Muutke küpsiste eelistusi

Physics of Nonlinear Waves [Pehme köide]

This is an introductory book about nonlinear waves. It focuses on two properties that various different wave phenomena have in common, the "nonlinearity" and "dispersion", and explains them in a style that is easy to understand for first-time students.

Both of these properties have important effects on wave phenomena. Nonlinearity, for example, makes the wave lean forward and leads to wave breaking, or enables waves with different wavenumber and frequency to interact with each other and exchange their energies.

Dispersion, for example, sorts irregular waves containing various wavelengths into gentler wavetrains with almost uniform wavelengths as they propagate, or cause a difference between the propagation speeds of the wave waveform and the wave energy.

Many phenomena are introduced and explained using water waves as an example, but this is just a tool to make it easier to draw physical images. Most of the phenomena introduced in this book are common to all nonlinear and dispersive waves.

This book focuses on understanding the physical aspects of wave phenomena, and requires very little mathematical knowledge. The necessary minimum knowledges about Fourier analysis, perturbation method, dimensional analysis, the governing equations of water waves, etc. are provided in the text and appendices, so even second- or third-year undergraduate students will be able to fully understand the contents of the book and enjoy the fan of nonlinear wave phenomena without relying on other books.

Preface xiii
Acknowledgments xv
1 The Simplest Nonlinear Wave Equation 1(20)
1.1 The Simplest Wave Equation
1(1)
1.2 From Conservation Law to Wave Equation
2(11)
1.2.1 Conservation Law
2(3)
1.2.2 From Conservation Law to Wave Equation
5(1)
1.2.3 Simple Model of Traffic Flow
5(8)
1.3 Method of Characteristics
1.4 Intersection of Characteristics and Occurrence of Multivaluedness
13(2)
1.5 Shock Fitting
15(5)
1.6 References
20(1)
2 Burgers Equation: Effect of Diffusion 21(14)
2.1 Burgers Equation
21(2)
2.2 Diffusion Effect
23(2)
2.3 Hopf-Cole Transformation: Close Relation to Diffusion Equation
25(1)
2.4 Typical Solutions of the Burgers Equation
26(8)
2.4.1 Uniform Solution
26(1)
2.4.2 Shock Wave Solution
27(3)
2.4.3 Coalescence of Shock Waves
30(3)
2.4.4 Bore
33(1)
2.5 References
34(1)
3 Basics of Linear Water Waves 35(30)
3.1 Dispersion Relation
35(6)
3.2 Linear Sinusoidal Wave Solution of Water Wave
41(12)
3.2.1 Basic Equations of Water Wave
41(1)
3.2.2 Sinusoidal Wave Solution and Linear Dispersion Relation
42(3)
3.2.3 Deep Water (or Short Wave) Limit
45(1)
3.2.4 Shallow Water (or Long Wave) Limit
46(1)
3.2.5 Refraction
46(3)
3.2.6 Motion of Water Particle
49(2)
3.2.7 Dispersion Relation by Dimensional Analysis
51(2)
3.3 Wave Energy and its Propagation Velocity
53(5)
3.3.1 Kinetic Energy and Potential Energy
53(2)
3.3.2 Energetic Consideration on the Dispersivity of Water Waves
55(1)
3.3.3 Energy Flux and Velocity of Energy Propagation
56(2)
3.4 Extension of Linear Solution to Nonlinear Solution
58(5)
3.4.1 Criteria for Validity of Linear Approximation
58(2)
3.4.2 Stokes Wave: Nonlinear Steady Traveling Wavetrains
60(3)
3.5 References
63(2)
4 Perturbation Method and Multiple Scale Analysis 65(14)
4.1 Necessity of Approximate Solution Method
65(1)
4.2 Perturbation Method
66(3)
4.2.1 Approximate Value of Root of Quadratic Equation
66(2)
4.2.2 Approximate Solution of Differential Equation
68(1)
4.3 Application to Nonlinear Pendulum
69(3)
4.3.1 Breakdown of Regular Perturbation Method
69(2)
4.3.2 Forced Oscillation and Resonance
71(1)
4.4 Multiple Scale Analysis
72(6)
4.4.1 Multiple Time Scale
72(1)
4.4.2 Application of Multiple Time Scale to Nonlinear Pendulum
73(5)
4.5 References
78(1)
5 KdV Equation: Effect of Dispersion 79(26)
5.1 KdV Equation and its Intuitive Derivation
79(3)
5.2 Solitary Wave Solution: Balance Between Nonlinearity and Dispersion
82(3)
5.3 Soliton: Solitary Wave with Particle Nature
85(10)
5.3.1 Discovery of Soliton
85(2)
5.3.2 Inverse Scattering Method: Exact Solution of KdV Equation
87(4)
5.3.3 Soliton Interaction
91(2)
5.3.4 Application of Soliton Theory to Water Waves
93(2)
5.4 Relatives of KdV Equation
95(3)
5.5 Whitham Equation and Wave Breaking
98(3)
5.6 References
101(4)
6 Modulation and Self-Interaction of a Wavetrain 105(36)
6.1 Modulated or Quasi-Monochromatic Wavetrain
105(1)
6.2 Group Velocity
106(11)
6.2.1 Group Velocity as Propagation Velocity of Modulation
106(3)
6.2.2 Group Velocity as Propagation Velocity of Energy
109(3)
6.2.3 Evidences of Energy Propagation at Group Velocity
112(5)
6.3 Nonlinear Schrodinger Equation: Equation Governing Modulation
117(14)
6.3.1 Contribution from Dispersion: Linear Schrodinger Equation
118(3)
6.3.2 Contribution from Nonlinearity: Mode Generation and Resonance
121(2)
6.3.3 Nonlinear Schrodinger Equation
123(5)
6.3.4 Envelope Soliton Solution
128(3)
6.4 Modulational Instability
131(8)
6.4.1 Stokes Waves and its Stability
132(1)
6.4.2 Stability Analysis Based on NLS Equation
133(2)
6.4.3 Intuitive Understanding of Modulational Instability
135(2)
6.4.4 Modulational Instability and Freak Wave
137(2)
6.5 References
139(2)
7 Resonant Interaction Between Waves 141(20)
7.1 Three-Wave Interaction
141(5)
7.1.1 Bound Wave Component
141(2)
7.1.2 Three-Wave Resonant Interaction
143(3)
7.2 Three-Wave Interaction Equation
146(4)
7.2.1 Derivation of Three-Wave Interaction Equation
146(2)
7.2.2 Manley-Rowe Relations
148(2)
7.3 Wave Generation and Excitation by Three-Wave Resonance
150(4)
7.3.1 Generation of the Third Wave by Two Waves
150(1)
7.3.2 Excitation of Two Waves by One Wave
151(3)
7.4 Special Types of Three-Wave Resonance
154(3)
7.4.1 Long-Wave Short-Wave Resonance
154(1)
7.4.2 Harmonic Resonance
155(2)
7.5 Four-Wave Resonant Interaction
157(2)
7.6 References
159(2)
8 Wave Turbulence: Interaction of Innumerable Waves 161(20)
8.1 Energy Spectrum
161(2)
8.2 Statistics About Wave Height
163(5)
8.2.1 Definition of Individual Waves and Representative Wave Height
163(2)
8.2.2 Probability Distribution of Wave Height
165(3)
8.3 Evolution Equation of Energy Spectrum
168(2)
8.4 Power Law Appearing in Energy Spectrum
170(8)
8.4.1 Kolmogorov Spectrum of Turbulence
170(4)
8.4.2 Power-Law Spectrum of Ocean Waves
174(4)
8.5 References
178(3)
A Conservation Law in 3D 181(4)
A.1 Flux Density Vector
181(1)
A.2 Conservation Law in Integral Form
182(1)
A.3 Conservation Law of Differential Form
182(3)
B System of Simultaneous Wave Equations 185(10)
B.1 Hyperbolic Equation
185(2)
B.2 Mechanism of Temporal Evolution of Hyperbolic System
187(2)
B.3 Riemann Invariant
189(2)
B.4 Simple Wave
191(2)
B.5 References
193(2)
C Summary of Fourier Analysis 195(4)
C.1 Fourier Series
195(1)
C.2 Fourier Transform
196(1)
C.3 Solution of the Diffusion Equation
197(2)
D Derivation of Governing Equations for Water Waves 199(8)
D.1 Mass Conservation Law
199(1)
D.2 Equation of Motion
200(1)
D.3 Lagrangian Derivative
201(1)
D.4 Kelvin's Circulation Theorem
202(1)
D.5 Potential Flow and Bernoulli's Theorem
203(3)
D.6 References
206(1)
E Summary to Dimensional Analysis 207(10)
E.1 Dimension and SI system
207(1)
E.2 Physical Quantities with Independent Dimensions
208(1)
E.3 Conversion of Unit System
209(1)
E.4 Pi Theorem
210(3)
E.5 Drag on an Object by Dimensional Analysis
213(2)
E.6 References
215(2)
F Derivation of the KdV Equation for Water Waves 217(8)
E1 The Basic Equations
217(1)
E2 Derivation of Long Wave Equation
218(2)
E3 Derivation of the KdV Equation
220(3)
E4 References
223(2)
G FPU Recurrence and the KdV Equation 225(8)
G.1 Normal Mode of Oscillation
225(3)
G.2 FPU Recurrence
228(1)
G.3 Derivation of the KdV Equation for Nonlinear Lattice
229(2)
G.4 References
231(2)
Author's Biography 233(2)
Index 235