Sound Propagation (eBook)

Yang-Hann Kim is a Professor of Mechanical Engineering at Korea Advanced Institute of Science and Engineering (KAIST), where he is also Director of the Center for Noise and Vibration Control (NOVIC). He has been teaching acoustics at undergraduate and graduate levels for more than 20 years. Kim's research interests include sound visualization, active noise/vibration control, sound focusing, structural acoustics and duct acoustics. He has won numerous awards, including the Excellence Award in Technology Teaching from Ministry of Industrial Development, Second Place Award at the Gallery of Acoustics during the 132nd meeting of the ASA, and other awards at KAIST and from Korean acoustical societies. He is an active with various journals and societies, having served on the editorial board of the Journal of Sound and Vibration for 11 years and continuing to serve on the Editorial Board as the Handling editor of the Journal of Mechanical Systems and Signal Processing. Kim holds a B.S in Naval Architecture and Marine Engineering from Seoul National University and a PhD in Mechanical Engineering from MIT.

Preface.

Acknowledgments.

1 Vibration and Waves.

1.1 Introduction/Study Objectives.

1.2 From String Vibration to Wave.

1.3 One-dimensional Wave Equation.

1.4 Specific Impedance (Reflection and Transmission).

1.5 The Governing Equation of a String.

1.6 Forced Response of a String: Driving Point Impedance.

1.7 Wave Energy Propagation along a String.

1.8 Chapter Summary.

1.9 Essentials of Vibration and Waves.

1.9.1 Single- and Two-degree of Freedom Vibration Systems.

1.9.2 Fourier Series and Fourier Integral.

1.9.3 Wave Phenomena of Bar, Beam, Membrane, and Plate.

Exercises.

2 Acoustic Wave Equation and Its Basic PhysicalMeasures.

2.1 Introduction/Study Objectives.

2.2 One-dimensional Acoustic Wave Equation.

2.3 Acoustic Intensity and Energy.

2.4 The Units of Sound.

2.5 Analysis Methods of Linear Acoustic Wave Equation.

2.6 Solutions of the Wave Equation.

2.7 Chapter Summary.

2.8 Essentials of Wave Equations and Basic PhysicalMeasures.

2.8.1 Three-dimensional Acoustic Wave Equation.

2.8.2 Velocity Potential Function.

2.8.3 Complex Intensity.

2.8.4 Singular Sources.

Exercises.

3 Waves on a Flat Surface of Discontinuity.

3.1 Introduction/Study Objectives.

3.2 Normal Incidence on a Flat Surface of Discontinuity.

3.3 The Mass Law (Reflection and Transmission due to a LimpWall).

3.4 Transmission Loss at a Partition.

3.5 Oblique Incidence (Snell's Law).

3.6 Transmission and Reflection of an Infinite Plate.

3.7 The Reflection and Transmission of a Finite Structure.

3.8 Chapter Summary.

3.9 Essentials of Sound Waves on a Flat Surface ofDiscontinuity.

3.9.1 Locally Reacting Surface.

3.9.2 Transmission Loss by a Partition.

3.9.3 Transmission and Reflection in Layers.

3.9.4 Snell's Law When the Incidence Angle is Larger than theCritical Angle.

3.9.5 Transmission Coefficient of a Finite Plate.

Exercises.

4 Radiation, Scattering, and Diffraction.

4.1 Introduction/Study Objectives.

4.2 Radiation of a Breathing Sphere and a Trembling Sphere.

4.3 Radiation from a Baffled Piston.

4.4 Radiation from a Finite Vibrating Plate.

4.5 Diffraction and Scattering.

4.6 Chapter Summary.

4.7 Essentials of Radiation, Scattering, and Diffraction.

4.7.1 Definitions of Physical Quantities RepresentingDirectivity.

4.7.2 The Radiated Sound Field from an Infinitely BaffledCircular Piston.

4.7.3 Sound Field at an Arbitrary Position Radiated by anInfinitely Baffled Circular Piston.

4.7.4 Understanding Radiation, Scattering, and Diffraction Usingthe Kirchhoff-Helmholtz Integral Equation.

4.7.5 Scattered Sound Field Using the Rayleigh IntegralEquation.

4.7.6 Theoretical Approach to Diffraction Phenomenon.

Exercises.

5 Acoustics in a Closed Space.

5.1 Introduction/Study Objectives.

5.2 Acoustic Characteristics of a Closed Space.

5.3 Theory for Acoustically Large Space (Sabine's theory).

5.4 Direct and Reverberant Field.

5.5 Analysis Methods for a Closed Space.

5.6 Characteristics of Sound in a Small Space.

5.7 Duct Acoustics.

5.8 Chapter Summary.

5.9 Essentials of Acoustics in a Closed Space.

5.9.1 Methods for Measuring Absorption Coefficient.

5.9.2 Various Reverberation Time Prediction Formulae.

5.9.3 Sound Pressure Distribution in Closed 3D Space Using ModeFunction.

5.9.4 Analytic Solution of 1D Cavity Interior Field with AnyBoundary Condition.

5.9.5 Helmholtz Resonator Array Panels.

Exercises.

Index.

"These measures are all illustrated by one-dimensional examples, which provide mathematically simplest but clear enough physical insights.... The bulk of the book is concerned with introducing fundamental concepts, but the appendices cover some additional topics to extend the learning." (Zentralblatt MATH, 2011)