Добірка наукової літератури з теми "Numerical optimization and civil aircraft engine noise"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Numerical optimization and civil aircraft engine noise".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Numerical optimization and civil aircraft engine noise"

1

Chen, Min, Zihao Jia, Hailong Tang, Yi Xiao, Yonghang Yang, and Feijia Yin. "Research on Simulation and Performance Optimization of Mach 4 Civil Aircraft Propulsion Concept." International Journal of Aerospace Engineering 2019 (January 14, 2019): 1–19. http://dx.doi.org/10.1155/2019/2918646.

Повний текст джерела
Анотація:
Supersonic civil aircraft is of a promising area in the development of future civil transport, and aircraft propulsion system is one of the key issues which determine the success of the aircraft. To get a good conceptual design and performance investigation of the supersonic civil aircraft engine, in this article, a fast, versatile as well as trust-worthy numerical simulation platform was established to analyze the Mach 4 turbine-based combined cycle (TBCC) engine concept so as to be applied to the supersonic civil aircraft. First, a quick and accurate task requirement analysis module was newly established to analyze the mission requirement of the Mach 4 supersonic civil aircraft. Second, the TBCC engine performance simulation model was briefly presented and the number of engines on the supersonic civil aircraft was analyzed, considering single engine inoperative. Third, the Stone model and the DLR method were investigated to estimate the engine jet noise and the NOx emission of the Mach 4 supersonic civil aircraft. Finally, a multiobjective optimization tool made up of a response surface method and a genetic algorithm was developed to optimize the design parameters and the control law of the TBCC engine, in order to make the Mach 4 supersonic civil aircraft engine with better performance, lower noise, and lower emissions. The uniqueness of the developed analysis tool lies in that it affords a numerical simulation platform capable of investigating the task requirement analysis module of the supersonic civil aircraft, engine jet noise prediction model, and the NOx emission prediction model, as well as a multiobjective performance optimization tool, which is beneficial for the conceptual design and performance research of Mach 4 supersonic civil aircraft’s propulsion system.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Moreau, Antoine, Andrej Prescher, Stephen Schade, Maikhanh Dang, Robert Jaron, and Sébastien Guérin. "A framework to simulate and to auralize the sound emitted by aircraft engines." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 1 (November 30, 2023): 7160–71. http://dx.doi.org/10.3397/in_2023_1073.

Повний текст джерела
Анотація:
In civil aviation, the well-established Effective Perceived Noise Level (EPNL) has remained, so far, a simple but reliable psycho-acoustic metric, representing the backbone of noise regulation politics and leading to quieter aircraft turbofan engines. However, the recent changes induced by further acoustic optimization of engines, or the introduction of innovative designs, suggest that a more refined assessment than the sole EPNL metric is needed, which is based on sound auralization. The paper presents a framework of simulation tools that are currently being developed at the DLR Engine Acoustics Department with the goal of assessing novel designs at a very early development stage. This framework allows to simulate acoustically an engine flyover and to produce audible signals as perceived by a virtual observer standing on the ground. The source calculation is performed by the tool PropNoise and relies on analytical physics-based models for the fan noise sources, and Stone's semi-empirical jet noise model. The subsequent tool VIOLIN simulates the propagation of sound through the atmosphere and the ground reflection effects. Finally, the spectrograms of the broadband and tonal noise components are converted to audible sound by the auralization tool CORAL. The procedure is applied to a realistic engine test case and compared with experimentally recorded sound.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

He, Sibo, Yimeng Li, Zidong Pu, and Wenbo Rao. "Aerodynamic Calculation and Computer Numerical Simulation Methods Applied in Jet Engine Research." Highlights in Science, Engineering and Technology 62 (July 27, 2023): 217–27. http://dx.doi.org/10.54097/hset.v62i.10446.

Повний текст джерела
Анотація:
The development status of aero-engines is a sign of a country's technological development level and comprehensive national strength. Jet engines undergone a rapid development since being invented and are widely applied in both commercial and military aircraft nowadays. The objective of jet engines is to provide thrust for aircraft and maintain high performance in different flight segments. Engine design choice must be compromised to balance different selection criteria. This article reviews the development history of jet engines and reviews the development paths of jet engines in various technical fields in detail. It also summarizes the current state and development of jet engines from the civil and military fields and finally looks forward to the future development of jet engines. The discussion of several publications shows that considerable attention has been paid in reducing emissions, increasing fuel efficiency and reducing noise. Advanced manufacturing technologies and materials could improve engine performance. Establish new operations could be another future direction while it has limitations. Bio-fuel could be a promising solution in reducing emissions while its feasibility in meeting real operating conditions still need to be investigated.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ispir, Ali Can, Pedro Miguel Gonçalves, and Bayindir H. Saracoglu. "Analysis of a combined cycle propulsion system for STRATOFLY hypersonic vehicle over an extended trajectory." MATEC Web of Conferences 304 (2019): 03001. http://dx.doi.org/10.1051/matecconf/201930403001.

Повний текст джерела
Анотація:
Hypersonic civil aviation is an important enabler for extremely shorter flight durations for long-haul routes and using unexploited flight altitudes. Combined cycle engine concepts providing extended flight capabilities, i.e. propelling the aircraft from take-off to hypersonic speeds, are proposed to achieve high-speed civil air transportation. STRATOFLY project is a continuation of former European efforts in hypersonic research and aims at developing a commercial reusablevehicle for cruise speed of Mach 8 at stratospheric altitudes as high as 35 km above ground level. The propulsion plant of STRATOFLY aircraft consists of combination of two different type of engines: an array of air turbo rockets and a dualmode ramjet/scramjet. In the present study, 1D transient thermodynamic simulations for this combined cycle propulsion plant have been conducted between Mach 0 to 8 by utilizing 1D inviscid flow transport relations, numerical tools availablein EcosimPro software platform and the European Space Propulsion System Simulation libraries. The optimized engine parameters are achieved by coupling EcosimPro software with Computer Aided Design Optimization which is a differential evolution algorithm developed at the von Karman Institute.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Li, Yejin, Peng Rao, Zhengda Li, and Jianliang Ai. "On-Board Parameter Optimization for Space-Based Infrared Air Vehicle Detection Based on ADS-B Data." Applied Sciences 13, no. 12 (June 8, 2023): 6931. http://dx.doi.org/10.3390/app13126931.

Повний текст джерела
Анотація:
Frequent aviation safety accidents of civil aircraft misses and crashes lead to an urgent need for flight safety assurance. Due to long-time flights over different backgrounds, accompanied by the changes in flight altitude and speed, it is difficult for a conventional space-based infrared detection system to use a set of fixed parameters to meet the stable detection requirement. To enhance the awareness of civil aircraft surveillance, a real-time parameter optimization method based on Automatic Dependent Surveillance-Broadcast (ADS-B) data is proposed. According to the background spectral characteristics and the real-time flight data, the most reasonable spectral band is analyzed, using the joint signal-to-noise/clutter ratio (JSNCR) as the evaluation criteria. Then, an automatic parameter adjustment is used to maximize the integration time and switch the integration capacitor gear. Numerical simulation results show that the JSNCR increased by 1.16 to 1.31 times, and the corresponding noise equivalent target radiant intensity (NET) reduced from 2.4 W/Sr to 1.2 W/Sr compared with a conventional fixed-parameter detection system. This study lays a solid theoretical foundation for the spectral band analysis of space-based AVD system design. Meanwhile, the proposed method can be used as a standard procedure to improve on-board performance.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Ghinet, Sebastian, Patrick Bouche, Thomas Padois, Olivier Doutres, Tenon Charly Kone, Raymond Panneton, and Noureddine Atalla. "Overview of concept designs and results of the New Acoustic Insulation Meta-Material for Aerospace (NAIMMTA) project." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 5 (November 30, 2023): 3402–13. http://dx.doi.org/10.3397/in_2023_0489.

Повний текст джерела
Анотація:
Reducing aircraft cabin noise to improve the comfort of passengers is an important and challenging issue in aeronautics. Relatively uncomfortable high noise levels of around 80 to 90 dBA with strong low frequency range components (below 500 Hz) and a tonal character, predominantly related to the engine fan during take-off and approach, are deemed critical. The conventional acoustic materials seem to have reached their physical limits in terms of sound proofing, and therefore non-conventional solutions, such as metamaterials, are sought for their promising performance such as, a significant noise attenuation rate (dB/m), and the capability to be tuned at tonal or narrow band frequencies. An international collaborative project was created to develop novel technologies aiming at improving the existing noise control systems by obtaining an additional 5 dB noise reduction in the low frequency range (100 to 400 Hz) without deteriorating the thermal insulation. Moreover, the proposed solutions were expected to be tunable with respect to tonal noise (bandwidth of 5 Hz) or narrowband noise (bandwidth of 40 Hz). A major design and integration constraint imposed that the metamaterial had to be embedded in the current existing insulation blanket and add a maximum of 20% additional mass in comparison to the conventional insulation. This paper presents an overview of the various solutions developed from numerical simulations and novel manufacturing procedures development and optimization to performance characterization and validations.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

LAFONT, Victor, Delphine SEBBANE, Frank SIMON, Jean-Paul PINACHO, and Julien CAILLET. "Feasibility of an acoustic liner applied to a Fenestron: experimentation." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 270, no. 9 (October 4, 2024): 2265–76. http://dx.doi.org/10.3397/in_2024_3160.

Повний текст джерела
Анотація:
A helicopter's anti-torque system is a significant contributor to radiated noise. The Fenestron, used on Airbus Helicopters, allows to mitigate the anti-torque noise by masking effect and modulation of the blade distribution. However, unlike aircraft engine nacelles, it does not contain acoustic liners inside the duct to absorb the noise radiated by the rotor blades. This paper describes: first, the (aero-)acoustic tests applied to different acoustic liners optimised to be integrated into a 1/3-scale fenestron mock-up, in order to provide a specific impedance (measurement in impedance tube and aeroacoustic bench); second, the configuration of a mock-up installed in an anechoic room, with an acoustic antenna; third, the acoustic pressure mitigation obtained for several diffusers equiped with liners (variation of RPM and pitch for the purpose of the experiment). It appears that the tested liners are likely to provide a high absorption coefficient in a large frequency range and a significant attenuation when installed in the Fenestron mock-up, in accordance with preliminary simulations. Another paper completes the study with a preliminary numerical assessment of the effect of an absorbing treatment introduced inside the collector or the diffuser, and a design optimization applied to different acoustic liner types, adapted to the mock-up.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Schloesser, Philipp, Michael Meyer, Martin Schueller, Perez Weigel, and Matthias Bauer. "Fluidic actuators for separation control at the engine/wing junction." Aircraft Engineering and Aerospace Technology 89, no. 5 (September 4, 2017): 709–18. http://dx.doi.org/10.1108/aeat-01-2017-0013.

Повний текст джерела
Анотація:
Purpose The area behind the engine/wing junction of conventional civil aircraft configurations with underwing-mounted turbofans is susceptible to local flow separation at high angles of attack, which potentially impacts maximum lift performance of the aircraft. This paper aims to present the design, testing and optimization of two distinct systems of fluidic actuation dedicated to reduce separation at the engine/wing junction. Design/methodology/approach Active flow control applied at the unprotected leading edge inboard of the engine pylon has shown considerable potential to alleviate or even eliminate local flow separation, and consequently regain maximum lift performance. Two actuator systems, pulsed jet actuators with and without net mass flux, are tested and optimized with respect to an upcoming large-scale wind tunnel test to assess the effect of active flow control on the flow behavior. The requirements and parameters of the flow control hardware are set by numerical simulations of project partners. Findings The results of ground test show that full modulation of the jets of the non-zero mass flux actuator is achieved. In addition, it could be shown that the required parameters can be satisfied at design mass flow, and that pressure levels are within bounds. Furthermore, a new generation of zero-net mass flux actuators with improved performance is presented and described. This flow control system includes the actuator devices, their integration, as well as the drive and control electronics system that is used to drive groups of actuators. Originality/value The originality is given by the application of the two flow control systems in a scheduled large-scale wind tunnel test.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Wang, Ruichen, and Xun Huang. "Sound radiation from semi-infinite elliptical ducts with uniform subsonic jets: An analytical approach." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A188—A189. http://dx.doi.org/10.1121/10.0023221.

Повний текст джерела
Анотація:
This paper presents an analytical method for modeling the acoustic field radiation from a semi-infinite elliptical duct with a uniform subsonic jet. Elliptical ducts are often used as inlets for turbofan engines to take full advantage of the pre-compression effect of the fuselage and improve the stealth performance of the aircraft. The method accounts for the instability wave inside the vortex sheet induced by the shearing of jet and ambient flow and its effect to sound radiation. The method uses Mathieu functions to describe the incident and scattered sound in the elliptic cylindrical coordinates. A semi-analytical Wiener-Hopf approach with low computational cost is applied to obtain the near and far field solutions. The near field is illustrated by acoustic pressure maps at different modes and circumferential angles. The far field is shown by directivity patterns at single tones. Numerical simulations based on a finite element method are conducted to validate the accuracy of the analytical method. The results show good agreement between the analytical and numerical solutions. The proposed method can be used to analyze the acoustic characteristics of elliptical ducts with jets, which are relevant for noise control and optimization of turbofan engine inlets.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Shah, P. N., D. D. Mobed, and Z. S. Spakovszky. "A Novel Turbomachinery Air-Brake Concept for Quiet Aircraft." Journal of Turbomachinery 132, no. 4 (April 26, 2010). http://dx.doi.org/10.1115/1.3192145.

Повний текст джерела
Анотація:
A novel air-brake concept for next-generation, low-noise civil aircraft is introduced. Deployment of such devices in clean airframe configuration can potentially reduce aircraft source noise and noise propagation to the ground. The generation of swirling outflow from a duct, such as an aircraft engine, is demonstrated to have high drag and low noise. The simplest configuration is a ram pressure-driven duct with stationary swirl vanes, a so-called swirl tube. A detailed aerodynamic design is performed using first principles based modeling and high-fidelity numerical simulations. The swirl-drag-noise relationship is quantified through scale-model aerodynamic and aeroacoustic wind tunnel tests. The maximum measured stable flow drag coefficient is 0.83 at exit swirl angles close to 50 deg. The acoustic signature, extrapolated to full-scale, is found to be well below the background noise of a well-populated area. Vortex breakdown is found to be the aerodynamically and acoustically limiting phenomenon, generating a white-noise signature that is about 15 dB louder than a stable swirling flow.
Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Numerical optimization and civil aircraft engine noise"

1

Ezzine, Mouhamed Mounibe. "Etude de dispositifs passifs et actifs de réduction du bruit d’interaction soufflante–redresseur." Electronic Thesis or Diss., Ecully, Ecole centrale de Lyon, 2024. http://www.theses.fr/2024ECDL0022.

Повний текст джерела
Анотація:
Deux approches de diminution du bruit d'origine aéroacoustique associé à l'OGV des moteurs d'avion ont été examinées dans cette thèse. La première repose sur des solutions passives, utilisant des matériaux comme de la mousse poreuse et du tissu métallique (wire mesh) pour atténuer le bruit. L'efficacité de ces matériaux a été testée dans diverses configurations, montrant une capacité de réduction du bruit jusqu'à 6 dB sous certaines conditions, bien que cette efficacité puisse être affectée par des facteurs comme la vitesse de l'écoulement. La seconde partie de l'étude s'est intéressée aux techniques actives, notamment à l'utilisation de cellules piézoélectriques pour le contrôle du bruit. Ces technologies ont montré une réduction notable du bruit, atteignant jusqu'à 15 dB dans certains cas, bien qu'une amplification du bruit ait été notée dans d'autres situations, soulignant l'importance de la précision du design dans l'application de ces technologies. Enfin, l'optimisation numérique de l'impédance acoustique sur les profils aérodynamiques a été explorée, avec pour objectif de réduire davantage le bruit généré par les écoulements turbulents. Cette démarche a permis d'identifier des valeurs d'impédance optimales, conduisant à des réductions significatives de bruit pour certaines fréquences. Les résultats suggèrent qu'un choix précis de l'impédance acoustique sur les surfaces des profils peut être une méthode efficace pour minimiser le bruit d'origine aéroacoustique, bien que la géométrie du profil puisse influencer les résultats. Dans l'ensemble, ces études mettent en évidence le potentiel de différentes stratégies pour la réduction du bruit aéroacoustique, tout en soulignant la nécessité d'une application soigneuse et adaptée aux conditions spécifiques pour maximiser leur efficacité
Two approaches to reduce aeroacoustic noise associated with the OGV of aircraft engines have been examined in this thesis. The first relies on passive solutions, using materials such as porous foam and wire mesh to attenuate noise. The effectiveness of these materials has been tested in various configurations, demonstrating a noise reduction capacity of up to 6 dB under certain conditions, although this efficiency may be affected by factors such as flow velocity. The second part of the study focused on active techniques, particularly the use of piezoelectric cells for noise control. These technologies have shown a notable reduction in noise, reaching up to 15 dB in some cases, although noise amplification has been noted in other situations, emphasizing the importance of precise design in the application of these technologies. Finally, numerical optimization of acoustic impedance on aerodynamic profiles was explored, aiming to further reduce noise generated by turbulent flows. This approach identified optimal impedance values, leading to significant noise reductions for certain frequencies. The results suggest that precise selection of acoustic impedance on profile surfaces can be an effective method for minimizing aeroacoustic noise, although profile geometry may influence the results. Overall, these studies highlight the potential of different strategies for aeroacoustic noise reduction, while emphasizing the need for careful application tailored to specific conditions to maximize their effectiveness
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Numerical optimization and civil aircraft engine noise"

1

Igor, Egorov N., Kretinin V. Gennady, Leshchenko A. Igor, and Kuptzov V. Sergey. "Multi-Objective Robust Optimization of Air Engine Using IOSO Technology." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53504.

Повний текст джерела
Анотація:
This paper demonstrates the multi-objective optimization of air engine in aircraft system using either Deterministic or Robust Design Optimization statements. The goal is to obtain the Pareto-optimum frontier for the air engine and aircraft parameters. Performance characteristics of engine include the following: specific fuel consumption; thrust, with external resistance included, for any flight operating modes of aircraft; weight; the engine size parameters; engine’s life period; level of engine noise; and maintenance costs of the engine. Performance characteristics of an aircraft include passenger-per-kilometer fuel consumption, direct maintenance expenditures, maintenance cost, terrain noise level, take-off runway length, maximum flight altitude, maximum flight Mach number for different parameters of the operation process of the engine, and the various aircraft geometry parameters. While solving a problem of optimizing an engine in an aircraft system, conditions may exist where values of objective function and constraints can not be calculated. This can be caused by both the unfeasibility of a whole system for certain combinations of design variables, and the instability of numerical schemes used as mathematical models. Such conditions can even lead to a crash of the mathematical model. The existence of such areas usually substantially complicates the solution of optimization tasks and in some cases makes it impossible to find optimal solution. The paper illustrates that IOSO algorithms can deal with such cases very efficiently. This paper presents the result of the probabilistic statement of the multi-objective optimization problem, which decreases technical risks when developing modern objects and systems with the highest level of efficiency.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Carnevale, Mauro, Feng Wang, and Luca di Mare. "Low Frequency Distortion in Civil Aero-Engine Intake." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56203.

Повний текст джерела
Анотація:
The main role of the intake is to provide a sufficient mass flow to the engine face and sufficient flow homogeneity to the fan. Intake-fan interaction off design represents a critical issue in the design process because intake lines are set very early during the aircraft optimization. The off-design operation of an aero-engine, strictly related to the intake flow field, can be mainly related to two different conditions. When the plane is in near ground position, vorticity can be ingested by the fan due to crosswind incidence. During the flight, distortions occur due to incidence. In these conditions, the windward lip is subjected to high acceleration followed by strong adverse pressure gradients, high streamline curvature and cohabitation of incompressible and transonic flow around the lip. All these features increase the risk of lip stall in flight at incidence or in crosswind near ground operation and increase the level of forcing seen by the fan blades because of the interaction with non-uniform flow from the intake. This work deals with the study of two sources of distortions: ground vortex ingestion and flight at high incidence conditions. A test case representative of a current installation clearance from the ground has been investigated and the experimental data available in open literature validated the CFD approach. An intake, representative of a realistic civil aeroengine configuration flying at high incidence, has been investigated in powered and aspirated configurations. Distortion distributions have been characterized in terms of total loss distributions in space and in time. The beneficial effect of the presence of the fan in terms of distortion control has been demonstrated. The mutual effect between fan and incoming distortion from the intake has been assessed in terms of modal force and distortion control. CFD has been validated by means of comparisons between numerical results and experimental data have been provided. Waves predicted by CFD have been compared with an actuator disk approach prediction. The linear behavior of the lower disturbance frequency coming from distortion and the waves reflected by the fan has been demonstrated.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Shah, P. N., D. D. Mobed, and Z. S. Spakovszky. "A Novel Turbomachinery Air-Brake Concept for Quiet Aircraft." In ASME Turbo Expo 2007: Power for Land, Sea, and Air. ASMEDC, 2007. http://dx.doi.org/10.1115/gt2007-27635.

Повний текст джерела
Анотація:
A novel air-brake concept for next generation, low-noise civil aircraft is introduced. Deployment of such devices in clean airframe configuration reduces aircraft source noise and noise propagation to the ground. The generation of swirling outflow from a duct, such as an aircraft engine, is demonstrated to have high drag and low noise. The simplest configuration is a ram pressure driven duct with stationary swirl vanes, a so-called swirl tube. A detailed aerodynamic design is performed using first principles based modeling and high-fidelity numerical simulations. The swirl-drag-noise relationship is quantified through scale-model aerodynamic and aeroacoustic wind tunnel tests. The maximum measured stable flow drag coefficient is 0.83 at exit swirl angles close to 50 degrees. The acoustic signature, extrapolated to full-scale, is found to be well below the background noise of a well populated area. Vortex breakdown is found to be the aerodynamically and acoustically limiting physical phenomenon, generating a white-noise signature that is about 15 dB louder than a stable swirling flow.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Bartelt, Michael, Juan D. Laguna, and Joerg R. Seume. "Synthetic Sound Source Generation for Acoustical Measurements in Turbomachines." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95045.

Повний текст джерела
Анотація:
One of the greatest challenges in modern aircraft propulsion design is the reduction of the engine noise emission in order to develop quieter aircrafts. In the course of a current research project, the sound transport in low pressure turbines is investigated. For the corresponding experimental measurements, a specific acoustic excitation system is developed which can be implemented into the inlet of a turbine test rig and into an aeroacoustic wind tunnel. This allows for an acoustic mode generation and a synthesis of various sound source patterns to simulate typical turbomachinery noise sources such as rotor-stator interaction, etc. The paper presents the acoustical and technical design methodology in detail and addresses the experimental options of the system. Particular attention is paid to the design and the numerical optimization of the acoustic excitation units. To validate the sound generator during operation, measurements are performed in an aeroacoustic wind tunnel. For this purpose, an in-duct microphone array with a specific beamforming algorithm for hard-walled ducts is developed and applied to identify the source locations. The synthetically excited sound fields and the propagating acoustic modes are measured and analyzed by means of modal decomposition techniques. The measurement principles and the results are discussed in detail and it is shown that the intended sound source is produced and the intended sound field is excited. This paper shall contribute to help guide the development of excitation systems for aeroacoustic experiments to better understanding the physics of sound propagation within turbomachines.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Fiorio, M. "Hardware-in-the-loop validation of a sense and avoid system leveraging data fusion between radar and optical sensors for a mini UAV." In Aeronautics and Astronautics. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902813-16.

Повний текст джерела
Анотація:
Abstract. The present work illustrates the results obtained at the conclusion of the three-year project TERSA (Tecnologie Elettriche e Radar per Sapr Autonomi), involving the aerospace section of the Dept. of Civil and Industrial Engineering (DICI) of the University of Pisa and its industrial partners. The project aimed at the design and development of a fully autonomous Sense and Avoid (SAA) prototype system, based on data fusion between optical and radar sensors data, for a tactical lightweight surveillance UAV (MTOW<25Kg). The problem of non-cooperative collision avoidance is well known in literature and is currently a central theme of investigation within the aeronautical industry, considering the growing UAV traffic and the consequent need to employ autonomous self-separation technologies in the market. Several past works have investigated the most varied solutions for the Sense problem utilizing optical, acoustic, electro-magnetic signals or a combination of the previous. Likewise, the Avoidance problem has been successfully tackled in literature by means of a wide variety of different approaches ranging from rule-based methods, strategies based on game theory, force field methods, optimization frameworks leveraging genetic algorithms and nonlinear programming techniques and geometric methods. Yet, to the knowledge of the authors, no previous work found in literature has successfully demonstrated and validated the real-time simultaneous interaction of both sense and avoid functionalities within a highly integrated simulation environment. The present work describes the implementation of a complex, nonlinear, simulation environment conceived in order to perform real-time, Hardware-in-the-Loop (HIL), testing of the effective cooperation between sense and the avoid algorithms constituting the core of the SAA system developed within the context of the project. The system effectiveness has been validated by means of complex dynamic simulations, comprising an accurate, fully nonlinear, flight mechanic model of the aircraft, a graphic rendering engine of the scene, proper video capture and transmission pipelines, computer vision algorithms and collision avoidance logics running on the target hardware (Nvidia Jetson Nano) and tailored noise resilient data fusion algorithms. Results show the effectiveness of the system in detecting impending collisions and performing last-resort resolution manoeuvres with high computational efficiency and update frequencies compatible with real world applications in Unmanned Aircraft Systems (UAS).
Стилі APA, Harvard, Vancouver, ISO та ін.
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії