Physical Acoustics Course

Lesson 1 • Nature of Mechanical Waves

Introduces longitudinal and transverse waves as disturbances in elastic media. Connects particle motion to macroscopic wave behaviour.

Lesson 2 • Introduction to the Wave Equation

Derives the linear acoustic wave equation from first principles. Establishes the mathematical backbone for all propagation models in the course.

Lesson 3 • Simple Harmonic Motion

Analyses the oscillator as the elementary source of sound. Links spring-mass dynamics to acoustic radiation concepts introduced later.

Lesson 4 • Frequency, Wavelength, and Wave Speed

Defines the fundamental wave parameters and their interrelationships. Builds quantitative skills needed for all subsequent acoustic analysis.

Lesson 1 • Refraction and Diffraction

Covers bending of wave paths due to speed gradients and obstacles. Connects these phenomena to practical sonar and ultrasonic imaging scenarios.

Lesson 2 • Reflection and Transmission at Interfaces

Analyses wave behaviour at boundaries between dissimilar media. Introduces acoustic impedance as the key parameter governing energy partitioning.

Lesson 3 • Sound Speed in Fluids and Solids

Relates material elastic constants and density to wave speed. Provides the basis for material characterisation using acoustic measurements.

Lesson 4 • Wave Propagation in Anisotropic Solids

Extends propagation theory to materials with directional elastic properties. Prepares students for ultrasonic testing of composites and crystals.

Lesson 1 • Dipole and Multipole Sources

Extends source modelling to dipoles and higher-order multipoles. Explains directional radiation patterns relevant to vibrating structures.

Lesson 2 • Point Sources and Monopoles

Introduces the monopole as the simplest acoustic source model. Derives the spherical wave solution and near-field versus far-field behaviour.

Lesson 3 • Acoustic Power and Radiation Impedance

Defines radiated acoustic power and the loading effect of the medium on a source. Links radiation resistance to transducer efficiency.

Lesson 4 • Radiation from Vibrating Surfaces

Models sound radiation from extended planar and curved surfaces. Introduces radiation efficiency and its dependence on structural wave speed.

Lesson 1 • Helmholtz Resonators

Models the Helmholtz resonator as a lumped acoustic system. Connects resonator geometry to tuned frequency for noise control applications.

Lesson 2 • Resonance in Acoustic Cavities

Extends modal analysis to two- and three-dimensional enclosures. Applies cavity modes to room acoustics and resonator design.

Lesson 3 • Structural Vibration Modes

Analyses flexural and torsional modes of beams, plates, and shells. Bridges structural dynamics and acoustic radiation for noise prediction.

Lesson 4 • Standing Waves in One Dimension

Derives standing wave patterns in tubes and rods with various boundary conditions. Establishes the concept of modal resonance frequencies.

Lesson 1 • Microphones and Hydrophones

Describes condenser, electret, and MEMS microphones alongside underwater hydrophones. Addresses sensitivity, frequency response, and dynamic range.

Lesson 2 • Piezoelectric Transducer Principles

Explains the piezoelectric effect and its use in acoustic transmitters and receivers. Connects material constants to transducer sensitivity and bandwidth.

Lesson 3 • Ultrasonic Transducer Arrays

Introduces phased and linear arrays for beam steering and focusing. Provides the foundation for imaging and nondestructive evaluation systems.

Lesson 4 • Signal Conditioning and Data Acquisition

Covers amplification, filtering, and analog-to-digital conversion for acoustic signals. Ensures accurate capture of transient and continuous wave data.

Lesson 1 • Shock Wave Formation and Structure

Describes the formation of acoustic shocks and their internal structure. Applies shock theory to lithotripsy, sonic booms, and explosive sources.

Lesson 2 • Harmonic Generation and Waveform Distortion

Analyses the progressive steepening of waveforms and growth of harmonics. Connects harmonic amplitudes to propagation distance and source level.

Lesson 3 • Origins of Acoustic Nonlinearity

Identifies the physical sources of nonlinearity in fluids and solids. Introduces the nonlinearity parameter B/A as a material characterisation tool.

Lesson 4 • Acoustic Streaming and Radiation Pressure

Covers steady fluid flows and forces induced by acoustic wave fields. Links these effects to particle manipulation and ultrasonic cleaning.

Lesson 1 • Phased Array Ultrasonic Testing

Applies array beamforming to flexible, high-resolution inspection of complex geometries. Covers sector scanning, focusing, and total focusing method imaging.

Lesson 2 • Flaw Detection and Sizing

Covers techniques for locating and measuring defects using amplitude and time-of-flight data. Introduces sizing methods based on diffraction and amplitude drop.

Lesson 3 • Pulse-Echo and Through-Transmission Methods

Introduces the two primary ultrasonic inspection configurations and their signal interpretation. Establishes the basis for flaw detection and sizing.

Lesson 4 • Material Property Measurement

Uses acoustic velocity and attenuation measurements to characterise material microstructure and mechanical properties. Links acoustic data to material quality metrics.

Lesson 1 • Computational Acoustics Methods

Introduces numerical methods for solving complex acoustic problems beyond analytical reach. Evaluates finite element, boundary element, and finite difference approaches.

Lesson 2 • Thermoacoustics

Analyses the coupling between acoustic oscillations and heat transfer in resonators. Applies thermoacoustic principles to refrigeration and prime mover design.

Lesson 3 • Acoustic Metamaterials and Phononic Crystals

Examines engineered periodic structures that exhibit unusual acoustic properties. Covers band gaps, negative effective parameters, and cloaking concepts.

Lesson 4 • High-Intensity Focused Ultrasound

Examines the physical mechanisms of tissue heating and cavitation in focused ultrasound therapy. Connects beam focusing, nonlinearity, and bioeffects.