## PH 3451: Fundamental Acoustics

**PH 3451: Fundamental Acoustics**. Instructor: Prof. Bruce Denardo, Department of Physics, NPS (Naval Postgraduate School). Development of, and solutions to, the acoustic wave equation in fluids; propagation of plane, spherical and cylindrical waves in fluids; sound pressure level, intensity, and specific acoustic impedance; normal and oblique incidence reflection and transmission from plane boundaries; transmission through a layer; image theory and surface interference; sound absorption and dispersion for classical and relaxing fluids; acoustic behavior of sources and arrays, acoustical reciprocity, continuous line source, plane circular piston, radiation impedance, and the steered line array; transducer properties, sensitivities, and calibration. Laboratory experiments include longitudinal waves in an air-filled tube, surface interference, properties of underwater transducers, three-element array, speed of sound in water, and absorption in gases. Textbook: Kinsler, Frey, Coppens, and Sanders, Fundamentals of Acoustics, 4th Edition.

Lecture 01 - Introduction, Acoustic Wave Equation: Fluid Description |

Lecture 02 - Acoustic Wave Equation: Equation of State, Equation of Continuity |

Lecture 03 - Linear Wave Equation: Speed of Sound |

Lecture 04 - Problem Set: Acoustic Wave Equation |

Lecture 05 - Plane Waves, Energy Density |

Lecture 06 - Energy Density, Acoustic Intensity and Wave Impedance |

Lecture 07 - Spherical Waves |

Lecture 08 - Problem Set: Plane Waves, Energy Density, Acoustic Intensity, Spherical Waves |

Lecture 09 - Decibel Scales, Transducers |

Lecture 10 - Reflection and Transmission |

Lecture 11 - Problem Set: Decibel Scales, Transducers |

Lecture 12 - Reflection and Transmission: Normal Incidence |

Lecture 13 - Reflection and Transmission: Oblique Incidence |

Lecture 14 - Reflection and Transmission: Method of Images, Far Field of a Two-Point Source |

Lecture 15 - Problem Set: Reflection and Transmission |

Lecture 16 - Radiation from a Pulsating Sphere, Acoustic Reciprocity |

Lecture 17 - Radiation: Acoustic Reciprocity, Uniform Line Source |

Lecture 18 - Problem Set: Radiation |

Lecture 19 - Radiation: Helmholtz Resonators |

Lecture 20 - Radiation: Baffled Plane Circular Piston |

Lecture 21 - Far Field Radiation Pattern of a Baffled Piston, Radiation Impedance |

Lecture 22 - Radiation Impedance and Examples, Properties of Sources |

Lecture 23 - Problem Set: Baffled Piston, Radiation Impedance |

Lecture 24 - Radiation: Directivity |

Lecture 25 - Attenuation of Sound: Thermodynamics Example, Viscosity |

Lecture 26 - Problem Set: Directivity, Attenuation of Sound |

Lecture 27 - Attenuation of Sound: Complex Speed of Sound, Thermal Losses |

Lecture 28 - Attenuation of Sound: Classical Absorption Coefficient, Molecular Thermal Relaxation |

Lecture 29 - Problem Set: Attenuation of Sound |

Lecture 30 - Attenuation of Sound: Acoustic Calculation |

Lecture 31 - Attenuation of Sound: Absorption of Sound in Air and Water |

Lecture 32 - Problem Set: Attenuation of Sound |

Lecture 33 - Sound in Pipes: Resonance in Pipes |

Lecture 34 - Sound in Pipes: Power of Radiation from Open Ends, Wave Pattern inside a Pipe |

Lecture 35 - Absorption of Sound in Pipes |

Lecture 36 - Sound in Pipes: Driver-Pipe System |

Lecture 37 - Acoustics in Cavities |

Lecture 38 - Problem Set: Sound in Pipes |