noise: level, spectra and directivity. A nominal taxi state NPD, spectral class and directivity database is suggested based on existing data augmented with measurements. There is sufficient capability in INM to support detailed taxi operations. Future improvements planned for AEDT will reduce user input burden. The propagation algorithms, primarily lateral attenuation are sufficient. Airport-specific considerations may necessitate inclusion of terrain, shielding and variable ground impedance. The measured acoustic data and FDR data were separate; therefore one could not quantify sensitivity of taxi noise to thrust. This identifies a need for a concurrent acoustic/FDR dataset. The study suggests modeling nominal taxi state in the short term with a comprehensive long term enhanced acoustic sensitivity to thrust capability.

Aeroacoustic Imaging Experiments of Airframe Noise in Lined Wall Closed-Section Wind Tunnel

Abstract: Acoustic imaging is an indispensable experimental aid in the design of silent aircraft. In this work, acoustic imaging is performed in a classical closed-section wind tunnel that has been extensively modified using specifically designed liners on the walls of the test section. The details of the associated acoustic modification and the aeroacoustic imaging method are introduced in this paper. The acoustic test performance is carefully evaluated by examining background noise reductions and acoustic beamforming results. The experimental outcomes suggest that the proposed acoustic modification could suppress background noise by 5 dB at 40–80 m/s test flow speeds. The beamforming results clearly identify the dominant airframe noise sources at landing gears and high-lift devices. The experimental results agree fairly well with the preceding computational and empirical predictions. The proposed acoustic imaging technique has been shown to be an effective experimental technique in identifying airframe n...