Download or read book Airfoil Self noise and Prediction written by Thomas F. Brooks and published by . This book was released on 1989 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Airfoil Self Noise and Prediction written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: A prediction method is developed for the self-generated noise of an airfoil blade encountering smooth flow. The prediction methods for the individual self-noise mechanisms are semiempirical and are based on previous theoretical studies and data obtained from tests of two- and three-dimensional airfoil blade sections. The self-noise mechanisms are due to specific boundary-layer phenomena, that is, the boundary-layer turbulence passing the trailing edge, separated-boundary-layer and stalled flow over an airfoil, vortex shedding due to laminar boundary layer instabilities, vortex shedding from blunt trailing edges, and the turbulent vortex flow existing near the tip of lifting blades. The predictions are compared successfully with published data from three self-noise studies of different airfoil shapes. An application of the prediction method is reported for a large scale-model helicopter rotor, and the predictions compared well with experimental broadband noise measurements. A computer code of the method is given. Brooks, Thomas F. and Pope, D. Stuart and Marcolini, Michael A. Langley Research Center AEROACOUSTICS; AERODYNAMIC NOISE; AIRFOIL PROFILES; AIRFOILS; BLADE-VORTEX INTERACTION; BOUNDARY LAYER SEPARATION; BOUNDARY LAYERS; NOISE PREDICTION (AIRCRAFT); VORTEX SHEDDING; AERODYNAMIC STALLING; APPLICATIONS PROGRAMS (COMPUTERS); NOISE MEASUREMENT; NOISE SPECTRA; ROTARY WINGS; STROUHAL NUMBER; TRAILING EDGES; VORTICES; WIND TUNNEL TESTS...
Download or read book NASA Reference Publication written by and published by . This book was released on 1977 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1990 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Turbine Airfoils and Blades written by Jin Chen and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-12-04 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Turbine Airfoils and Blades introduces new ideas in the design of wind turbine airfoils and blades based on functional integral theory and the finite element method, accompanied by results from wind tunnel testing. The authors also discuss the optimization of wind turbine blades as well as results from aerodynamic analysis. This book is suitable for researchers and engineers in aeronautics and can be used as a textbook for graduate students.
Download or read book Airfoil Aeroacoustics LES and Acoustic Analogy Predictions written by William Roberto Wolf and published by Stanford University. This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Predicting Outdoor Sound written by Keith Attenborough and published by CRC Press. This book was released on 2021-03-07 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of Predicting Outdoor Sound is an up-to-date reference on the propagation of sound close to the ground and its prediction. New content includes comparisons between predictions and data for road traffic, railway and wind turbine noise; descriptions of source characteristics in the HARMONOISE model; propagation over rough seas, parallel low walls, and lattices; outlines of numerical methods; gabion (caged stones) and sonic crystal noise barriers; meteorological effects on noise barrier performance; and the prediction requirements for auralization. The book brings together relevant theories, prediction schemes, and data, thereby providing a basis for determining what model or scheme might be applicable for any situation. It also offers a background on useful analytical approximations and the restrictions, as well as difficulties and limitations associated with engineering prediction schemes. The text should be of considerable interest to researchers in outdoor sound propagation and, more generally, it should provide a comprehensive primer on the topic for lecturers, consultants and students in acoustics and noise control.
Download or read book Wind Turbine Aerodynamics written by Wen Zhong Shen and published by MDPI. This book was released on 2019-10-04 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine aerodynamics is one of the central subjects of wind turbine technology. To reduce the levelized cost of energy (LCOE), the size of a single wind turbine has been increased to 12 MW at present, with further increases expected in the near future. Big wind turbines and their associated wind farms have many advantages but also challenges. The typical effects are mainly related to the increase in Reynolds number and blade flexibility. This Special Issue is a collection of 21 important research works addressing the aerodynamic challenges appearing in such developments. The 21 research papers cover a wide range of problems related to wind turbine aerodynamics, which includes atmospheric turbulent flow modeling, wind turbine flow modeling, wind turbine design, wind turbine control, wind farm flow modeling in complex terrain, wind turbine noise modeling, vertical axis wind turbine, and offshore wind energy. Readers from all over the globe are expected to greatly benefit from this Special Issue collection regarding their own work and the goal of enabling the technological development of new environmentally friendly and cost-effective wind energy systems in order to reach the target of 100% energy use from renewable sources, worldwide, by 2050
Download or read book Advanced Applications in Acoustics Noise and Vibration written by Frank Fahy and published by CRC Press. This book was released on 2018-09-03 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Applications in Acoustics, Noise and Vibration provides comprehensive and up-to-date overviews of knowledge, applications and research activities in a range of topics that are of current interest in the practice of engineering acoustics and vibration technology. The thirteen chapters are grouped into four parts: signal processing, acoustic modelling, environmental and industrial acoustics, and vibration. Following on from its companion volume Fundamentals of Noise and Vibration this book is based partly on material covered in a selection of elective modules in the second semester of the Masters programme in 'Sound and Vibration Studies' of the Institute of Sound and Vibration Research at the University of Southampton, UK and partly on material presented in the annual ISVR short course 'Advanced Course in Acoustics, Noise and Vibration'.
Download or read book New Results in Numerical and Experimental Fluid Mechanics XIII written by Andreas Dillmann and published by Springer Nature. This book was released on 2021-07-13 with total page 787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers timely insights into research on numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications. It reports on findings by members of the STAB (German Aerospace Aerodynamics Association) and DGLR (German Society for Aeronautics and Astronautics) and covers both nationally and EC-funded projects. Continuing on the tradition of the previous volumes, the book highlights innovative solutions, promoting translation from fundamental research to industrial applications. It addresses academics and professionals in the field of aeronautics, astronautics, ground transportation, and energy alike.
Download or read book Advances in Mechanical Engineering and Material Science written by Pankaj Tambe and published by Springer Nature. This book was released on 2023-10-16 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the Second International Conference on Advances in Mechanical Engineering and Material Science (ICAMEMS 2023). It covers the latest research in broad areas of manufacturing and materials engineering. Various topics covered in this book are advanced manufacturing processes, additive manufacturing, green manufacturing, industry 4.0, conventional machining processes, non-conventional machining processes, micro machining, materials processing surface science and engineering, advanced composite materials, materials characterization, and many more. The book is useful for researchers and students in the various fields of mechanical engineering.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Optimization 2014 written by Hélder Rodrigues and published by CRC Press. This book was released on 2014-09-26 with total page 1078 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimization methodologies are fundamental instruments to tackle the complexity of today's engineering processes. Engineering Optimization 2014 is dedicated to optimization methods in engineering, and contains the papers presented at the 4th International Conference on Engineering Optimization (ENGOPT2014, Lisbon, Portugal, 8-11 September 2014). The book will be of interest to engineers, applied mathematicians, and computer scientists working on research, development and practical applications of optimization methods in engineering.
Download or read book Proceedings of the 2nd International Seminar on Aeronautics and Energy written by Nik Ahmad Ridhwan Nik Mohd. and published by Springer Nature. This book was released on 2023-12-20 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of selected peer-reviewed papers from the 2nd International Seminar on Aeronautics and Energy (ISAE 2022) focusing on the theme to revive the aviation industry post-COVID-19 pandemic. The topics discussed in this book include aircraft design and optimization, computational fluid dynamics (CFD) simulation and experimental aerodynamics, aircraft structure and aeroelasticity, guidance control and navigation, aircraft manufacturing and health monitoring avionics and system integration of UAV/drones, SITL AND HITL application on drones, rockets and missile, industrial wind engineering, green fuel and aviation sustainability, and aviation management. This book is a valuable resource for academicians and industry players in the field of aviation and sustainability.
Download or read book Aeroacoustics of Low Mach Number Flows written by Stewart Glegg and published by Elsevier. This book was released on 2023-09-26 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeroacoustics of Low Mach Number Flows: Fundamentals, Analysis and Measurement, Second Edition provides a detailed introduction to sound radiation from subsonic flow over moving surfaces. This phenomenon is the most widespread cause of flow noise in engineering systems, including fan noise, rotor noise, wind turbine noise, boundary layer noise, airframe noise and aircraft noise. This fully updated new edition includes additional problems, illustrations and summary materials to support readers. New content covers Rapid Distortion theory (RDT), boundary layer wall pressure fluctuations, and flow induced sound at surfaces. Themes addressing non-compressible flows have also been added, offering coverage of hydroacoustic as well as aeroacoustic applications. New support materials for this edition include course outlines, problem sets, sample MATLAB codes and experimental data to be found at www.aeroacoustics.net. - Addresses, in detail, sound from rotating blades, ducted fans, airframes, boundary layers, and more - Presents theory in such a way that it can be used in computational methods and calculating sound levels - Includes coverage of different experimental approaches to this subject
Download or read book New Results in Numerical and Experimental Fluid Mechanics IX written by Andreas Dillmann and published by Springer Science & Business Media. This book was released on 2014-01-25 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents contributions to the 18th biannual symposium of the German Aerospace Aerodynamics Association (STAB). The individual chapters reflect ongoing research conducted by the STAB members in the field of numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications, and cover both nationally and EC-funded projects. By addressing a number of essential research subjects, together with their related physical and mathematics fundamentals, the book provides readers with a comprehensive overview of the current research work in the field, as well as its main challenges and new directions. Current work on e.g. high aspect-ratio and low aspect-ratio wings, bluff bodies, laminar flow control and transition, active flow control, hypersonic flows, aeroelasticity, aeroacoustics and biofluid mechanics is exhaustively discussed here.
Download or read book Wind Power Generation and Wind Turbine Design written by Wei Tong and published by WIT Press. This book was released on 2010-04-30 with total page 769 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to provide engineers and researchers in both the wind power industry and energy research community with comprehensive, up-to-date, and advanced design techniques and practical approaches. The topics addressed in this book involve the major concerns in the wind power generation and wind turbine design.
