Aircraft noise

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

Landing gear and cavity noise prediction

Abstract: Prediction of airframe noise radiation from the landing gear and wheel wells of commercial aircraft is examined. Measurements of these components on typical aircraft are presented and potential noise sources identified. Semiempirical expressions for the sound generation by these sources are developed from available experimental data and theoretical analyses. These expressions are employed to estimate the noise radiation from the landing gear and wheel wells for a typical aircraft and to rank order the component sources.

Noise transmission through an acoustically treated and honeycomb stiffened aircraft sidewall

Abstract: The noise transmission characteristics of test panels and acoustic treatments representative of an aircraft sidewall are experimentally investigated in the NASA Langley Research Center transmission loss apparatus. The test panels were built to represent a segment sidewall in the propeller plane of a twin-engine, turboprop light aircraft. It is shown that an advanced treatment, which uses honeycomb for structural stiffening of skin panels, has better noise transmission loss characteristics than a conventional treatment. An alternative treatment, using the concept of limp mass and vibration isolation, provides more transmission loss than the advanced treatment for the same total surface mass. Effects on transmission loss of a variety of acoustic treatment materials (acoustic blankets, septa, damping tape, and trim panels) are presented. Damping tape does not provide additional benefit when the other treatment provides a high level of damping. Window units representative of aircraft installations are shown to have low transmission loss relative to a completely treated sidewall.

Aircraft Noise Exposure and Subjective Sleep Quality: The Results of the DEBATS Study in France

Abstract: Background: Exposure to aircraft noise has been shown to have adverse effects on health, particularly on sleep. Exposure to nighttime aircraft noise clearly affects sleep architecture, as well as subjective sleep quality. Objectives: This study aimed to investigate the relationship between aircraft noise exposure and subjective sleep quality in the population living near airports in France. Methods: A total of 1,244 individuals older than 18 and living near three French airports (Paris-Charles de Gaulle, Lyon-Saint-Exupery and Toulouse-Blagnac) were randomly selected to participate in the study. Information on sleep as well as health, socioeconomic and lifestyle factors was collected by means of a face-to-face questionnaire performed at their place of residence by an interviewer. For each participant, aircraft noise exposure was estimated at home using noise maps. Logistic regression models were used with adjustment for potential confounders. Results: Aircraft noise exposure was significantly associated with a short total sleep time (TST) (£ 6 h) and with the feeling of tiredness while awakening in the morning. An increase of 10 dB(A) in aircraft noise level at night was associated with an OR of 1.63 (95%CI: 1.15-2.32) for a short TST and an OR of 1.23 (95%CI: 1.00-1.54) for the feeling of tiredness while awakening in the morning. Conclusions: These findings contribute to the overall evidence suggesting that aircraft noise exposure at nighttime may decrease the subjective amount and quality of sleep.

Large scale model measurements of airframe noise using cross-correlation techniques

Abstract: Cross-correlation techniques are used to measure the sound radiated by wing/flap airfoil configurations in the NASA-Ames 40 x 80 ft wind tunnel using a 6.7-m semispan model with three deployed flaps. The dominant source of flap noise is identified as the flap side edges, which exceeds that radiated by the midspan region by more than 10 dB. The turbulent surface eddies at the flap side edge have scales on the order of one-half the flap chord. The installation of flap actuator fairings at the flap side edge reduces the noise radiated from that location by 10 to 15 dB. The cross-correlation technique extracts airframe noise radiated by specific surface locations from the tunnel background noise, even when the noise is 25 dB higher than the measured airframe noise level.