Aeroacoustics of Low Mach Number Flows: Fundamentals, Analysis, and Measurement provides a comprehensive treatment of sound radiation from subsonic flow over moving surfaces, which is the most widespread cause of flow noise in engineering systems. This includes fan noise, rotor noise, wind turbine noise, boundary layer noise, and aircraft noise.
Beginning with fluid dynamics, the fundamental equations of aeroacoustics are derived and the key methods of solution are explained, focusing both on the necessary mathematics and physics. Fundamentals of turbulence and turbulent flows, experimental methods and numerous applications are also covered.
The book is an ideal source of information on aeroacoustics for researchers and graduate students in engineering, physics, or applied math, as well as for engineers working in this field.
Author(s): Stewart Glegg, William Devenport
Publisher: Academic Press Elsevier
Year: 2017
Language: English
Pages: 0
Tags: Aeroacoustics, Acoustics, Fluid Mechanics, Fluid Dynamics, Sound, Noise
Part 1: Fundamentals
1: Introduction
Abstract
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 used in this book
2: The equations of fluid motion
Abstract
2.1 Tensor notation
2.2 The equation of continuity
2.3 The momentum equation
2.4 Thermodynamic quantities
2.5 The role of vorticity
2.6 Energy and acoustic intensity
2.7 Some relevant fluid dynamic concepts and methods
3: Linear acoustics
Abstract
3.1 The acoustic wave equation
3.2 Plane waves and spherical waves
3.3 Harmonic time dependence
3.4 Sound generation by a small sphere
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 Green's functions
3.10 Frequency domain solutions and Fourier transforms
4: Lighthill's acoustic analogy
Abstract
4.1 Lighthill's analogy
4.2 Limitations of the acoustic analogy
4.3 Curle's theorem
4.4 Monopole, dipole, and quadrupole sources
4.5 Tailored Green's functions
4.6 Integral formulas for tailored Green's functions
4.7 Wavenumber and Fourier transforms
5: The Ffowcs Williams and Hawkings equation
Abstract
5.1 Generalized derivatives
5.2 The Ffowcs Williams and Hawkings equation
5.3 Moving sources
5.4 Sources in a free stream
5.5 Ffowcs Williams and Hawkings surfaces
5.6 Incompressible flow estimates of acoustic source terms
6: The linearized Euler equations
Abstract
6.1 Goldstein's equation
6.2 Drift coordinates
6.3 Rapid distortion theory
6.4 Acoustically compact thin airfoils and the Kutta condition
6.5 The Prantl–Glauert transformation
7: Vortex sound
Abstract
7.1 Theory of vortex sound
7.2 Sound from two line vortices in free space
7.3 Surface forces in incompressible flow
7.4 Aeolian tones
7.5 Blade vortex interactions in incompressible flow
7.6 The effect of angle of attack and blade thickness on unsteady loads
8: Turbulence and stochastic processes
Abstract
8.1 The nature of turbulence
8.2 Averaging and the expected value
8.3 Averaging of the governing equations and computational approaches
8.4 Descriptions of turbulence for aeroacoustic analysis
9: Turbulent flows
Abstract
9.1 Homogeneous isotropic turbulence
9.2 Inhomogeneous turbulent flows
Part 2: Experimental approaches
10: Aeroacoustic testing and instrumentation
Abstract
10.1 Aeroacoustic wind tunnels
10.2 Wind tunnel acoustic corrections
10.3 Sound measurement
10.4 The measurement of turbulent pressure fluctuations
10.5 Velocity measurement
11: Measurement, signal processing, and uncertainty
Abstract
11.1 Limitations of measured data
11.2 Uncertainty
11.3 Averaging and convergence
11.4 Numerically estimating fourier transforms
11.5 Measurement as seen from the frequency domain
11.6 Calculating time spectra and correlations
11.7 Wavenumber spectra and spatial correlations
12: Phased arrays
Abstract
12.1 Basic delay and sum processing
12.2 General approach to array processing
12.3 Deconvolution methods
12.4 Correlated sources and directionality
Part 3: Edge and boundary layer noise
13: The theory of edge scattering
Abstract
13.1 The importance of edge scattering
13.2 The Schwartzschild problem and its solution based on the Weiner Hopf method
13.3 The effect of uniform flow
13.4 The leading edge scattering problem
14: Leading edge noise
Abstract
14.1 The compressible flow blade response function
14.2 The acoustic far field
14.3 An airfoil in a turbulent stream
14.4 Blade vortex interactions in compressible flow
15: Trailing edge and roughness noise
Abstract
15.1 The origin and scaling of trailing edge noise
15.2 Amiet's trailing edge noise theory
15.3 The method of Brooks, Pope, and Marcolini [8]
15.4 Roughness noise
Part 4: Rotating blades and duct acoustics
16: Open rotor noise
Abstract
16.1 Tone and broadband noise
16.2 Time domain prediction methods for tone noise
16.3 Frequency domain prediction methods for tone noise
16.4 Broadband noise from open rotors
16.5 Haystacking of broadband noise
16.6 Blade vortex interactions
17: Duct acoustics
Abstract
17.1 Introduction
17.2 The sound in a cylindrical duct
17.3 Duct liners
17.4 The Green's function for a source in a cylindrical duct
17.5 Sound power in ducts
17.6 Nonuniform mean flow
17.7 The radiation from duct inlets and exits
18: Fan noise
Abstract
18.1 Sources of sound in ducted fans
18.2 Duct mode amplitudes
18.3 The cascade blade response function
18.4 The rectilinear model of a rotor or stator in a cylindrical duct
18.5 Wake evolution in swirling flows
18.6 Fan tone noise
18.7 Broadband fan noise
Appendix A: Nomenclature
A.1 Symbol conventions, symbol modifiers, and Fourier transforms
A.2 Symbols used
Appendix B: Branch cuts
Appendix C: The cascade blade response function
Index
