Showing papers on "Aircraft noise published in 2010"

Almost 40 Years of Airframe Noise Research: What Did We Achieve?

Abstract: With the advent of low noise high bypass ratio turbofan engines airframe noise gained significant importance with respect to the overall aircraft noise impact around airports. Already around 1970 airframe noise, originating from flow around the landing gears and high-lift devices, was recognized as a potential “lower aircraft noise barrier” at approach and landing. Since then, the outcome of extensive acoustic flight tests and aeroacoustic wind tunnel experiments enabled a detailed description and ranking of the major airframe noise sources and the development of noise reduction means. In the last decade advances in numerical and experimental tools led to a better understanding of complex noise source mechanisms. Efficient noise reduction technologies were developed for landing gears while the benefits of high-lift noise reduction means were often compensated by a simultaneous degradation in aerodynamic performance. The focus of this paper is not on the historical sequence of airframe noise research but rather aims to provide a concise survey of the achievements in airframe noise source description and reduction over the last 40 years worldwide. Due to the vast amount of work focused on a variety of airframe noise problems, this review can only provide examples but does not claim to be complete.

The associations between noise sensitivity, reported physical and mental health, perceived environmental quality, and noise annoyance

Abstract: One hundred and ninety residents around Frankfurt Airport (46% female; 17-80 years) were interviewed concerning noise annoyance due to transportation noise (aircraft, road traffic), perceived mental and physical health, perceived environmental quality, and noise sensitivity. The aim of the analyses was to test whether noise sensitivity reflects partly general environmental sensitivity and is associated with an elevated susceptibility for the perception of mental and physical health. In this study, the reported physical and mental health variables were not associated with noise exposure but with noise annoyance, and were interpreted to reflect nonspecific codeterminants of annoyance rather than noise effects. Noise sensitivity was found to influence total noise annoyance and aircraft noise annoyance but to a lesser degree annoyance due to road traffic noise. Noise sensitivity was associated with reported physical health, but not with reported mental health. Noise-sensitive persons reported poorer environmental quality in their residential area than less sensitive persons in particular with regard to air traffic (including the facets noise, pollution, and contaminations) and quietness. Other aspects of the perceived quality of the environment were scarcely associated with noise sensitivity. This indicates that noise sensitivity is more specific and a reliable predictor of responses to noise from the dominant source (in this case air traffic) rather than a predictor of the individual perception of the environmental quality in general.

Aircraft Noise and Quality of Life around Frankfurt Airport

Abstract: In a survey of 2,312 residents living near Frankfurt Airport aircraft noise annoyance and disturbances as well as environmental (EQoL) and health-related quality of life (HQoL) were assessed and compared with data on exposure due to aircraft, road traffic, and railway noise. Results indicate higher noise annoyance than predicted from general exposure-response curves. Beside aircraft sound levels source-related attitudes were associated with reactions to aircraft noise. Furthermore, aircraft noise affected EQoL in general, although to a much smaller extent. HQoL was associated with aircraft noise annoyance, noise sensitivity and partly with aircraft noise exposure, in particular in the subgroup of multimorbid residents. The results suggest a recursive relationship between noise and health, yet this cannot be tested in cross-sectional studies. Longitudinal studies would be recommendable to get more insight in the causal paths underlying the noise-health relationship.

Multi-objective optimisation for aircraft departure trajectories minimising noise annoyance

Abstract: This paper presents a strategy for designing noise abatement procedures aimed at reducing the global annoyance perceived by the population living around the airports. A non-linear multi-objective optimal control problem is implemented and numerically solved obtaining minimal annoyance trajectories. Annoyance criteria are treated as non-linear functions that can be obtained by using fuzzy logic modelling techniques. Here, a basic implementation is shown where the annoyance is expressed in function of the maximum perceived noise level, the period of the day when the trajectory takes place and the type of area over-flown. Then, lexicographic optimisation techniques are used to deal with the multi-criteria nature of the problem. Finally, an illustrative example is given concerning a hypothetical scenario with five different noise sensitive locations and where different optimal trajectories are obtained for different hours of the day.

Prediction of Broadband Shock-Associated Noise Using Reynolds-Averaged Navier-Stokes Computational Fluid Dynamics

Abstract: Broadband shock-associated noise is a component of jet noise generated by supersonic jets operating offdesign. It is characterized by multiple broadband peaks and dominates the total noise at large angles to the jet downstream axis. A new model is introduced for the prediction of broadband shock-associated noise that uses the solution of the Reynolds-averaged Navier-Stokes equations. The noise model is an acoustic analogy based on the linearized Euler equations. The equivalent source terms depend on the product of the fluctuations associated with the jet's shock-cell structure and the turbulent velocity fluctuations in the jet shear layer. The former are deterministic and are obtained from the Reynolds-averaged Navier-Stokes solution. A statistical model is introduced to describe the properties of the turbulence. Only the geometry and operating conditions of the nozzle need to be known to make noise predictions. This overcomes the limitations and empiricism present in previous broadband shock-associated noise models. Results for various axisymmetric circular nozzles and a rectangular nozzle operating at various conditions are compared with experimental data to validate the model.

Night time aircraft noise exposure and children's cognitive performance

Abstract: Chronic aircraft noise exposure in children is associated with impairment of reading and long-term memory. Most studies have not differentiated between day or nighttime noise exposure. It has been hypothesized that sleep disturbance might mediate the association of aircraft noise exposure and cognitive impairment in children. This study involves secondary analysis of data from the Munich Study and the UK Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) Study sample to test this. In the Munich study, 330 children were assessed on cognitive measures in three measurement waves a year apart, before and after the switchover of airports. Self-reports of sleep quality were analyzed across airports, aircraft noise exposure and measurement wave to test whether changes in nighttime noise exposure had any effect on reported sleep quality, and whether this showed the same pattern as for changes in cognitive performance. For the UK sample of the RANCH study, night noise contour information was linked to the children's home and related to sleep disturbance and cognitive performance. In the Munich study, analysis of sleep quality questions showed no consistent interactions between airport, noise, and measurement wave, suggesting that poor sleep quality does not mediate the association between noise exposure and cognition. Daytime and nighttime aircraft noise exposure was highly correlated in the RANCH study. Although night noise exposure was significantly associated with impaired reading and recognition memory, once home night noise exposure was centered on daytime school noise exposure, night noise had no additional effect to daytime noise exposure. These analyses took advantage of secondary data available from two studies of aircraft noise and cognition. They were not initially designed to examine sleep disturbance and cognition, and thus, there are methodological limitations which make it less than ideal in giving definitive answers to these questions. In conclusion, results from both studies suggest that night aircraft noise exposure does not appear to add any cognitive performance decrement to the cognitive decrement induced by daytime aircraft noise alone. We suggest that the school should be the main focus of attention for protection of children against the effects of aircraft noise on school performance.

Aircraft noise effects on sleep: Mechanisms, mitigation and research needs

Abstract: There is an ample number of laboratory and field studies which provide sufficient evidence that aircraft noise disturbs sleep and, depending on traffic volume and noise levels, may impair behavior and well-being during the day. Although clinical sleep disorders have been shown to be associated with increased risk of cardiovascular diseases, only little is known about the long-term effects of aircraft noise disturbed sleep on health. National and international laws and guidelines try to limit aircraft noise exposure facilitating active and passive noise control to prevent relevant sleep disturbances and its consequences. Adopting the harmonized indicator of the European Union Directive 2002/49/EC, the WHO Night Noise Guideline for Europe (NNG) defines four Lnight , outside ranges associated with different risk levels of sleep disturbance and other health effects ( 55 dBA). Although traffic patterns differing in number and noise levels of events that lead to varying degrees of sleep disturbance may result in the same Lnight , simulations of nights with up to 200 aircraft noise events per night nicely corroborate expert opinion guidelines formulated in WHO's NNG. In the future, large scale field studies on the effects of nocturnal (aircraft) noise on sleep are needed. They should involve representative samples of the population including vulnerable groups like children and chronically ill subjects. Optimally, these studies are prospective in nature and examine the long-term consequences of noise-induced sleep disturbances. Furthermore, epidemiological case-control studies on the association of nocturnal (aircraft) noise exposure and cardiovascular disease are needed. Despite the existing gaps in knowledge on long-term health effects, sufficient data are available for defining limit values, guidelines and protection concepts, which should be updated with the availability of new data.

Characteristics of the Shock Noise Component of Jet Noise

Abstract: The characteristics of the flow and the noise of shock-containing jets have been studied for nearly three decades. It is now established that broadband shock-associated noise is generated by the interaction of the downstream-convecting coherent structures of the jet flow with the shock cells in the jet plume. Past analyses of far-field data have been carried out with the total measured noise, which contains both the turbulent mixing noise and shock noise. In this study, these two components are first separated and extracted from the total spectra. Both convergent and convergent-divergent nozzles are considered. The decomposition is made possible by a recently developed scaling methodology for turbulent mixing noise, which provides excellent collapse of the mixing noise spectra from jets at all velocities but at a fixed temperature ratio. The characteristics of the shock component alone are investigated. A surprising effect of jet temperature on shock noise is established for the first time: the levels increase as the jet is first heated; however, the levels do not increase with further increase in jet temperature. The physical phenomenon responsible for this saturation of levels is not known at this time. The intensity for shock noise in the forward quadrant does not scale as the fourth power (shock exponent) of √|M 2 j -M 2 D | but spans a range from 2.9 to 6.17, depending on the radiation angle and the jet temperature ratio. It is not straightforward to collapse the shock spectra. It is also established for the first time that nonlinear propagation effects are manifested at lower radiation angles, in which the shock component is dominant. The physical phenomenon that triggers the onset of nonlinear propagation for the shock noise could not be identified. The characteristics of the correlation functions at the lower inlet angles for subsonic and supersonic jets are different, attesting to the different noise generation mechanisms.

Trends in aircraft noise annoyance: The role of study and sample characteristics

Abstract: This study assesses the effects of aircraft noise on residential satisfaction, an important indicator of subjective well-being. A structural equation model is specified that estimates the relationships between objective variables, noise annoyance variables and residential satisfaction. Secondary data-analysis is used to estimate the model. The survey was conducted in 1996/1997 among the population living within a 25-km radius of Amsterdam Schiphol, the largest airport in the Netherlands. The effect of aircraft noise annoyance is found to be relatively small. In addition, the objective level of aircraft noise exposure is found to be a better predictor of residential satisfaction than its subjective counterpart. The most important determinants of residential satisfaction are found to be road traffic noise annoyance, age and neighbor noise annoyance. © 2010 Elsevier Ltd. All rights reserved.

Experimental assessment of low noise landing gear component design

Abstract: Landing gear related airframe noise is one of the dominant aircraft noise components at approach, so continued research efforts to reduce landing gear noise are essential. This paper describes further development of an advanced low noise main landing gear that was previously designed and tested in the European SILENCER project. The work was carried out under the current European co-financed TIMPAN project (Technologies to IMProve Airframe Noise) using a 1/4 scaled landing gear model that was tested in the German-Dutch Wind Tunnel. A variety of gear configurations were tested including a new side-stay design and various modifications to the bogie inclination, wheel spacing, bogie fairings with different flow transparency, leg-door configurations and brake fairings. The farfield noise data from the tests are compared with results from a landing gear noise prediction model, transposed to full scale flight conditions and compared with the full scale test data obtained for the original SILENCER advanced A340 s...

Quasi-Experimental Evidence on the Effect of Aircraft Noise on Apartment Rents

Abstract: Inferring the implicit price of an environmental good hinges on ceteris paribus conditions that are often hard to justify. This paper uses an unexpected change in flight regulations as source of exogenous variation and identifies aircraft noise effects from price adjustments in the market for rental apartments. Controlling for spatial and apartment heterogeneity, we find that aircraft noise reduces apartment rents by about 0.5% per decibel. Our results indicate (i) that noise discounts are overestimated in cross-sectional studies because aircraft noise tends to be negatively correlated with omitted neighborhood and housing amenities, and (ii) that noise effects are unlikely to be constant over the entire noise range.

Estimation of the effects of aircraft noise on residential satisfaction

Abstract: This study assesses the effects of aircraft noise on residential satisfaction, an important indicator of subjective well-being. A structural equation model is specified that estimates the relationships between objective variables, noise annoyance variables and residential satisfaction. Secondary data-analysis is used to estimate the model. The survey was conducted in 1996/1997 among the population living within a 25-km radius of Amsterdam Schiphol, the largest airport in the Netherlands. The effect of aircraft noise annoyance is found to be relatively small. In addition, the objective level of aircraft noise exposure is found to be a better predictor of residential satisfaction than its subjective counterpart. The most important determinants of residential satisfaction are found to be road traffic noise annoyance, age and neighbor noise annoyance.

Tool Development for Low-Noise Aircraft Design

Abstract: In order to include aircraft noise as an additional constraint in aircraft design, the German Aerospace Center (DLR) is currently developing a prediction tool named PANAM (Parametric Aircraft Noise Analysis Module) to analyse aircraft noise radiation in the preliminary design stage. This necessitates a detailed noise analysis for each iteration in the design process. As a result, minimal demand in computational time becomes a major requirement and rules out CPU intense Computational Aeroacoustic methods. Instead, aircraft noise is estimated through semi-empirical source models. The implemented noise source models are parametric, meaning that the effects on noise of individual sources can be monitored throughout a simulated flight operation. In addition to common noise evaluation methods, new approaches are implemented in PANAM. The variation of noise levels versus time can be captured and animated. This allows for real-time evaluation of the influence of aircraft operating conditions on noise radiation. Thereby, noise related effects can be identfied and analysed. The level time histories for selected locations as well as animated noise footprints can be generated.

Theoretical Framework for the Simulation of Transport Aircraft Flight

Abstract: This contribution presents a novel simulation theory for a complete fixed-wing aircraft. Novel methods are presented for flight mechanics (fuel planning), turbofan engine simulation (in direct and inverse mode), thermo-physics integration (tire temperature on the ground and fuel temperature in flight) and aircraft noise. At the fundamental level, the framework presented addresses a shortfall in multi-disciplinary integration in aircraft flight, including economic operations, preliminary design and environmental emissions. Validation strategies are introduced for component-level analysis and system integration. Results are presented for geometry models, specific air range and optimal cruise conditions, payload-range performance, fuel temperature of a wing tank, tire heating during normal take-off, aircraft propulsive (jet/nozzle) and non propulsive (landing gear) noise. Selected results are shown for the Boeing B777-300 and the Airbus A380-861.

Plasma actuators for noise control

Abstract: In this article the use of plasma actuation for noise control is reviewed. This research follows the tradition of Geoffrey Lilley who conducted the first experiment relevant to aircraft noise, controlling jet noise by disrupting the helical mode of noise radiation. Advances in electronics, control theory, manufacture process, and diagnostic tools now allow more sophisticated control methods to be developed. In addition to propulsive system noise, airframe noise has now become equally important in defining the overall aircraft noise. Plasma actuation represents a novel method to control aircraft noise, worthy of research and development. Advantages of the approach include simplicity, absence of mechanical moving parts, and fast response. Cases studied in this article demonstrated that the method can be used to attenuate both tonal and more importantly broadband noise radiated by typical aircraft components. The limits and constraints of the methods are also discussed.

Sleep disturbance due to noise: current issues and future research.

Abstract: There is growing interest in carrying out further research to understand and reduce the impact of aircraft noise on airport neighborhood in anticipation of the projected substantial increase in global aviation. Soundscapes provide new analytical methods and a broader, more comprehensive appreciation of the aural environment, which may have a useful role in understanding noise-induced sleep disturbance and annoyance. Current noise metrics like Leq do not provide a common language to report noise environment to residents, which is a key obstacle to effective noise management and acceptance. Non-auditory effects complicate the production of consistent dose-response functions for aircraft noise affecting sleep and annoyance. There are various end-points that can be chosen to assess the degree of sleep disturbance, which has detracted from the clarity of results that has been communicated to wider audiences. The World Health Organization (WHO-Europe) has produced Night Noise Guidelines for Europe, which act as a clear guide for airports and planners to work towards. Methodological inadequacies and the need for simpler techniques to record sleep will be considered with the exciting potential to greatly increase cost-effective field data acquisition, which is needed for large scale epidemiological studies.

Methodological proposals for improved assessments of the impact of traffic noise upon human health

Abstract: Several methodological shortcomings still hinder the inclusion of transport noise as an established impact category within life cycle assessment (LCA). Earlier attempts to quantify the health damages caused by traffic noise yielded valuable results from an academic point of view, but these were of limited use in the context of everyday LCA practice. An enhanced understanding of traffic noise emission models coupled with a straightforward choice of indicators could lead to faster, more accurate assessments of health impairment due to traffic noise whose results would fittingly serve the purposes of policy makers and the information needs of the general public alike. This article aims to propose the guidelines for such assessments. The assessment method presented takes an incremental approach in similar fashion as previous work in the field done by R. Muller-Wenk. An explanation is provided of how the assumption of linearity leads to a substantial overestimation of noise level increments attributable to additional vehicles, and subsequently to a misjudgement of overall health impacts due to traffic noise. Hence, an alternative calculation method allowing for better accuracy in the computation of noise level increments is proposed. This method can be easily applied, needless of a specific traffic noise emission model. A more detailed method, based on the state-of-the-art Improved Methods for the Assessment of the Generic Impact of Noise in the Environment (IMAGINE) traffic noise emission model, is also described. This method is to be applied to large-, medium- and small-scale assessments where variations in traffic flow or composition can be reasonably predicted or measured. In the proposed methodology, health impairment due to traffic noise is not aggregated in DALY (disability-adjusted life years). Rather, the results are given in terms of the ‘number of annoyed persons’, which is derived from the synthesis curves relating noise exposure to annoyance presented by Miedema and Oudshoorn. The calculation procedure and data needs to do this are explained. Moreover, the validity of taking the number of annoyed persons as a proxy for overall health impairment due to traffic noise—and the main benefits of doing so—are discussed. Performing the attribution of impacts on a per vehicle-kilometre basis can lead to impact misrepresentations whenever an incremental approach is taken. A different attribution scheme, which takes background noise into account, is thus proposed. The general framework of a method to assess the impact of traffic noise upon human health within LCA is presented. This method, which finds its basis in the work of Muller-Wenk, can be used to evaluate a large number of variations in traffic other than mere increases in overall traffic flows. An application example evaluating the impact of a generic 1,000-km trip of a heavy-duty vehicle through Spain is provided in Section 2.4. The incremental approach seems most adequate for the assessment of the impact of traffic noise upon human health within LCA, albeit the assumption of linearity can significantly distort its results. Likewise, performing the attribution of impacts through generic characterisations of additional vehicle-kilometres may mask the true responsibility of traffic for increasing noise levels, and is therefore advised against. The special characteristics of noise as a pollutant (relevance of spatial data, human perception issues) appear to justify the adoption of a distinct indicator, namely ‘number of annoyed persons’. Reasonably good estimates of equivalent noise level increases due to proportional increases over pre-existing traffic can be given without using a noise emission model. Yet, the use of state-of-the-art vehicle noise emission models (e.g. IMAGINE) should allow for more accurate assessments, provided sufficient data regarding the spatial distribution of receivers and traffic characteristics (traffic flow, average speed per vehicle type and so forth) are known. Incorporating annoyance as the preferred indicator for the impact of traffic noise upon human health would make assessment results more intelligible and readily applicable to decision making in matters like infrastructure policing and urban planning, whilst placing the focus on damage prevention. In this paper, only road traffic noise is dealt with. However, annoyance curves with a comparably solid scientific background also exist for railway and aircraft noise, which would make comparisons between alternative transportation modes feasible. The use of ‘number of annoyed persons’ instead of DALY units is favoured because it allows for a more straightforward presentation of results, even if it excludes the possibility of aggregation with other health impacts. Nevertheless, the use of DALY is not excluded beforehand, insofar as a scientifically sound relationship between long-term exposure to environmental noise and more severe health conditions is agreed upon by medical experts.

Landing gear noise control using perforated fairings

Abstract: Landing gears of commercial aircraft make an important contribution to total aircraft noise in the approach configuration. Using fairings to shield components from high speed impingement reduces noise. Furthermore, perforating these fairings has been confirmed by flight tests to further enable noise reduction. Following an earlier fundamental study of the application of perforated fairings, a study has been performed to investigate and optimize the benefits of bleeding air through landing gear fairings. By means of wind tunnel tests, an aerodynamic and acoustic survey has been performed on a simplified generic main landing gear to explore the influence of (perforated) fairings on the lower part of the gear. The results show that for this specific case, the application of impermeable fairings reduces noise in the mid- and high frequency range by shielding sharp edged components from high velocity impingement. However, below 1 kHz the noise is shown to increase significantly. Application of the perforations is shown to diminish this low frequency increase whilst maintaining the reduction in the mid- and high frequency range. The aerodynamic and acoustic measurements point in the direction of the separated flow of the fairings interacting with the downstream gear components responsible for the low frequency noise increase. Bleeding of the air through the fairings reduces the large scale turbulence in the proximity of these components and hence diminishes the low frequency noise increase.

Determining the direction of causality between psychological factors and aircraft noise annoyance.

Abstract: In this paper, an attempt is made to establish the direction of causality between a range of psychological factors and aircraft noise annoyance. For this purpose, a panel model was estimated within a structural equation modeling approach. Data were gathered from two surveys conducted in April 2006 and April 2008, respectively, among the same residents living within the 45 Level day-evening-night contour of Amsterdam Airport Schiphol, the largest airport in the Netherlands (n=250). A surprising result is that none of the paths from the psychological factors to aircraft noise annoyance were found to be significant. Yet 2 effects were significant the other way around: (1) from 'aircraft noise annoyance' to 'concern about the negative health effects of noise' and (2) from 'aircraft noise annoyance' to 'belief that noise can be prevented.' Hence aircraft noise annoyance measured at time 1 contained information that can effectively explain changes in these 2 variables at time 2, while controlling for their previous values. Secondary results show that (1) aircraft noise annoyance is very stable through time and (2) that changes in aircraft noise annoyance and the identified psychological factors are correlated.

AzB-2008 and ECAC Doc.29 – two modern European aircraft noise calculation models

Abstract: The European Environmental Noise Directive END requires harmonized prediction methods for the major environmental noise sources Currently two potential candidates are discussed for the modelling of aircraft noise: the 3rd edition of ECAC Doc29 was published in 2005 describing a recommended method for the prediction of aircraft noise around civil airports The German AzB model published in 2008 was developed as a tool for the enforcement of the revised German Act for Protection against Aircraft Noise that came into force in 2007 This paper gives a comparative overview on both methods, the underlying acoustic and aircraft performance models and their usability for different fields of application

Department of Navy Jet Noise Reduction Project Overview

Abstract: : High performance military aircraft represent the single largest noise source for Sailors on board aircraft carriers resulting in health issues, compromised operations and costly litigation. Unfortunately, tactical aircraft have not been able to leverage much of the available significant noise reduction technologies from commercial aircraft due to their low bypass ratio jet engines and resulting high temperature, high velocity exhaust streams. Tactical aircraft noise remains a problem from both community noise and personnel exposure perspectives. In response to the problem and recent Senior Leadership direction, the Office of Naval Research initiated the Jet Noise Reduction (JNR) Project as part of the Noise-Induced Hearing Loss (NIHL) Program. The JNR Project's over-arching objective is to realize and transition significant jet noise reduction technologies through coordinated S&T efforts. This objective will be accomplished through establishing a sustained S&T effort in fundamental jet noise understanding, predictive capability and measurement/validation capability and through developing, demonstrating and transitioning jet noise reduction technologies in support of the Warfighter and the Community. In fiscal year 2010, initial funding was allocated to support the basic program structure and for the two main tasks given high priority- developing a physics-based understanding of jet noise and developing standards to facilitate high quality jet noise measurements. An overview of the JNR Project will be presented as well as some preliminary results and a strategic outlook.

Airframe noise: high lift device noise

Abstract: High lift devices, together with landing gears, are the main sources of airframe noise during the approach-and-landing phase of aircraft flight Typical high lift devices include leading edge slats and trailing edge flaps Other high-lift-related noise-generating devices include spoilers if deployed during a steep approach operation All the above aerodynamic devices are retracted during the cruise phase of aircraft operation A slat, when deployed, forms a cove region between the slat and the central main element of the aircraft wing Flow separation, flow recirculation, an unsteady shear layer, and slat settings together generate noise of mainly broadband content For a flap, the outboard flap side edge and vortex system associated with it are the main sources of noise The intensity of high lift device noise generally follows a power law of flow velocity The main sources of noise are identified and described in this chapter Introduction is provided concerning main semi-empirical and computational fluid dynamics methods Noise attenuation methods are also described Keywords: acoustics; aircraft noise; airframe noise; high lift devices; slat; flap; acoustic control; flow control

Aircraft Noise Regulation, Airline Service Quality, and Social Welfare: the Monopoly Case

Abstract: This paper presents a theoretical approach that attempts to illuminate questions about aircraft noise, models the effect of noise limits on an airline’s scheduling, traffic, and aircraft size, and finally explores the social welfare implications of addressing aircraft noise problem with noise limits. The author notes that aircraft are significantly quieter than they used to be due to improved aircraft technology, yet with ever more air travel forecast and the expected expansion of existing airports and addition or new ones, there is a growing trend for airport noise restrictions. The model also examines the social welfare implications of using noise limits to address aircraft noise problems. In concluding, the author notes that the models presented could be adapted to analyze aircraft exhaust emissions, as the industry attempts to reduce aviation’s contribution to global warming.

Optimal Approach Minimizing Aircraft Noise and Fuel Consumption

Abstract: The objective of this paper is to develop a model to find and evaluate optimal flight paths in order to minimize aircraft noise levels around airports and fuel consumption. Aircraft flight dynamics and trajectories have been considered. A continuous descent approach has been found to be the optimal approach procedure minimizing noise levels and fuel consumption. Performance of optimal approach procedure and its comparison to Integrated Noise Model standard procedures have been presented and discussed.