Showing papers on "Aircraft noise published in 2005"

Using happiness surveys to value intangibles: the case of airport noise

Abstract: We assess the monetary value of the noise damage, caused by aircraft noise nuisance around Amsterdam Airport, as the sum of hedonic house price differentials and a residual cost component. The residual costs are assessed from a survey, including an ordinal life satisfaction scale, on which individual respondents have scored. The derived compensation scheme depends on, among other things, the objective noise level, income, the degree to which prices account for noise differences, and the presence of noise insulation.

Framework for Aircraft Conceptual Design and Environmental Performance Studies

Abstract: Although civil aircraft environmental performance has been important since the beginnings of commercial aviation, continuously increasing air traffic and a rise in public awareness have made aircraft noise and emissions two of the most pressing issues hampering commercial aviation growth today. This, in turn, has created the demand for an understanding of the impact of noise and emissions requirements on the design of the aircraft. In response, the purpose of this research is to explore the feasibility of integrating noise and emissions as optimization objectives at the aircraft conceptual design stage, thereby allowing a quantitative analysis of the tradeoffs between environmental performance and operating cost. A preliminary design tool that uses a multiobjective genetic algorithm to determine optimal aircraft configurations and to estimate the sensitivities between the conflicting objectives of low noise, low emissions, and operating costs was developed. Beyond evaluating the ability of a design to meet regulations and establishing environmental performance trades, the multidisciplinary design tool allows the generation of conventional but extremely low-noise and low-emissions designs that could, in the future, dramatically decrease the environmental impact of commercial aviation, albeit at the expense of increased operating cost. The tool incorporates ANOPP, a noise prediction code developed at NASA Langley Research Center, NASA Glenn Research Center's Engine Performance Program engine simulator, and aircraft design, analysis, and optimization modules developed at Stanford University. The trend that emerges from this research among the seemingly conflicting objectives of noise, fuel consumption, and NO x emissions is the opportunity for significant reductions in environmental impact by designing the aircraft to fly slower and at lower altitude.

Paying for quietness : the impact of noise on Geneva rents

Abstract: Using the hedonic approach, this paper analyses housing market data to infer the impact of noise on rents in Geneva, Switzerland. Using three different databases, including a geographical information system (GIS), structural, accessibility and environmental variables were obtained for a large proportion of apartments rented in Geneva. The paper is thus in line with the new generation hedonic models, which exploit the vast potential of GIS to obtain large databases including detailed characteristics of the apartments. In addition, different and original measures of noise were used in order to assess possible differences of the noise impact on rents, while existing studies typically refer to a single noise index. This paper assesses the impacts of noise related to all sources, but also to airport noise only, while existing studies usually refer to road or aircraft noise. The results can be summarised as follows. First, it is shown that the impact of all sources of noise on rents at the level of the whole ca...

Hypertension and Exposure to Noise near Airports (HYENA): study design and noise exposure assessment.

Abstract: An increasing number of people live near airports with considerable noise and air pollution. The Hypertension and Exposure to Noise near Airports (HYENA) project aims to assess the impact of airport-related noise exposure on blood pressure (BP) and cardiovascular disease using a cross-sectional study design. We selected 6,000 persons (45–70 years of age) who had lived at least 5 years near one of six major European airports. We used modeled aircraft noise contours, aiming to maximize exposure contrast. Automated BP instruments are used to reduce observer error. We designed a standardized questionnaire to collect data on annoyance, noise disturbance, and major confounders. Cortisol in saliva was collected in a subsample of the study population (n = 500) stratified by noise exposure level. To investigate short-term noise effects on BP and possible effects on nighttime BP dipping, we measured 24-hr BP and assessed continuous night noise in another sub-sample (n = 200). To ensure comparability between countries, we used common noise models to assess individual noise exposure, with a resolution of 1 dB(A). Modifiers of individual exposure, such as the orientation of living and bedroom toward roads, window-opening habits, and sound insulation, were assessed by the questionnaire. For four airports, we estimated exposure to air pollution to explore modifying effects of air pollution on cardiovascular disease. The project assesses exposure to traffic-related air pollutants, primarily using data from another project funded by the European Union (APMoSPHERE, Air Pollution Modelling for Support to Policy on Health and Environmental Risks in Europe).

Effects of Nocturnal Aircraft Noise on Sleep Structure

Abstract: Question of the study To systematically investigate the influence of nocturnal aircraft noise on sleep structure.

Generic and site-specific criteria in the optimization of noise abatement trajectories

Abstract: This paper presents a trade-off study that has been conducted using a recently developed tool for the analysis and design of noise abatement procedures around airports. This new tool, NOISHHH, combines a noise model, a geographic information system, and a dynamic trajectory optimization algorithm. NOISHHH features a multi-objective optimization capability that permits exploration of a variety of environmental criteria, including indices that are generic in nature (e.g. noise footprints) as well as site-specific criteria that take into account the population distribution in the areas surrounding the airport. Using this capability a noise performance trade-off was conducted by comparing arrival trajectories that are optimized according to a variety of noise abatement criteria, including both generic and site-specific criteria. The main focus is on providing insight into the sensitivities in the multi-objective noise performance trade-off process. The results are used to illustrate the possibility of synthesizing trajectories that provide a sensible compromise solution among the various noise criteria.

Engine And Installation Configurations For A Silent Aircraft

Abstract: The Silent Aircraft Initiative is a research projec t funded by the Cambridge-MIT Institute aimed at reducing aircraft noise to the point where it is imperceptible in the urban environments around airp orts. The aircraft that fulfils this objective must also be economically competitive with conventional aircraft of the future and therefore fuel consumption is a key consideration for the design. This paper identifies some key features of a propulsion system that can achiev e the Silent Aircraft noise target and explores the relat ionships between the factors that affect fuel consumption. I t also considers the different demands made of an engine a t different operating conditions in the flight envelo pe. These studies are used to propose viable engine and installation configurations that could meet the Sil ent Aircraft noise requirements. The findings point tow ards a multiple turbofan system with a variable geometry exhaust and a novel, embedded installation.

Synthesis of Virtual Environments for Aircraft Community Noise Impact Studies

Abstract: A new capability has been developed for the creation of virtual environments for the study of aircraft community noise. It is applicable for use with both recorded and synthesized aircraft noise. When using synthesized noise, a three-stage process is adopted involving non-real-time prediction and synthesis stages followed by a real-time rendering stage. Included in the prediction-based source noise synthesis are temporal variations associated with changes in operational state, and low frequency fluctuations that are present under all operating conditions. Included in the rendering stage are the effects of spreading loss, absolute delay, atmospheric absorption, ground reflections, and binaural filtering. Results of prediction, synthesis and rendering stages are presented.

Performance assessment for airport noise charge policies and airline network adjustment response

Abstract: Noise charges have been introduced at major airports to mitigate external noise. This research investigated airline network design, by considering aircraft noise charges, and analyzing the performance of airport noise charge policies, from multiple perspectives. We formulated an airline network design model for minimizing airline operating costs, to determine optimal air routes and flight frequencies, as well as types of aircraft, in response to airport noise charges. We further assessed the performance of different noise charge policies by evaluating changes in airport operating profits and the social cost to residents surrounding the airport. An empirical example, using the Chiang Kai-Shek International Airport, illustrates how airports should determine optimal noise charge policies, from different perspectives. The results show that airlines may adjust types of aircraft, flight frequencies and flight routes, in response to hub airport noise charge policies, which may lead to changes in social costs, airport revenues, and weekly aircraft schedules. Landing fees setting may, in addition, affect the control an airport has over social costs, due to noise surcharges.

Airbus A319 Database from Dedicated Flyover Measurements to Investigate Noise Abatement Procedures

Abstract: A series of flyover noise tests on the Airbus A319 performed in the framework of the German project ”Noise Optimized Approach and Departure Procedures (LAnAb)” took place at Parchim airport (Germany) in June 2004. A noise database was created that will be a support for the validation of aircraft noise prediction models dedicated to investigate noise abatement procedures. In all, 37 take-off and 82 approach conditions were simulated. Depending on the simulated flight phase, different values of engine power, airspeed, position of the high-lift devices, and also of the landing gears were tested. The aim of this paper is to show the different possibilities of using the signals recorded by a phased-array of microphones installed on the ground to analyse aircraft noise and confront some prediction models to the results.

Aircraft noise and methods for the study of community health and well-being

Abstract: Aircraft noise potentially disturbs (or annoys) the daily activities (such as communication and relaxation) of residents living in the vicinity of airports. This particular type of annoyance undermines quality of life and can be a cause of stress. Evidence is emerging that appears to associate some forms of health risk with this stress. This research aims at developing a better understanding of the impacts of aircraft noise on community health and well-being. This paper presents the results of exploratory data analysis from a pilot survey and a social survey of 704 residents' responses (47% response rate) in Sydney that include people living close to the airport and a matched control group (not affected by aircraft noise). The paper also describes the development of a new noise metric, which has been termed the Noise Gap Index (NGI), to incorporate other background environmental noise and to describe and assess the impacts of aircraft noise on the health and well-being of residents.

Annoyance with aircraft noise in local recreational areas and the recreationists' noise situation at home.

Abstract: Few socioacoustic studies have examined the effect of noise on outdoor recreationists. Most studies concentrate on one setting of the everyday life of a noise-exposed population, which mainly has been the residential setting. This article relates annoyance with aircraft noise in outdoor recreational areas to the recreationists’ noise situation at home. In conjunction with the relocation of the main airport of Norway in 1998, field studies were conducted before and after the change in one area near the old airport (1930 survey respondents), and one area near the new airport (1001 survey respondents). Multivariate linear regression analyses of the relationship between annoyance and aircraft noise exposure (LAeq for the aircraft events) in the recreational areas were conducted, controlled for noise annoyance at home, or aircraft noise exposure at home, the situation (before/after the change), context- and demographic variables. People more highly annoyed at home tended to be more annoyed than others while in...

Aircraft noise management through controlled-area demarcation in South Africa: Its application at Cape Town International airport

Abstract: Aircraft noise is a growing social, technical, economic and environmental problem, especially in developing countries like South Africa. It arises from the growth in air traffic, urbanization, uncoordinated planning around airports, and open-window living that makes physical insulation an ineffective mitigating solution. Cape Town International airport is a typical South African example of the phenomenon. Air traffic volume is steadily increasing and an additional runway has been proposed for the airport's efficient operation. The changing noise pattern requires the demarcation of a 'noise-controlled area' around the airport as the planning framework that is legally prescribed to manage this type of environmental nuisance. This paper reports the application of geographic information system (GIS) technology to define a control zone using various spatial demarcation techniques. Each alternative zone has different spatial characteristics that define and incorporate the adjacent residential communities affected as well as vulnerable land in the vicinity. An aircraft noise generation model was used to map noise intensity contours. Different spatial noise footprints for six optional demarcation criteria were used to identify affected areas around the airport. The GIS methods were then compared and evaluated to select the optimum planning approach under South African conditions.

Environmental noise, annoyance and sleep disturbance

Abstract: Summary A rough estimate of the number of people in the EU exposed to environmental noise (from road traffic, railway traffic and aircraft) above a day-evening-night-level of 55 dB(A) is 150 million (40 per cent), including about 120 million people exposed to road traffic noise. Adverse environmental noise-induced health effects mainly are annoyance, sleep disturbance, stress-related somatic effects, effects on learning in children, and possibly hearing damage. These effects occur in a substantial part of the EU population. In this chapter the relationships between annoyance and noise exposure to various types of environmental noise are given. With respect to sleep disturbance, this chapter discusses effects of night time noise on motility (motoric unrest), self-reported sleep disturbance, and self-assessed awakening.

Installation Effects on the Flow and Noise of an Under-the-Wing Mounted Dual Stream Jet

Abstract: It is known experimentally that a jet mounted under a wing generates more noise than the same jet in isolation. The excess noise is referred to as installation noise. Installation noise is largely of aerodynamic origin. The principal mechanism is believed to be the impact of the downwash of the wing-flap on the jet flow. The downwash causes the jet to deflect downward and to distort laterally. This brings about an increase in turbulence in the jet. The increase in the level of turbulence, in turn, leads to the emission of additional noise. The modeling and computation of the downwash, the distorted jet flow and the excess noise radiation are the objectives of this investigation. It will be shown that calculated results at high frequencies compare well with experimental measurements. I. Introduction T is known experimentally, since the late seventies, that a jet installed under a wing of an aircraft radiates more noise than the same jet in a stand-alone condition. The excess noise is the propulsion-airframe integration noise or commonly referred to as installation noise. When a jet is placed near a wing, there is an increase in noise in the flyover directions because of the reflection of sound by the wing. Here, installation noise includes not merely the noise increase due to the reflection of sound by the wing. The major part of this noise is generated aerodynamically by the nonlinear interaction between the flow around the wing-flap and the jet. In this work, our primary interest is to model and to predict installation noise of aerodynamic origin. Installation noise increases not only the total aircraft noise in the fly-over plane but also in the sideline directions. It is especially important during landings and take-offs when the flaps are down. During the eighties, a number of experiments were carried out trying to quantify the characteristics and intensity of installation noise

The Effect of Bypass Nozzle Exit Area on Fan Aerodynamic Performance and Noise in a Model Turbofan Simulator

Abstract: The design of effective new technologies to reduce aircraft propulsion noise is dependent on identifying and understanding the noise sources and noise generation mechanisms in the modern turbofan engine, as well as determining their contribution to the overall aircraft noise signature. Therefore, a comprehensive aeroacoustic wind tunnel test program was conducted called the Fan Broadband Source Diagnostic Test as part of the NASA Quiet Aircraft Technology program. The test was performed in the anechoic NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel using a 1/5 scale model turbofan simulator which represented a current generation, medium pressure ratio, high bypass turbofan aircraft engine. The investigation focused on simulating in model scale only the bypass section of the turbofan engine. The test objectives were to: identify the noise sources within the model and determine their noise level; investigate several component design technologies by determining their impact on the aerodynamic and acoustic performance of the fan stage; and conduct detailed flow diagnostics within the fan flow field to characterize the physics of the noise generation mechanisms in a turbofan model. This report discusses results obtained for one aspect of the Source Diagnostic Test that investigated the effect of the bypass or fan nozzle exit area on the bypass stage aerodynamic performance, specifically the fan and outlet guide vanes or stators, as well as the farfield acoustic noise level. The aerodynamic performance, farfield acoustics, and Laser Doppler Velocimeter flow diagnostic results are presented for the fan and four different fixed-area bypass nozzle configurations. The nozzles simulated fixed engine operating lines and encompassed the fan stage operating envelope from near stall to cruise. One nozzle was selected as a baseline reference, representing the nozzle area which would achieve the design point operating conditions and fan stage performance. The total area change from the smallest to the largest nozzle was 12.9 percent of the baseline nozzle area. The results will show that there are significant changes in aerodynamic performance and farfield acoustics as the fan nozzle area is increased. The weight flow through the fan model increased between 7 and 9 percent, the fan and stage pressure dropped between 8 and 10 percent, and the adiabatic efficiency increased between 2 and 3 percent--the magnitude of the change dependent on the fan speed. Results from force balance measurements of fan and outlet guide vane thrust will show that as the nozzle exit area is increased the combined thrust of the fan and outlet guide vanes together also increases, between 2 and 3.5 percent, mainly due to the increase in lift from the outlet guide vanes. In terms of farfield acoustics, the overall sound power level produced by the fan stage dropped nearly linearly between 1 dB at takeoff condition and 3.5 dB at approach condition, mainly due to a decrease in the broadband noise levels. Finally, fan swirl angle survey and Laser Doppler Velocimeter mean velocity and turbulence data obtained in the fan wake will show that the swirl angles and turbulence levels within the wake decrease as the fan nozzle area increases, which helps to explain the drop in the fan broadband noise at all fan speeds.

Active noise control system for aircraft, and method for enhancing pilot situational awareness

Abstract: An active noise control system for aircraft includes a headset for use by a pilot of the aircraft. A plurality of sensors are mounted on the aircraft at predetermined locations to sense aircraft noise. The aircraft noise at each of the sensors has a first sound waveform in a first phase. A plurality of actuators are operatively connected to respective sensors and communicate with the headset. Each actuator generates a second sound waveform in a second phase. A controller commands each of the plurality of actuators, and dictates the second phase of the second sound waveform, such that the first and second sound waveforms interact out of phase in a manner sufficient to control the aircraft noise. The controlled aircraft noise enables auditory detection of remote environmental disturbances outside of the aircraft thereby enhancing pilot sensory awareness.

The Generation and Detection of Sound Emitted by Aircraft Wake Vortices in Ground Effect

Abstract: Sound recorded by the author in March 2002 at JFK International Airport shows that wake vortices in ground effect emit infrasound that is 1) more than 40 dB stronger than audible wake vortex sound; 2) substantially stronger than the infrasound component of wind noise and airport noise; and 3) comparable to, and often stronger than, the infrasound component of aircraft noise. Spectra and time plots of the magnitude of wake-vortex-generated sound are presented for aircraft landing on JFK runway 31R.

Flow and Noise Investigations of a Separate Flow Exhaust System

Abstract: A major component of aircraft noise is the jet noise created by the high velocity hot stream exhausting from a jet engine, interacting with itself and with the surrounding cold air. In the present ...

Addressing the noise from U.S. transportation systems: measures and countermeasures

Abstract: When transportation noise is loud enough and frequent enough, it diminishes the quality of life. This article examines the sound levels produced by common transportation sources, including aircraft, trucks, automobiles, and rail vehicles, and discusses the measures, the impacts, and the countermeasures for the noise produced by each of these modes.

Applying neural networks and geographical information systems to airport noise evaluation

Abstract: The assessment of aircraft noise is becoming an increasingly important task in ensuring sustainable airport development. Aircraft noise is influenced by many complex factors and traditional laboratory models are not sufficient to assess the exposure to noisy flights of specific local communities in proximity to an airport. In this paper neural network and fuzzy set methods have been integrated with Geographical Information Systems to provide an alternative method to evaluate airport noise.

A Study on the Assessment Method of Noise Exposure Population Using the Over-ride Value Noise Map

Abstract: Noise map is a presentation of existing data or predicted noise situation in terms of noise indicator. However, it has shortcoming for assessing the number of people exposed, or the number of dwellings affected to any relevant limit values of noise level in certain areas. In this study, so called over-ride value noise mapping is Proposed to make up for the shortcoming by using over-ride function of object-oriented programming and it is to show the guard of the area where it is satisfied the standard of option, or it is not satisfactory. Over-ride value noise map data is combined with topography layer, population and house statistics, and GIS space statistical analysis. The over-ride value noise mapping can also be applied to make the road traffic noise map, the railroad noise map, the aircraft noise map, and the industrial site noise map. This can express noise damage information more exactly.

A pragmatic re‐analysis of sleep disturbance data

Abstract: The acoustics literature documents several field studies in which aircraft noise was measured in people’s bedrooms while their awakening response was simultaneously monitored. Nearly all the studies produced a dose‐response relationship between a single event noise metric and an awakening response. Virtually all of these dose‐response relationships pertain to (1) the indoor noise dose produced by a single aircraft flyover and (2) the chances that the noise dose will awaken an average person. These dose‐response relationships are too limited for application to a full night of operations and to a realistic population of varying individual sensitivities to awakening. Accounting for multiple aircraft during the night is obviously necessary. Less obvious, but important is the need to account for person‐to‐person variation in awakening sensitivity to noise. This paper presents a re‐analysis of original data from one of the field studies. The re‐analysis generalizes the dose‐response relationships for behavioral...

Evaluation of Noise Effects in Auditory Function in Spanish Military Pilots

Abstract: : Military pilots are particularly exposed to a wide variety of environmental stresses, one of which is the noise produced by the aircraft used for flying duties. In addition to aircraft noise, changes in cabin pressure and vibration can be considered as contributing factors. Adverse effects can be produced under several situations, through exposure to noise in the flight line or during taxi, take off, or cruise operations. The environmental stress of noise can be partially attenuated through the use of noise reduction devices, but their effectiveness is still far from providing complete protection. As a consequence, limitations in speech communication and eventually hearing impairment or loss can result. This study investigates the incidence of noise-induced hearing loss in three groups of pilots belonging to the Spanish Armed Forces: fighter pilots, transport pilots, and helicopter pilots. The results show that hearing loss in pilots should be considered an occupational disease linked to noise production, repeated barotraumas, and low-frequency vibrations. The lack of adequate hearing protection leads to hearing loss, and prevention is a key factor in stopping auditory impairment. The authors hope that this data will lead them to corrective measures that will stop the adverse effects of noise on military pilots.