CHAPTER V - MEMBRANES AND PLATES
17. The Equation of Motion
Forces on a Membrane. The Laplacian Operator.
Boundary Conditions and Coordinate Systems.
Reaction to a Concentrated Applied Force
18. The Rectangular Membrane
Combinations of Parallel Waves. Separating the Wave
Equation. The Normal Modes. The Allowed
Frequencies. The Degenerate Case. The
Characteristic Functions
19. The Circular Membrane
Wave Motion on an Infinite Membrane. Impermanence
of the Waves. Simple Harmonic Waves. Bessel
Functions. The Allowed Frequencies. The
Characteristic Functions. Relation between Parallel
and Circular Waves. The Kettledrum. The Allowed
Frequencies
20. Forced Motion. The Condenser Microphone
Neumann Functions. Unloaded Membrane, Any Force.
Localized Loading, Any Force. Uniform Loading,
Uniform Force. The Condenser Microphone. Electrical
Connections. Transient Response of Microphone
21. The Vibration of Plates
The Equation of Motion. Simple Harmonic Vibrations.
The Normal Modes. Forced Vibration
Problems
CHAPTER VI - PLANE WAVES OF SOUND
22. The Equation of Motion
Wave along a Tube. The Equation of Continuity.
Compressibility of the Gas. The Wave Equation.
Energy in a Plane Wave. Intensity. The Decibel Scale.
Intensity and Pressure Level. Sound Power. Frequency
Distribution of Sounds. The Vowel Sounds.
23. The Propagation of Sounds in Tubes
Analogous Circuit Elements. Constriction. Tank.
Examples. Characteristic Acoustic Resistance. Incident
and Reflected Waves. Specific Acoustic Impedance.
Standing Waves. Measurement of Acoustic
Impedance. Damped Waves. Closed Tube. Open
Tube. Small-diameter Open Tube. Reed Instruments.
Motion of the Reed. Pressure and Velocity at the Reed.
Even Harmonics. Other Wind Instruments. Tube as an
Analogous Transmission Line. Open Tube, Any
Diameter. Cavity Resonance. Transient Effect, Flutter
Echo.
24. Propagation of Sound in Horns
One-parameter Wave. An Approximate Wave
Equation. Possible Horn Shapes. The Conical Horn.
Transmission Coefficient. A Horn Loud-speaker. The
Exponential Horn. The Catenoidal Horn. Reflection
from the Open End, Resonance. Wood-wind
Instruments. Transient Effects
Problems
CHAPTER VII - THE RADIATION AND SCATTERING
OF SOUND
25. The Wave Equation
The Equation for the Pressure Wave. Curvilinear
Coordinates
26. Radiation from Cylinders
The General Solution. Uniform Radiation. Radiation
from a Vibrating Wire. Radiation from an Element of a
Cylinder. Long- and Short-wave Limits. Radiation from
a Cylindrical Source of General Type. Transmission
inside Cylinders. Wave Velocities and Characteristic
Impedances. Generation of Wave by Piston.
27. Radiation from Spheres
Uniform Radiation. The Simple Source. Spherical
Waves of General Form. Legendre Functions. Bessel
Functions for Spherical Coordinates. The Dipole
Source. Radiation from a General Spherical Source.
Radiation from a Point Source on a Sphere. Radiation
from a Piston Set in a Sphere
28. Radiation from a Piston in a Plane Wall
Calculation of the Pressure Wave. Distribution of
Intensity. Effect of Piston Flexure on Directionality.
Radiation Impedance, Rigid Piston. Distribution of
Pressure over the Piston. Nonuniform Motion of the
Piston. Radiation out of a Circular Tube. Transmission
Coefficient for a Dynamic Speaker. Design Problems
for Dynamic Speakers. Behavior of the Loud-speaker.
Transient Radiation from a Piston.
29. The Scattering of Sound
Scattering from a Cylinder. Short Wavelength Limit.
Total Scattered Power. The Force on the Cylinder.
Scattering from a Sphere. The Force on the Sphere.
Design of a Condenser Microphone. Behavior of the
Microphone.
30. The Absorption of Sound at a Surface
Surface Impedance. Unsupported Panel. Supported
Panel. Porous Material. Equivalent Circuits for Thin
Structures. Formulas for Thick Panels. Reflection of
Plane Wave from Absorbing Wall.
31. Sound Transmission through Ducts
Boundary Conditions. Approximate Solutions. Principal
Wave. Transient Waves. The Exact Solution. An
Example
Problems