Aeroacoustics of Low Mach Number Flows : Fundamentals, Analysis and Measurement

• Autore: Glegg Stewart
• Pubblicazione: San Diego : , : Elsevier Science & Technology, , 2023; ©2024
• Edizione: 2nd ed.
• Descrizione fisica: 1 online resource (724 pages)
• Disciplina: 629.1323
• Soggetto topico: Aeroacoustics; Fluid dynamics
• Altri autori: DevenportWilliam
• Nota di contenuto: Intro -- Aeroacoustics of Low Mach Number Flows: Fundamentals, Analysis and Measurement -- Copyright -- Dedication -- Contents -- Preface to first edition -- Preface to second edition -- Part One: Fundamentals -- Chapter 1: Introduction -- 1.1. Aeroacoustics of low Mach number flows -- 1.2. Sound waves and turbulence -- 1.3. Quantifying sound levels and annoyance -- 1.4. Symbol and analysis conventions -- 1.5. Organization of the book -- 1.6. Problems -- References -- Chapter 2: The equations of fluid motion -- 2.1. Mathematical notation and foundations -- 2.2. The equation of continuity -- 2.3. The momentum equation -- 2.3.1. General considerations -- 2.3.2. Viscous stresses -- 2.4. Thermodynamic quantities -- 2.5. The role of vorticity -- 2.5.1. Croccos equation -- 2.5.2. The vorticity equation -- 2.6. Energy and acoustic intensity -- 2.6.1. The energy equation -- 2.6.2. Sound power -- 2.7. Some relevant fluid dynamic concepts and methods -- 2.7.1. Streamlines and vorticity -- 2.7.2. Ideal flow -- 2.7.3. Conformal mapping -- 2.7.4. Vortex filaments and the Biot Savart law -- 2.8. Summary of key results -- 2.9. Problems -- References -- Chapter 3: Linear acoustics -- 3.1. The acoustic wave equation -- 3.2. Plane waves and spherical waves -- 3.3. Harmonic time dependence -- 3.4. Sound generation by small bodies in motion -- 3.4.1. Pulsating sphere -- 3.4.2. Translating sphere -- 3.4.3. General spherical surface motions -- 3.5. Sound scattering by a small sphere -- 3.6. Superposition and far field approximations -- 3.7. Monopole, dipole and quadrupole sources -- 3.8. Acoustic intensity and sound power output -- 3.9. Solution to the wave equation using Greens functions -- 3.9.1. Spherical surfaces -- 3.10. Frequency domain solutions and Fourier transforms -- 3.11. Summary of key results -- 3.12. Problems -- References. ; Part Two: Foundations of aeroacoustics -- Chapter 4: Lighthills acoustic analogy -- 4.1. Lighthills analogy -- 4.2. Limitations of the acoustic analogy -- 4.2.1. Nearly incompressible flow -- 4.2.2. Uniform flow -- 4.3. Curles theorem -- 4.4. Monopole, dipole and quadrupole sources -- 4.5. Tailored Greens functions -- 4.6. Surfaces and sources -- 4.6.1. Boundary layers -- 4.6.2. The surface source for bodies immersed in a flow -- 4.7. Wavenumber and Fourier transforms -- 4.8. Summary of key results -- 4.9. Problems -- References -- Chapter 5: The Ffowcs Williams and Hawkings equation -- 5.1. Generalized derivatives -- 5.2. The Ffowcs Williams and Hawkings equation -- 5.2.1. General theory -- 5.2.2. Impenetrable surfaces -- 5.3. Moving sources -- 5.4. Sources in a free stream -- 5.5. The Prantl-Glauert transformation -- 5.6. Ffowcs Williams and Hawkings surfaces -- 5.7. Incompressible flow estimates of acoustic source terms -- 5.8. Summary of key results -- 5.9. Problems -- References -- Chapter 6: Propeller and open rotor noise -- 6.1. Tone and broadband noise -- 6.2. Time domain prediction methods for tone noise from a single rotor blade -- 6.2.1. Loading noise -- 6.2.2. Thickness noise -- 6.2.3. Supersonic tip speeds -- 6.3. Frequency domain prediction methods for tone noise -- 6.3.1. Harmonic analysis of loading and thickness noise -- 6.3.2. Rotor Stator interactions -- 6.4. Amiets approximation for small scale disturbances -- 6.5. Blade vortex interactions -- 6.6. Summary of key results -- 6.6.1. Loading noise in the time domain -- 6.6.2. Thickness noise in the time domain -- 6.6.3. Frequency domain methods for tone noise -- 6.6.4. Amiets approximation -- 6.7. Problems -- References -- Part Three: Unsteady blade loading -- Chapter 7: Amiets approach-The surface source for thin airfoils -- 7.1. Amiets approach. ; 7.2. The incompressible flow blade response function -- 7.3. The compressible flow blade response function -- 7.3.1. The compressible and incompressible flow blade response to a step gust -- 7.3.2. Leading and trailing edge solutions -- 7.3.3. The first-order solution for the surface pressure -- 7.3.4. The unsteady lift in compressible flow -- 7.3.5. An arbitrary gust -- 7.4. The acoustic far field -- 7.4.1. The acoustic far field from the leading edge interaction -- 7.4.2. The far field directionality and scaling -- 7.4.3. Impulsive gusts of finite span -- 7.4.4. A step gust -- 7.5. Blade vortex interactions in compressible flow -- 7.5.1. The upwash velocity spectrum from a blade vortex interaction -- 7.6. Summary of key results -- 7.7. Problems -- References -- Chapter 8: Goldsteins approach-Flows with distortion -- 8.1. Goldsteins equation -- 8.2. Drift coordinates -- 8.3. Rapid distortion theory -- 8.4. The rapid distortion of vorticity -- 8.5. Summary of key results -- 8.6. Problems -- References -- Chapter 9: Howes and Powells approach-Vortex sound -- 9.1. Theory of vortex sound -- 9.2. Sound from two line vortices in free space -- 9.3. Surface forces in incompressible flow -- 9.4. Aeolian tones -- 9.5. Blade vortex interactions in incompressible flow -- 9.5.1. Unsteady blade loading caused by a BVI -- 9.5.2. The far-field sound -- 9.5.3. Response to a step gust -- 9.6. The effect of angle of attack and blade thickness on unsteady loads -- 9.6.1. The effect of angle of attack -- 9.6.2. The effect of airfoil thickness -- 9.7. RDT and airfoil loading noise -- 9.8. Summary of key results -- 9.9. Problems -- References -- Part Four: Turbulent flows -- Chapter 10: Stochastic processes -- 10.1. Averaging and the expected value -- 10.2. Time correlations and frequency spectra of a single variable. ; 10.3. Time correlations and frequency spectra of two variables -- 10.4. Spatial correlation and the wavenumber spectrum -- 10.5. Summary of key results -- 10.6. Problems -- Reference -- Chapter 11: Turbulence and turbulent flows -- 11.1. The nature of turbulence -- 11.2. Averaging of the governing equations and computational approaches -- 11.3. Homogeneous isotropic turbulence -- 11.3.1. Mathematical description -- 11.3.2. The von Kármán spectrum -- 11.3.3. The Liepmann spectrum -- 11.3.4. The Kerschen Gliebe anisotropic model -- 11.4. The fully developed plane wake -- 11.5. The zero pressure gradient turbulent boundary layer -- 11.6. Rapid distortion theory and turbulence -- 11.7. Surface blocking -- 11.8. Summary of key results -- 11.9. Problems -- References -- Chapter 12: Wall pressure fluctuations in turbulent boundary layers -- 12.1. The frequency spectrum -- 12.2. The wavenumber frequency spectrum -- 12.3. The Poisson equation for wall pressure -- 12.4. Kraichnans integration -- 12.5. Modeling of the mean-shear-turbulence term -- 12.6. Summary of key results -- 12.7. Problems -- References -- Part Five: Broadband flow noise from surface interactions and fans -- Chapter 13: Broadband noise from open rotors and leading edge noise -- 13.1. Broadband noise from open rotors in general -- 13.1.1. Introduction -- 13.1.2. The frequency domain approach -- 13.1.3. Amiets method -- 13.1.4. Time domain approaches -- 13.2. An airfoil in a turbulent stream -- 13.3. Blade to blade correlation and haystacking -- 13.4. Summary of key results -- 13.5. Problems -- References -- Further reading -- Chapter 14: Trailing edge noise and roughness noise -- 14.1. The origin and scaling of trailing edge noise -- 14.2. Amiets trailing edge noise theory -- 14.3. The method of Brooks, Pope and Marcolini [8] -- 14.4. Roughness noise -- 14.5. Summary of key results. ; 14.6. Problems -- References -- Chapter 15: Duct acoustics -- 15.1. Introduction -- 15.2. The sound in a cylindrical duct -- 15.2.1. General formulation -- 15.2.2. Hard-walled ducts -- 15.2.3. Modal propagation -- 15.3. Duct liners -- 15.4. The Greens function for a source in a cylindrical duct -- 15.5. Sound power in ducts -- 15.6. Non-uniform mean flow -- 15.7. The radiation from duct inlets and exits -- 15.8. Summary of key results -- 15.9. Problems -- References -- Chapter 16: Fan noise -- 16.1. Sources of sound in ducted fans -- 16.2. Duct mode amplitudes -- 16.2.1. Thickness noise for a ducted fan -- 16.2.2. Blade loading noise -- 16.2.3. Fan tone noise -- 16.2.4. In duct sound power -- 16.3. The cascade blade response function -- 16.3.1. The rectilinear cascade model -- 16.3.2. The acoustic duct modes -- 16.3.3. The acoustic modes from an arbitrary gust -- 16.3.4. The sound power spectrum -- 16.4. The rectilinear model of a rotor or stator in a cylindrical duct -- 16.4.1. Mode matching -- 16.4.2. An axial dipole example -- 16.5. Wake evolution in swirling flows -- 16.6. Fan tone noise -- 16.6.1. The upwash coefficients -- 16.6.2. Unskewed self-similar wakes -- 16.7. Broadband fan noise -- 16.8. Summary of key results -- 16.8.1. Ducted fan noise -- 16.8.2. The sound generated by a cascade of blades -- 16.9. Problems -- References -- Part Six: Experimental methods -- Chapter 17: Aeroacoustic testing and instrumentation -- 17.1. Aeroacoustic wind tunnels -- 17.2. Wind tunnel acoustic corrections -- 17.2.1. Shear layer refraction -- 17.2.2. Corrections for a two-dimensional planar jet -- 17.2.3. Effects of shear layer thickness and curvature -- 17.2.4. Considerations for hybrid anechoic tunnels -- 17.3. Sound measurement -- 17.4. The measurement of turbulent pressure fluctuations -- 17.5. Velocity measurement -- 17.6. Summary of key results. ; 17.7. Problems.
• Sommario/riassunto: Aeroacoustics of Low Mach Number Flows, Second Edition, by Stewart Glegg and William Devenport, delves into the principles and methodologies of aeroacoustics, focusing on flows with low Mach numbers. The book provides a comprehensive exploration of the fundamental equations of fluid motion, linear acoustics, and the generation of sound by various sources. It discusses advanced topics such as Lighthill's acoustic analogy, the Ffowcs Williams and Hawkings equation, and the noise generated by propellers and rotors. The text is designed for researchers and practitioners in the field of aeroacoustics, offering detailed theoretical insights and practical measurement techniques. This edition emphasizes the latest advancements in the field and includes extensive references for further study.
• Titolo autorizzato: Aeroacoustics of Low Mach Number Flows
• ISBN: 9780443218583; 0443218587
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Lingua di pubblicazione: Inglese
• Record Nr.: 9911034971903321
• Lo trovi qui: Univ. Federico II