Airfoil Aeroacoustics, LES and Acoustic Analogy Predictions

Airfoil Aeroacoustics, LES and Acoustic Analogy Predictions
Author: William Roberto Wolf
Publisher: Stanford University
Total Pages: 238
Release: 2011
Genre:
ISBN:

The development of physics-based noise prediction tools for analysis of aerodynamic noise sources is of paramount importance since noise regulations have become more stringent. Direct simulation of aerodynamic noise remains prohibitively expensive for engineering problems because of the resolution requirements. Therefore, hybrid approaches that consist of predicting nearfield flow quantities by a suitable CFD simulation and farfield sound radiation by aeroacoustic integral methods are more attractive. In this work, we apply the fast multipole method (FMM) to accelerate the solution of boundary integral equation methods such as the boundary element method (BEM) and the Ffowcs Williams & Hawkings (FWH) acoustic analogy formulation. The FMM-BEM is implemented for the solution of acoustic scattering problems and the effects of non-uniform potential flows on acoustic scattering are investigated. The FMM-FWH is implemented for the solution of two and three-dimensional problems of sound propagation. The effects of flow convection and non-linear quadrupole sources are assessed through the study of sound generated by unsteady laminar flows. Finally, a hybrid methodology is applied for the investigation of airfoil noise. This study is important for the design of aerodynamic shapes such as wings and high-lift devices, as well as wind turbine blades, fans and propellers. The present investigation of airfoil self-noise generation and propagation concerns the broadband noise that arises from the interaction of turbulent boundary layers with the airfoil trailing edge and tonal noise that arises from vortex shedding generated by laminar boundary layers. Nearfield acoustic sources are computed using compressible large eddy simulation (LES) and acoustic predictions are performed by the FMM-FWH. Numerical simulations are conducted for a NACA0012 airfoil with tripped boundary layers and blunt rounded trailing edge at different Mach numbers and angles of incidence. The effects of non-linear quadrupole sources and convection are assessed. In order to validate the numerical solutions, flow simulation and acoustic prediction results are compared to experimental data available in the literature and excellent agreement is observed.

Proceedings of the International Conference on Aerospace System Science and Engineering 2019

Proceedings of the International Conference on Aerospace System Science and Engineering 2019
Author: Zhongliang Jing
Publisher: Springer Nature
Total Pages: 372
Release: 2020-02-29
Genre: Science
ISBN: 9811517738

This book presents the proceedings of the International Conference on Aerospace System Science and Engineering (ICASSE 2019), held in Toronto, Canada, on July 30–August 1, 2019, and jointly organized by the University of Toronto Institute for Aerospace Studies (UTIAS) and the Shanghai Jiao Tong University School of Aeronautics and Astronautics. ICASSE 2019 provided a forum that brought together experts on aeronautics and astronautics to share new ideas and findings. These proceedings present high-quality contributions in the areas of aerospace system science and engineering, including topics such as trans-space vehicle system design and integration, air vehicle systems, space vehicle systems, near-space vehicle systems, aerospace robotics and unmanned systems, communication, navigation and surveillance, aerodynamics and aircraft design, dynamics and control, aerospace propulsion, avionics systems, optoelectronic systems, and air traffic management.

Wind Farm Noise

Wind Farm Noise
Author: Colin H. Hansen
Publisher: John Wiley & Sons
Total Pages: 839
Release: 2017-01-31
Genre: Technology & Engineering
ISBN: 1118826124

A comprehensive guide to wind farm noise prediction, measurement, assessment, control and effects on people Wind Farm Noise covers all aspects associated with the generation, measurement, propagation, regulation and adverse health effects of noise produced by large horizontal-axis wind turbines of the type used in wind farms. The book begins with a brief history of wind turbine development and the regulation of their noise at sensitive receivers. Also included is an introductory chapter on the fundamentals of acoustics relevant to wind turbine noise so that readers are well prepared for understanding later chapters on noise measurements, noise generation mechanisms, noise propagation modelling and the assessment of the noise at surrounding residences. Key features: Potential adverse health effects of wind farm noise are discussed in an objective way. Means for calculating the noise at residences due to a wind farm prior to construction are covered in detail along with uncertainty estimates. The effects of meteorological conditions and other influences, such as obstacles, ground cover and atmospheric absorption, on noise levels at residences are explained. Quantities that should be measured as well as how to best measure them in order to properly characterise wind farm noise are discussed in detail. Noise generation mechanisms and possible means for their control are discussed as well as aspects of wind farm noise that still require further research to be properly understood. The book provides comprehensive coverage of the topic, containing both introductory and advanced level material.

Variational Analysis and Aerospace Engineering: Mathematical Challenges for Aerospace Design

Variational Analysis and Aerospace Engineering: Mathematical Challenges for Aerospace Design
Author: Giuseppe Buttazzo
Publisher: Springer Science & Business Media
Total Pages: 467
Release: 2012-04-23
Genre: Mathematics
ISBN: 1461424356

This volume consists of papers presented at the Variational Analysis and Aerospace Engineering Workshop II held in Erice, Italy in September 2010 at the International School of Mathematics "Guido Stampacchia". The workshop provided a platform for aerospace engineers and mathematicians (from universities, research centers and industry) to discuss the advanced problems requiring an extensive application of mathematics. The presentations were dedicated to the most advanced subjects in engineering and, in particular to computational fluid dynamics methods, introduction of new materials, optimization in aerodynamics, structural optimization, space missions, flight mechanics, control theory and optimization, variational methods and applications, etc. This book will capture the interest of researchers from both academia and industry.

Numerical Simulation of Wind Turbines

Numerical Simulation of Wind Turbines
Author: Alessandro Bianchini
Publisher: MDPI
Total Pages: 308
Release: 2021-09-10
Genre: Technology & Engineering
ISBN: 3036511652

The book contains the research contributions belonging to the Special Issue "Numerical Simulation of Wind Turbines", published in 2020-2021. They consist of 15 original research papers and 1 editorial. Different topics are discussed, from innovative design solutions for large and small wind turbine to control, from advanced simulation techniques to noise prediction. The variety of methods used in the research contributions testifies the need for a holistic approach to the design and simulation of modern wind turbines and will be able to stimulate the interest of the wind energy community.

The Aerodynamics of Heavy Vehicles III

The Aerodynamics of Heavy Vehicles III
Author: Andreas Dillmann
Publisher: Springer
Total Pages: 416
Release: 2015-08-19
Genre: Technology & Engineering
ISBN: 3319201220

This volume contains papers presented at the International conference “The Aerodynamics of Heavy Vehicles III: Trucks, Buses and Trains” held in Potsdam, Germany, September 12-17, 2010 by Engineering Conferences International (ECI). Leading scientists and engineers from industry, universities and research laboratories, including truck and high-speed train manufacturers and operators were brought together to discuss computer simulation and experimental techniques to be applied for the design of more efficient trucks, buses and high-speed trains in the future. This conference was the third in the series after Monterey-Pacific Groove in 2002 and Lake Tahoe in 2007.The presentations address different aspects of train aerodynamics (cross wind effects, underbody flow, tunnel aerodynamics and aeroacoustics, experimental techniques), truck aerodynamics (drag reduction, flow control, experimental and computational techniques) as well as computational fluid dynamics and bluff body, wake and jet flows.

Unsteady Computational Fluid Dynamics in Aeronautics

Unsteady Computational Fluid Dynamics in Aeronautics
Author: P.G. Tucker
Publisher: Springer Science & Business Media
Total Pages: 432
Release: 2013-08-30
Genre: Technology & Engineering
ISBN: 9400770499

The field of Large Eddy Simulation (LES) and hybrids is a vibrant research area. This book runs through all the potential unsteady modelling fidelity ranges, from low-order to LES. The latter is probably the highest fidelity for practical aerospace systems modelling. Cutting edge new frontiers are defined. One example of a pressing environmental concern is noise. For the accurate prediction of this, unsteady modelling is needed. Hence computational aeroacoustics is explored. It is also emerging that there is a critical need for coupled simulations. Hence, this area is also considered and the tensions of utilizing such simulations with the already expensive LES. This work has relevance to the general field of CFD and LES and to a wide variety of non-aerospace aerodynamic systems (e.g. cars, submarines, ships, electronics, buildings). Topics treated include unsteady flow techniques; LES and hybrids; general numerical methods; computational aeroacoustics; computational aeroelasticity; coupled simulations and turbulence and its modelling (LES, RANS, transition, VLES, URANS). The volume concludes by pointing forward to future horizons and in particular the industrial use of LES. The writing style is accessible and useful to both academics and industrial practitioners. From the reviews: "Tucker's volume provides a very welcome, concise discussion of current capabilities for simulating and modellng unsteady aerodynamic flows. It covers the various pos sible numerical techniques in good, clear detail and presents a very wide range of practical applications; beautifully illustrated in many cases. This book thus provides a valuable text for practicing engineers, a rich source of background information for students and those new to this area of Research & Development, and an excellent state-of-the-art review for others. A great achievement." Mark Savill FHEA, FRAeS, C.Eng, Professor of Computational Aerodynamics Design & Head of Power & Propulsion Sciences, Department of Power & Propulsion, School of Engineering, Cranfield University, Bedfordshire, U.K. "This is a very useful book with a wide coverage of many aspects in unsteady aerodynamics method development and applications for internal and external flows." L. He, Rolls-Royce/RAEng Chair of Computational Aerothermal Engineering, Oxford University, U.K. "This comprehensive book ranges from classical concepts in both numerical methods and turbulence modelling approaches for the beginner to latest state-of-the-art for the advanced practitioner and constitutes an extremely valuable contribution to the specific Computational Fluid Dynamics literature in Aeronautics. Student and expert alike will benefit greatly by reading it from cover to cover." Sébastien Deck, Onera, Meudon, France