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

Format:

Book

Author/Creator:

Glegg, Stewart.

Contributor:

Devenport, William.

Language:

English

Subjects (All):

Aeroacoustics.

Fluid dynamics.

Physical Description:

1 online resource (724 pages)

Edition:

2nd ed.

Place of Publication:

San Diego : Elsevier Science & Technology, 2023.

Summary:

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. Generated by AI.

Contents:

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

Notes:

Description based on publisher supplied metadata and other sources.

Part of the metadata in this record was created by AI, based on the text of the resource.

ISBN:

9780443218583

0443218587

OCLC:

1401059482