PH3451 Fundamental Acoustics

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.

Prerequisite

PH3119, PH3991

Lecture Hours

Lab Hours

Course Learning Outcomes

Upon successful completion of this course, a student will:

Understand sound pressure oscillations in a fluid medium and derive the linear wave equation from first principles
Express simple solutions to the wave equation such as plane-, spherical-, and cylindrical-waves using exponential notation
Characterize the energy carried by sound waves and the relationship between intensity and geometrical spreading of the wavefront
Relate frequency, wavelength, and wavenumber via the speed of sound
Quantify sound levels in units of decibels
Use the principle of superposition and Fourier Synthesis to describe broadband sound
Calculate the reflection, transmission, and refraction of plane waves at the interface between two media
Understand the mechanism by which an acoustic source (e.g., a baffled piston) radiates sound energy into the medium
Understand how and why acoustic waves attenuate as they propagate
Identify acoustic standing wave patterns, resonant frequencies, and normal modes in enclosures
Use microphones to measure sound pressure for experiments and condition the signal with filters and amplifiers to optimize signal-to-noise ratio
Perform measurements of sound radiation patterns in an anechoic chamber and operate a lock-in amplifier.