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ICAO Annex 16 regulations are used to certify the acoustic performance of subsonic transport aircraft. Each aircraft is classified according to the measured EPNL levels at specific certification locations along the approach and departure. By simulating this certification process, it becomes possible to identify all relevant parameters and assess promising measures to reduce the noise certification levels in compliance with the underlying ICAO regulations, i.e., allowable operating conditions of the aircraft. Furthermore, simulation is the only way to enable an assessment of novel technology and non-existing vehicle concepts, which is the main motivation behind the presented research activities. Consequently, the ICAO Annex 16 regulations are integrated into an existing noise simulation framework at DLR, and the virtual noise certification of novel aircraft concepts is realized at the conceptual design phase. The predicted certification levels can be directly selected as design objectives in order to realize an advantageous ICAO noise category for a new aircraft design, i.e., simultaneously accounting for the design and the resulting flight performance. A detailed assessment and identification of operational limits and allowable flight procedures for each conceptual aircraft design under consideration is enabled. Sensitivity studies can be performed for the relevant input parameters that influence the predicted noise certification levels. Specific noise sources with a dominating impact on the certification noise levels can be identified, and promising additional low-noise measures can be applied within the conceptual design phase. The overall simulation process is applied to existing vehicles in order to assess the validity of the simulation resultsfcompared to published data. Thereafter, the process is applied to some DLR low-noise aircraft concepts to evaluate their noise certification levels. These results can then be compared to other standard noise metrics that are typically applied in order to describe aircraft noise, e.g., SEL isocontour areas. It can be demonstrated that certain technologies can significantly reduce the noise impact along most of an approach or departure flight track but have only a limited influence on the noise certification levels and vice versa. Finally, an outlook of the ongoing developments is provided, in order to apply the new simulation process to supersonic aircraft. Newly proposed regulations for such concepts are implemented into the process in order to evaluate these new regulations and enable direct comparison with existing regulations.
Michel Nöding; Lothar Bertsch. Application of Noise Certification Regulations within Conceptual Aircraft Design. Aerospace 2021, 8, 210 .
AMA StyleMichel Nöding, Lothar Bertsch. Application of Noise Certification Regulations within Conceptual Aircraft Design. Aerospace. 2021; 8 (8):210.
Chicago/Turabian StyleMichel Nöding; Lothar Bertsch. 2021. "Application of Noise Certification Regulations within Conceptual Aircraft Design." Aerospace 8, no. 8: 210.
The investigation of technologies that can improve the sustainability of the air transport system requires not only the development of alternative fuel concepts and novel vehicle technologies but also the definition of appropriate assessment strategies. Regarding noise, the assessment should reflect the situation of communities living near airports, i.e., not only addressing sound levels but also accounting for the annoyance caused by aircraft noise. For this purpose, conventional A-weighted sound pressure level metrics provide initial but limited information as the level- and frequency-dependency of the human hearing is accounted for in a simplified manner. Ideally, subjective evaluations are required to adequately quantify the perceived short-term annoyance associated with aircraft noise. However, listening tests are time-consuming and not suitable to be applied during the conceptual aircraft design stage, where a large solution space needs to be explored. Aiming at bridging this gap, this work presents a methodology for the sound quality assessment of computational aircraft noise predictions, which is hereby conducted in terms of objective psychoacoustic metrics. The proposed methodology is applied to a novel medium-range vehicle with fan noise shielding architecture during take-off and landing procedures. The relevance of individual sound sources, i.e., airframe and engine noise contributions, and their dependencies on the aircraft architecture and flight procedures are assessed in terms of loudness, sharpness, and tonality. Moreover, the methodology is steered towards community noise assessment, where the impacts on short-term annoyance brought by the novel aircraft design are analysed. The assessment is based on the modified psychoacoustic annoyance, a metric that provides a quantitative description of human annoyance as a combination of different hearing sensations. The present work is understood as an essential step towards low-annoyance aircraft design.
Gil Felix Greco; Lothar Bertsch; Tobias P. Ring; Sabine C. Langer. Sound quality assessment of a medium-range aircraft with enhanced fan-noise shielding design. CEAS Aeronautical Journal 2021, 1 -13.
AMA StyleGil Felix Greco, Lothar Bertsch, Tobias P. Ring, Sabine C. Langer. Sound quality assessment of a medium-range aircraft with enhanced fan-noise shielding design. CEAS Aeronautical Journal. 2021; ():1-13.
Chicago/Turabian StyleGil Felix Greco; Lothar Bertsch; Tobias P. Ring; Sabine C. Langer. 2021. "Sound quality assessment of a medium-range aircraft with enhanced fan-noise shielding design." CEAS Aeronautical Journal , no. : 1-13.
Residents living in the vicinity of airports are exposed to noise from departing and approaching aircraft. Noise may be reduced by introducing novel aircraft technologies into vehicle retrofit, aircraft design and flight procedures. Nowadays, noise assessment and communication of noise are accomplished using conventional noise indicators that consider neither the perception of sound, nor its health effects. To overcome these limitations, this article presents a more comprehensive approach that supports the movement for perception-influenced design in order to reduce the negative environmental impacts and adverse health effects caused by increased air traffic noise. By means of auralization (the acoustical counterpart of visualization), possible future changes can be evaluated by considering the human perception of sound. In this study, in a virtual acoustic environment flyovers of different aircraft types and flight procedures are auralized for ground-based receiver locations, and subsequently evaluated in a psychoacoustic laboratory experiment with respect to short-term noise annoyance. Flight approaches of an existing reference aircraft, a possible low-noise retrofitted vehicle and a future low-noise vehicle design were simulated along standard and tailored flight procedures. To create realistic listening experiences of synthetic flyovers, auralization technologies were further developed regarding source synthesis, transitions between aircraft conditions, sound propagation effects and immersive sound reproduction. Listening experiments revealed significant annoyance reductions for low-noise aircraft types and tailored flight procedures, and that maximum benefit is achieved by the combined optimization of aircraft design and flight procedure. Further, it is shown that spatially distributed receivers need to be considered for a reliable low-noise aircraft technology evaluation. The reduction potential in terms of perceived noise by retrofitting current vehicles and designing new vehicle architectures is thus demonstrated. These findings suggest applying the proposed comprehensive approach to effectively reduce the impact of perceived air traffic noise in the future.
Reto Pieren; Lothar Bertsch; Demian Lauper; Beat Schäffer. Improving future low-noise aircraft technologies using experimental perception-based evaluation of synthetic flyovers. Science of The Total Environment 2019, 692, 68 -81.
AMA StyleReto Pieren, Lothar Bertsch, Demian Lauper, Beat Schäffer. Improving future low-noise aircraft technologies using experimental perception-based evaluation of synthetic flyovers. Science of The Total Environment. 2019; 692 ():68-81.
Chicago/Turabian StyleReto Pieren; Lothar Bertsch; Demian Lauper; Beat Schäffer. 2019. "Improving future low-noise aircraft technologies using experimental perception-based evaluation of synthetic flyovers." Science of The Total Environment 692, no. : 68-81.
A geared turbofan with an increased bypass ratio promises reduced engine noise generation if compared to conventional turbofan engines with lower bypass ratios. As a result, the dominance of other noise sources on an aircraft with geared turbofan engines is emphasized and will become more relevant. Consequently, to get an understanding of the modified noise source ranking due to the new engine concept, a noise assessment of the overall aircraft noise as received on the ground is essential: that is, a so-called system noise assessment. For this study a German Aerospace Center (DLR) and Technical University of Brunswick aircraft design synthesis process with integrated noise prediction capabilities is applied. The noise assessment is not limited to the overall vehicle noise as received on the ground but, moreover, the dominance and ranking of all individual noise sources are discussed. A direct comparison and evaluation of the flight performance and the system noise of the different vehicle variants under consideration are presented. Finally, the geared turbofan engine is also installed on an earlier low-noise aircraft concept featuring engine noise shielding. The influence of low-noise airframe measures in combination with a geared turbofan concept are promising, especially on an airframe architecture dedicated to engine noise shielding.
Lothar Bertsch; Florian Wolters; Wolfgang Heinze; Michael Pott-Pollenske; Jason Blinstrub. System Noise Assessment of a Tube-and-Wing Aircraft with Geared Turbofan Engines. Journal of Aircraft 2019, 56, 1577 -1596.
AMA StyleLothar Bertsch, Florian Wolters, Wolfgang Heinze, Michael Pott-Pollenske, Jason Blinstrub. System Noise Assessment of a Tube-and-Wing Aircraft with Geared Turbofan Engines. Journal of Aircraft. 2019; 56 (4):1577-1596.
Chicago/Turabian StyleLothar Bertsch; Florian Wolters; Wolfgang Heinze; Michael Pott-Pollenske; Jason Blinstrub. 2019. "System Noise Assessment of a Tube-and-Wing Aircraft with Geared Turbofan Engines." Journal of Aircraft 56, no. 4: 1577-1596.
Lothar Bertsch; Wolfgang Heinze; Sebastien Guerin; Markus Lummer; Jan Delfs. 10 years of joint research at DLR and TU Braunschweig toward low-noise aircraft design-what did we achieve? Aeronautics and Aerospace Open Access Journal 2019, 3, 89 -105.
AMA StyleLothar Bertsch, Wolfgang Heinze, Sebastien Guerin, Markus Lummer, Jan Delfs. 10 years of joint research at DLR and TU Braunschweig toward low-noise aircraft design-what did we achieve? Aeronautics and Aerospace Open Access Journal. 2019; 3 (2):89-105.
Chicago/Turabian StyleLothar Bertsch; Wolfgang Heinze; Sebastien Guerin; Markus Lummer; Jan Delfs. 2019. "10 years of joint research at DLR and TU Braunschweig toward low-noise aircraft design-what did we achieve?" Aeronautics and Aerospace Open Access Journal 3, no. 2: 89-105.
Lothar Bertsch; Russell H. Thomas; Laurent Sanders; Ingrid Legriffon. The Aircraft Noise Simulation Working Group (ANSWr) - Tool Benchmark and Reference Aircraft Results. 25th AIAA/CEAS Aeroacoustics Conference 2019, 1 .
AMA StyleLothar Bertsch, Russell H. Thomas, Laurent Sanders, Ingrid Legriffon. The Aircraft Noise Simulation Working Group (ANSWr) - Tool Benchmark and Reference Aircraft Results. 25th AIAA/CEAS Aeroacoustics Conference. 2019; ():1.
Chicago/Turabian StyleLothar Bertsch; Russell H. Thomas; Laurent Sanders; Ingrid Legriffon. 2019. "The Aircraft Noise Simulation Working Group (ANSWr) - Tool Benchmark and Reference Aircraft Results." 25th AIAA/CEAS Aeroacoustics Conference , no. : 1.
Laurent Sanders; Russell H. Thomas; Lothar Bertsch; Ingrid Legriffon; Ian Clark; Jason June; Mathieu Lorteau. The Aircraft Noise Simulation Working Group (ANSWr) – V2 Aircraft Results. 25th AIAA/CEAS Aeroacoustics Conference 2019, 1 .
AMA StyleLaurent Sanders, Russell H. Thomas, Lothar Bertsch, Ingrid Legriffon, Ian Clark, Jason June, Mathieu Lorteau. The Aircraft Noise Simulation Working Group (ANSWr) – V2 Aircraft Results. 25th AIAA/CEAS Aeroacoustics Conference. 2019; ():1.
Chicago/Turabian StyleLaurent Sanders; Russell H. Thomas; Lothar Bertsch; Ingrid Legriffon; Ian Clark; Jason June; Mathieu Lorteau. 2019. "The Aircraft Noise Simulation Working Group (ANSWr) – V2 Aircraft Results." 25th AIAA/CEAS Aeroacoustics Conference , no. : 1.
This contribution to the CEAS special edition Aircraft Noise Generation and Assessment focuses on the simulation of the aircraft noise immission, i.e., the aircraft noise received on the ground. This process includes two steps, the description of the sound emission by the aircraft and the modeling of the sound propagation through the atmosphere. An overview is provided on how aircraft noise immission can be described and assessed by noise descriptors. These quantities can be derived from measurable and computable quantities like maximum sound levels, time-integrated sound levels and the number of aircraft movements. Moreover, a generation of novel noise indices which relate human reactions to noise is presented. Fundamentals of aircraft noise modeling are explained. First, this includes a classification of aircraft noise models into best practice and scientific models and their applicability to the noise mitigation measures described by ICAO’s Balanced Approach to Aircraft Noise Management. Furthermore, the overall workflow of a noise modeling task is explained as well the special role of noise model databases and the simulation of aircraft flight paths. The most common methods used to describe the sound propagation process through the atmosphere are introduced. This covers the modeling of the fundamental propagation effects which are used by all noise model types as well as a description of propagation effects which are of importance only for special modeling tasks and which normally require sophisticated physical approaches. The fundamental difference between best practice and scientific aircraft noise models—i.e., the source modeling—is described in detail thereafter. Best practice models are based on a simple source description. Moreover, a common approach is to combine emission and propagation using pre-calculated noise–power–distance tables. In contrast, scientific models are of multi-source type, i.e., they differentiate between particular noise-generating mechanisms—at least between engine noise and aerodynamic noise. This model type always requires a time step-based flightpath description, whereas the best practice models usually are based on a flightpath description by longer segments. Finally, the selected application examples are presented for both model categories. This covers the range from noise zoning over what-if studies for noise mitigation measures or definition of noise abatement flight procedures up to the modeling of noise reduction measures at the source. Finally, the application of scientific models in the aircraft design phase is explained.
Ullrich Isermann; Lothar Bertsch. Aircraft noise immission modeling. CEAS Aeronautical Journal 2019, 10, 287 -311.
AMA StyleUllrich Isermann, Lothar Bertsch. Aircraft noise immission modeling. CEAS Aeronautical Journal. 2019; 10 (1):287-311.
Chicago/Turabian StyleUllrich Isermann; Lothar Bertsch. 2019. "Aircraft noise immission modeling." CEAS Aeronautical Journal 10, no. 1: 287-311.
Based on the outcome of a workshop on aviation noise, this special issue on aircraft noise generation and assessment has been assembled. Invited contributions on preselected topics have been combined into one overall story line about both the aircraft noise generation and its assessment to provide an overview on the state-of-the-art capabilities in this research field (accounting both for modelling and measuring efforts). Although most relevant topics are covered, the editors do not claim that the collection of contributions is exhaustive for the multidisciplinary and vast research area dealing with aircraft noise. This issue is not restricted to current aircraft technology only, but includes low-noise technologies and novel aircraft design for subsonic and supersonic vehicles. Furthermore, an overview on measurement techniques, aeroacoustic windtunnel design, and low-noise modifications to existing windtunnels is provided. The selected paper contributions are all peer reviewed and display the status quo of experimental and numerical research activities in academia, at research institutes, and in industry.
L. Bertsch; M. Snellen; L. Enghardt; C. Hillenherms. Aircraft noise generation and assessment: executive summary. CEAS Aeronautical Journal 2019, 10, 3 -9.
AMA StyleL. Bertsch, M. Snellen, L. Enghardt, C. Hillenherms. Aircraft noise generation and assessment: executive summary. CEAS Aeronautical Journal. 2019; 10 (1):3-9.
Chicago/Turabian StyleL. Bertsch; M. Snellen; L. Enghardt; C. Hillenherms. 2019. "Aircraft noise generation and assessment: executive summary." CEAS Aeronautical Journal 10, no. 1: 3-9.
Parametric noise assessment in the context of low-noise aircraft design and flight procedure optimization has been around for more than 15 years. Yet reliable and comprehensive uncertainty analysis of the overall aircraft noise-prediction process was not available for parametric tools in the past. This paper presents a methodology to assess the overall uncertainty of DLR, German Aerospace Center’s aircraft system noise simulation with the software Parametric Aircraft Noise Analysis Module (i.e., definition of a general approach to specify uncertainties of the predicted ground noise immission). This allows discussion of the temporal and spatial distribution of the uncertainties. The noise-prediction uncertainties vary between locations along the flight path. The impact on exposure–response relationships due to the variation in uncertainty is discussed (i.e., the influence of varying noise source dominance along simulated flights). Results of this uncertainty assessment along typical flight procedures and their impact on the A-weighted maximum sound pressure level LA,max are presented.
Lothar Bertsch; Beat Schäffer; Sébastien Guérin. Uncertainty Analysis for Parametric Aircraft System Noise Prediction. Journal of Aircraft 2019, 56, 529 -544.
AMA StyleLothar Bertsch, Beat Schäffer, Sébastien Guérin. Uncertainty Analysis for Parametric Aircraft System Noise Prediction. Journal of Aircraft. 2019; 56 (2):529-544.
Chicago/Turabian StyleLothar Bertsch; Beat Schäffer; Sébastien Guérin. 2019. "Uncertainty Analysis for Parametric Aircraft System Noise Prediction." Journal of Aircraft 56, no. 2: 529-544.
L. Bertsch; M. Snellen; L. Enghardt; C. Hillenherms. Correction to: Aircraft noise generation and assessment. CEAS Aeronautical Journal 2019, 10, 355 -355.
AMA StyleL. Bertsch, M. Snellen, L. Enghardt, C. Hillenherms. Correction to: Aircraft noise generation and assessment. CEAS Aeronautical Journal. 2019; 10 (1):355-355.
Chicago/Turabian StyleL. Bertsch; M. Snellen; L. Enghardt; C. Hillenherms. 2019. "Correction to: Aircraft noise generation and assessment." CEAS Aeronautical Journal 10, no. 1: 355-355.
Today, main hub airports are already at their capacity limit and hence, smaller airports have become more interesting for providing point-to-point connections. Unfortunately, the use of regional airports induces an increased environmental footprint for the population living around it. In an attempt to solve the related problems, the research project Coordinated Research Centre 880 aims to examine the fundamentals of a single-aisle aircraft with active high-lift configuration powered by two geared ultra-high bypass turbofan engines mounted over the wing. Low direct operating costs, noise shielding due to the over-wing configuration, and short runway lengths are the main advantages. Highlighting the performance, economical and noise benefits of a geared ultra-high bypass engine is the key aim of this paper. This assessment includes a correspondingly adjusted aircraft. Open literature values are applied to design the two investigated bypass ratios; a reference engine with a bypass ratio of 5 and 17 respectively. This study shows that a careful selection of engine mass flow, turbine entry temperature and overall pressure ratio determines the desirable bypass ratio. The aircraft direct operating costs drop by 5.7% when comparing the designed conventional with a future ultra-high bypass ratio engine. Furthermore, the sound at source for a selected mission and operating condition can be reduced by 7 dB. A variable bypass nozzle area for the ultra-high bypass ratio engine is analysed in terms of performance and operability. An increase of safety margin is shown for the turbofan engine with a variable bypass nozzle. It is concluded that this unconventional aircraft configuration with ultra-high bypass ratio engines mounted over the wing has the potential to relieve main hub airports and reduce the environmental impact.
Daniel Giesecke; Marcel Lehmler; Jens Friedrichs; Jason Blinstrub; Lothar Bertsch; Wolfgang Heinze. Evaluation of ultra-high bypass ratio engines for an over-wing aircraft configuration. Journal of the Global Power and Propulsion Society 2018, 2, 8SHP7K .
AMA StyleDaniel Giesecke, Marcel Lehmler, Jens Friedrichs, Jason Blinstrub, Lothar Bertsch, Wolfgang Heinze. Evaluation of ultra-high bypass ratio engines for an over-wing aircraft configuration. Journal of the Global Power and Propulsion Society. 2018; 2 ():8SHP7K.
Chicago/Turabian StyleDaniel Giesecke; Marcel Lehmler; Jens Friedrichs; Jason Blinstrub; Lothar Bertsch; Wolfgang Heinze. 2018. "Evaluation of ultra-high bypass ratio engines for an over-wing aircraft configuration." Journal of the Global Power and Propulsion Society 2, no. : 8SHP7K.
Jason Blinstrub; Lothar Bertsch; Wolfgang Heinze. Assessment of the Noise Immission along Approach and Departure Flightpaths for Different SFB 880 Vehicle Concepts. 2018 AIAA/CEAS Aeroacoustics Conference 2018, 1 .
AMA StyleJason Blinstrub, Lothar Bertsch, Wolfgang Heinze. Assessment of the Noise Immission along Approach and Departure Flightpaths for Different SFB 880 Vehicle Concepts. 2018 AIAA/CEAS Aeroacoustics Conference. 2018; ():1.
Chicago/Turabian StyleJason Blinstrub; Lothar Bertsch; Wolfgang Heinze. 2018. "Assessment of the Noise Immission along Approach and Departure Flightpaths for Different SFB 880 Vehicle Concepts." 2018 AIAA/CEAS Aeroacoustics Conference , no. : 1.
The strategic European paper “Flightpath 2050” claims dramatic reductions of noise for aviation transport scenarios in 2050: “...The perceived noise emission of flying aircraft is reduced by 65%. These are relative to the capabilities of typical new aircraft in 2000...”. There is a consensus among experts that these far reaching objectives cannot be accomplished by application of noise reduction technologies at the level of aircraft components only. Comparably drastic claims simultaneously expressed in Flightpath 2050 for carbon dioxide and NOX reduction underline the need for step changes in aircraft technologies and aircraft configurations. New aircraft concepts with entirely different propulsion concepts will emerge, including unconventional power supplies from renewable energy sources, ranging from electric over hybrid to synthetic fuels. Given this foreseen revolution in aircraft technology the question arises, how the noise impact of these new aircraft may be assessed. Within the present contribution, a multi-level, multi-fidelity approach is proposed which enables aircraft noise assessment. It is composed by coupling noise prediction methods at three different levels of detail. On the first level, high fidelity methods for predicting the aeroacoustic behavior of aircraft components (and installations) are required since in the early stages of the development of innovative noise reduction technology test data is not available. The results are transferred to the second level, where radiation patterns of entire conventional and future aircraft concepts are assembled and noise emissions for single aircraft are computed. In the third level, large scale scenarios with many aircraft are considered to accurately predict the noise exposure for receivers on the ground. It is shown that reasonable predictions of the ground noise exposure level may be obtained. Furthermore, even though simplifications and omissions are introduced, it is shown that the method is capable of transferring all relevant physical aspects through the levels.
Jan Delfs; Lothar Bertsch; Christoph Zellmann; Lennart Rossian; Ehsan Kian Far; Tobias Ring; Sabine C. Langer. Aircraft Noise Assessment—From Single Components to Large Scenarios. Energies 2018, 11, 429 .
AMA StyleJan Delfs, Lothar Bertsch, Christoph Zellmann, Lennart Rossian, Ehsan Kian Far, Tobias Ring, Sabine C. Langer. Aircraft Noise Assessment—From Single Components to Large Scenarios. Energies. 2018; 11 (2):429.
Chicago/Turabian StyleJan Delfs; Lothar Bertsch; Christoph Zellmann; Lennart Rossian; Ehsan Kian Far; Tobias Ring; Sabine C. Langer. 2018. "Aircraft Noise Assessment—From Single Components to Large Scenarios." Energies 11, no. 2: 429.
The Airbus A320neo family and the Bombardier CSeries can come equipped with a geared turbofan of increased bypass ratio. Such an engine concept promises reduced engine noise generation if compared to conventional\ud turbofan engines with lower bypass ratios. As a result, the dominance of other noise sources on-board of an aircraft with geared turbofan engines are emphasized and will become more relevant. Consequently, to get an understanding of the modified noise source ranking due to the new engine concept, a noise assessment of the overall aircraft noise as received on the ground is essential, i.e., a so called system noise assessment. \ud For this study a DLR & TU Braunschweig aircraft design synthesis process with integrated noise prediction capabilities is applied. An interface to process external input data allows the implementation of high-fidelity\ud simulation results for the geared engine concept into the overall simulation process, i.e. including all required\ud engine parameters for the noise prediction. The focus lies on the comparison of existing engine concepts and\ud their impact on the overall vehicle design, flight performance, and ultimately the system noise. The noise assessment is not limited to the overall vehicle noise as received on the ground but moreover the dominance and\ud ranking of all individual noise sources is discussed. A direct comparison and evaluation of the flight performance\ud and the system noise of the different vehicle variants under consideration is presented.\ud Among the vehicle variants, one aircraft is adapted to better match the engine concept. A geared turbofan\ud engine concept will come with an inherent and advantageous implication on the overall aircraft performance, i.e., reduced specific fuel consumption. Since such beneficial characteristics are identified in the simulation results, the overall vehicle design is consequently adapted to fully exploit these characteristics. Furthermore, several known measures to reduce the airframe noise contribution are simulated on board of the vehicles under consideration. The system noise assessment will identify the impact of these technologies on the overall aircraft noise for each variant.\ud Finally, the geared turbofan engine is also installed on board of an earlier low-noise aircraft concept featuring\ud engine noise shielding. The impact of the new engine in combination with shielding effects is assessed. It is\ud demonstrated that the influence of low-noise airframe measures in combination with geared turbofan aircraft\ud concept are promising, especially on an airframe architecture dedicated to engine noise shielding
Lothar Bertsch; Florian Wolters; Wolfgang Heinze; Michael Pott-Pollenske; Jason Blinstrub. System noise assessment of a tube-and-wing aircraft with geared turbofan engines. 2018 AIAA Aerospace Sciences Meeting 2018, 1 .
AMA StyleLothar Bertsch, Florian Wolters, Wolfgang Heinze, Michael Pott-Pollenske, Jason Blinstrub. System noise assessment of a tube-and-wing aircraft with geared turbofan engines. 2018 AIAA Aerospace Sciences Meeting. 2018; ():1.
Chicago/Turabian StyleLothar Bertsch; Florian Wolters; Wolfgang Heinze; Michael Pott-Pollenske; Jason Blinstrub. 2018. "System noise assessment of a tube-and-wing aircraft with geared turbofan engines." 2018 AIAA Aerospace Sciences Meeting , no. : 1.
Reto Pieren; Lothar Bertsch; Jason Blinstrub; Schäffer Beat; Wunderli Jean Marc. Simulation process for perception-based noise optimization of conventional and novel aircraft concepts. 2018 AIAA Aerospace Sciences Meeting 2018, 1 .
AMA StyleReto Pieren, Lothar Bertsch, Jason Blinstrub, Schäffer Beat, Wunderli Jean Marc. Simulation process for perception-based noise optimization of conventional and novel aircraft concepts. 2018 AIAA Aerospace Sciences Meeting. 2018; ():1.
Chicago/Turabian StyleReto Pieren; Lothar Bertsch; Jason Blinstrub; Schäffer Beat; Wunderli Jean Marc. 2018. "Simulation process for perception-based noise optimization of conventional and novel aircraft concepts." 2018 AIAA Aerospace Sciences Meeting , no. : 1.
Airframe noise is becoming increasingly important during approach, even reaching higher noise levels than the engines in some cases. More people are a_ected due to low ight altitudes and _xed tra_c routing associated with typical approaches. For most air- craft types, the landing gear system is a dominant airframe noise source. However, this element can only be modeled in an approximate manner in wind tunnel experiments. In this research, yovers of landing aircraft were recorded using a 32 microphone array. Functional beamforming was applied to analyze the noise emissions from the landing gear system. It was con_rmed that for some aircraft types, such as the Airbus A320 and the Fokker 70, the nose landing gear is a dominant noise source during approach. The correlation between the noise levels generated by the landing gear and the aircraft velocity was found to be signi_cant, explaining about 70% of the variability found in the noise levels, which is in good agreement with all known theory. Moreover, the experimental results for the Airbus A320 measurements were compared with those obtained using the DLR system noise pre- diction tool PANAM. Whereas the total aircraft noise levels were in good agreement, the measurements indicate a higher contribution from the nose landing gear noise compared to the predictions
Roberto Merino-Martinez; Lothar Bertsch; Dick G. Simons; Mirjam Snellen. Analysis of landing gear noise during approach. 22nd AIAA/CEAS Aeroacoustics Conference 2016, 1 .
AMA StyleRoberto Merino-Martinez, Lothar Bertsch, Dick G. Simons, Mirjam Snellen. Analysis of landing gear noise during approach. 22nd AIAA/CEAS Aeroacoustics Conference. 2016; ():1.
Chicago/Turabian StyleRoberto Merino-Martinez; Lothar Bertsch; Dick G. Simons; Mirjam Snellen. 2016. "Analysis of landing gear noise during approach." 22nd AIAA/CEAS Aeroacoustics Conference , no. : 1.
Aircraft noise analysis has been a principal topic regarding environmental issues for aviation industry and research community. Besides noise abatement procedures the focus is leaning more towards reduction at the source itself. Noise prediction for optimization purposes of existing technologies as well as integration within design processes of aircraft is required more than ever. Relatively new and still under development, yet already proven to be beneficial is the approach of noise prediction within conceptual aircraft design. To succeed it requires a componential and parametric prediction approach with dominating noise sources adequately represented and modeled. One missing source in such a prediction scheme is the flap side edge. Recent research efforts have again indicated potential dominance of this noise source. Due to complexity of the source mechanisms and practicability limitations it is difficult to investigate the contribution of the flap side edge on the overall aircraft noise. Therefore, a parametric and componential simulation approach is applied to perform a flap side edge noise analysis. For this purpose a semi-empirical prediction model is implemented within an existing parametric aircraft noise analysis module. The aim of the current research study is to analyze the flap side edge noise and provide more insight and knowledge of its potential dominance.
M. R. Ramdjanbeg; L. Bertsch; K.-S. Rossignol; D. G. Simons. Flap Side-Edge Noise Prediction Within Conceptual Aircraft Design. Notes on Numerical Fluid Mechanics and Multidisciplinary Design 2016, 731 -742.
AMA StyleM. R. Ramdjanbeg, L. Bertsch, K.-S. Rossignol, D. G. Simons. Flap Side-Edge Noise Prediction Within Conceptual Aircraft Design. Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 2016; ():731-742.
Chicago/Turabian StyleM. R. Ramdjanbeg; L. Bertsch; K.-S. Rossignol; D. G. Simons. 2016. "Flap Side-Edge Noise Prediction Within Conceptual Aircraft Design." Notes on Numerical Fluid Mechanics and Multidisciplinary Design , no. : 731-742.
Aircraft exterior noise is typically reduced by optimizing an isolated aircraft component. The noise emission of this component is optimized with high-fidelity tools or wind tunnel measurements. However, if installed on-board of the aircraft the optimization may not have the desired effect on the total noise impact due to propagation effects or the interaction with other components. Hence, a method is presented, that derives noise reduction requirements for aircraft components based on the total aircraft noise impact. The method is implemented in a parametric aircraft noise prediction tool and applied to a reference aircraft. The aim is to use the noise requirements within conceptual aircraft design to obtain low-noise aircraft in a target-oriented way. Ultimately, this may be a first step towards a noise-to-design process.
Jason Blinstrub; Lothar Bertsch. Towards an Impact-Based Noise Reduction Method for Conceptual Aircraft Design. Notes on Numerical Fluid Mechanics and Multidisciplinary Design 2016, 687 -697.
AMA StyleJason Blinstrub, Lothar Bertsch. Towards an Impact-Based Noise Reduction Method for Conceptual Aircraft Design. Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 2016; ():687-697.
Chicago/Turabian StyleJason Blinstrub; Lothar Bertsch. 2016. "Towards an Impact-Based Noise Reduction Method for Conceptual Aircraft Design." Notes on Numerical Fluid Mechanics and Multidisciplinary Design , no. : 687-697.
System noise has been integrated as an additional design objective within conceptual aircraft design. The DLR system noise prediction tool PANAM accounts for individual\ud noise sources depending on their geometry and operating conditions. PANAM is integrated into the existing aircraft design framework PrADO from the Technical University\ud of Braunschweig in order to realize a design-to-noise simulation process. In addition, a ray-tracing tool from DLR, SHADOW, is incorporated into the simulation framework in order to account for structural engine noise shielding. The overall simulation process is then applied to identify promising low-noise aircraft concepts.\ud The presented application aims at fan noise reduction through shielding. For the selected reference aircraft, the fan is a major noise source during both landing and takeoff.\ud It is demonstrated, that the aircraft designers influence on the environmental vehicle characteristics is significant at the conceptual design phase. Usually, a trade-off between\ud extensive engine noise shielding and economical flight performance is inevitable. The new design-to-noise process is well suitable to assess all four measures of ICAOs balanced approach
Lothar Bertsch; Wolfgang Heinze; Markus Lummer. Application of an Aircraft Design-To-Noise Simulation Process. 14th AIAA Aviation Technology, Integration, and Operations Conference 2014, 1 .
AMA StyleLothar Bertsch, Wolfgang Heinze, Markus Lummer. Application of an Aircraft Design-To-Noise Simulation Process. 14th AIAA Aviation Technology, Integration, and Operations Conference. 2014; ():1.
Chicago/Turabian StyleLothar Bertsch; Wolfgang Heinze; Markus Lummer. 2014. "Application of an Aircraft Design-To-Noise Simulation Process." 14th AIAA Aviation Technology, Integration, and Operations Conference , no. : 1.