Hybrid Wing-body Aircraft Noise and Performance Assessment


Book Description

Hybrid wing-body aircraft noise generation and boundary layer ingestion (BLI) performance trends with increased fan face Mach number inlet designs are investigated. The presented topics are in support of the NASA subsonic fixed wing project, which seeks to lower noise and increase performance by improving prediction methods and technologies. The aircraft configurations used for study are the N2A, using conventional podded engines, and the N2B, using an embedded propulsion system. Preliminary FAR Part 36 noise certification assessments are completed using the NASA Aircraft Noise Prediction Program (ANOPP). The limitations of applying current ANOPP noise prediction methods to hybrid wing-body aircraft are investigated. Improvements are made to the landing gear and airfoil self-noise modules, while a diffraction integral method is implemented in a companion thesis to enhance noise shielding estimates. The N2A overall takeoff and landing noise estimate is found to be 5.3 EPNdB higher than the N+2 goal. The dominant noise sources are the fan rearward and jet on takeoff and the main landing gear and elevons on approach. A lower fan pressure ratio and advanced landing gear fairings are recommended to decrease N2A overall noise levels. The available engine noise estimation tools were inadequate to model the N2B distributed propulsion system and rectangular exhaust nozzle; therefore, overall N2B aircraft noise results are presented for reference only. A simplified embedded propulsion system integration study is carried out to explore the N2B fan design space. A 2-D computational domain with contoured slip boundaries around the centerbody is used to replicate the effects of 3-D relief on the airframe and inlet aerodynamics. The domain includes the S-shaped inlet duct and is extended far downstream for a Trefftz plane power balance analysis to determine the propulsive power required for steady level flight. A fan actuator volume is included to couple the airframe external and the engine internal flows. Aircraft power savings, fan efficiency, and boundary layer thickness trends are examined to determine if increasing fan face Mach number improves system performance while mitigating the total pressure distortion risk of boundary layer ingestion. A fan face Mach number near 0.7 is found to increase aircraft power savings 12% relative to the baseline design and to reduce centerbody boundary layer kinetic energy thickness by 4.7%. In addition, power balances at lower fan pressure ratios as fan face Mach number increases suggesting that high-flow low pressure ratio fans are desirable for BLI.




Aircraft Noise


Book Description

Aircraft noise has adverse impacts on passengers, airport staff and people living near airports, it thus limits the capacity of regional and international airports throughout the world. Reducing perceived noise of aircraft involves reduction of noise at source, along the propagation path and at the receiver. Effective noise control demands highly skilled and knowledgeable engineers. This book is for them. It shows you how accurate and reliable information about aircraft noise levels can be gained by calculations using appropriate generation and propagation models, or by measurements with effective monitoring systems. It also explains how to allow for atmospheric conditions, natural and artificial topography as well as detailing necessary measurement techniques.




Status of Hybrid Wing Body Community Noise Assessments


Book Description

The NASA Technical Reports Servcr (NTRS) houses half a million publications that are a valuable means of information to researchers, teachers, students, and the general public. These documents are all aerospace related with much scientific and technical information created or funded by NASA. Some types of documents include conference papers, research reports, meeting papers, journal articles and more. This is one of those documents.




Aviation Noise Impact Management


Book Description

This open access book provides a view into the state-of-the-art research on aviation noise and related annoyance. The book will primarily focus on the achievements of the ANIMA project (Aviation Noise Impact Management through Novel Approaches), but not exclusively. The content has a broader theme in order to encompass. regulation issues, the ICAO (International Civil Aviation Organization) balanced approach, progresses made on technologies and reduction of noise at source, impact of possible future civil supersonic aircraft, land-use planning issues, as well as the core topics of the ANIMA project, i.e. impact on human beings, annoyance, quality of life, health and findings of the project in this respect. This book differs from traditional research programmes on aviation noise as the authors endeavour, not to lower noise at source, but to reduce the annoyance. This book examines these non-acoustic factors in an effort to help those most affected by aviation noise – communities living close to airports, and also help airport managers, policy-makers, local authorities and researchers to deal with this issue holistically. The book concludes with some recommendations for EU, national and local policy-makers, airport and aviation authorities, and more broadly a scientifically literate audience. These recommendations may help to identify gaps for progress in terms of research but also genuine implementation actions for political and regulatory authorities.




Design and Acoustic Shielding Prediction of Hybrid Wing-body Aircraft


Book Description

(Cont.) At the same time, high fidelity methods such as boundary element methods and ray tracing methods are too computationally expensive if used in the early aircraft design and assessment stage. A compromise is the previously formulated diffraction integral concept based on the Maggi-Rubinowicz representation of Kirchhoff's diffraction theory. The diffraction integral method was implemented and applied to the N2A and the N2B aircraft. A noise reduction of over 20 dB in OASPL due to airframe shielding was predicted, demonstrating the shielding benefit of the HWB configuration. This shielding method is shown to be applicable to any aircraft configuration and planform geometry. The contributions of this thesis are the design of an HWB aircraft to be used as a platform for the development and evaluation of advanced analysis methods. In addition, a fast and improved-fidelity method for noise shielding prediction was developed, applicable to conventional and advanced airframe configurations such as, for example, the N2A and the N2B HWB aircraft.







Beyond Tube-and-Wing


Book Description




Modeling and Control for a Blended Wing Body Aircraft


Book Description

This book demonstrates the potential of the blended wing body (BWB) concept for significant improvement in both fuel efficiency and noise reduction and addresses the considerable challenges raised for control engineers because of characteristics like open-loop instability, large flexible structure, and slow control surfaces. This text describes state-of-the-art and novel modeling and control design approaches for the BWB aircraft under consideration. The expert contributors demonstrate how exceptional robust control performance can be achieved despite such stringent design constraints as guaranteed handling qualities, reduced vibration, and the minimization of the aircraft’s structural loads during maneuvers and caused by turbulence. As a result, this innovative approach allows the building of even lighter aircraft structures, and thus results in considerable efficiency improvements per passenger kilometer. The treatment of this large, complex, parameter-dependent industrial control problem highlights relevant design issues and provides a relevant case study for modeling and control engineers in many adjacent disciplines and applications. Modeling and Control for a Blended Wing Body Aircraft presents research results in numeric modeling and control design for a large, flexible, civil BWB aircraft in the pre-design stage as developed within the EU FP7 research project ACFA 2020. It is a useful resource for aerospace and control engineers as it shows the complete BWB aircraft modeling and control design process, carried out with the most recent tools and techniques available. presents research results in numeric modeling and control design for a large, flexible, civil BWB aircraft in the pre-design stage as developed within the EU FP7 research project ACFA 2020. It is a useful resource for aerospace and control engineers as it shows the complete BWB aircraft modeling and control design process, carried out with the most recent tools and techniques available. Advances in Industrial Control aims to report and encourage the transfer of technology in control engineering. The rapid development of control technology has an impact on all areas of the control discipline. The series offers an opportunity for researchers to present an extended exposition of new work in all aspects of industrial control.




Green Aviation


Book Description

Green Aviation is the first authoritative overview of both engineering and operational measures to mitigate the environmental impact of aviation. It addresses the current status of measures to reduce the environmental impact of air travel. The chapters cover such items as: Engineering and technology-related subjects (aerodynamics, engines, fuels, structures, etc.), Operations (air traffic management and infrastructure) Policy and regulatory aspects regarding atmospheric and noise pollution. With contributions from leading experts, this volume is intended to be a valuable addition, and useful resource, for aerospace manufacturers and suppliers, governmental and industrial aerospace research establishments, airline and aviation industries, university engineering and science departments, and industry analysts, consultants, and researchers.




Sustainable Aviation Technology and Operations


Book Description

Sustainable Aviation Technology and Operations Comprehensively covers research and development initiatives to enhance the environmental sustainability of the??aviation sector Sustainable Aviation Technology and Operations provides a comprehensive and timely outlook of recent research advances in aeronautics and air transport, with emphasis on both long-term sustainable development goals and current achievements. This book discusses some of the most promising advances in aircraft technologies, air traffic management and systems engineering methodologies for sustainable aviation. The topics covered include: propulsion, aerodynamics, avionics, structures, materials, airspace management, biofuels and sustainable lifecycle management. The physical processes associated with various aircraft emissions — including air pollutants, noise and contrails — are presented to support the development of computational models for aircraft design, flight path optimization and environmental impact assessment. Relevant advances in systems engineering and lifecycle management processes are also covered, bridging some of the existing gaps between academic research and industry best practices. A collection of research case studies complements the book, highlighting opportunities for a timely uptake of the most promising technologies, towards a more efficient and environmentally sustainable aviation future. Key features: Contains important research and industry relevant contributions from world-class experts. Addresses recent advances in aviation sustainability including multidisciplinary design approaches and multi-objective operational optimisation methods. Includes a number of research case studies, addressing propulsion, aerostructures, alternative aviation fuels, avionics, air traffic management, and sustainable lifecycle management solutions. Sustainable Aviation Technology and Operations is an excellent book for aerospace engineers, aviation scientists, researchers and graduate students involved in the field.