Engineering and the Environment, University of Southampton

Knowledge and understanding
Having successfully completed the module, you will be able to:

• Discuss the generation and propagation of sound in fluids.
• Explain the principle of the Lighthill Acoustic Analogy, and how this is related to sound generated by turbulent flows.
• Explain how scaling laws may be derived (for some simple examples), and to interpret these.
• Explain how mean flow and boundaries can affect sound generation and propagation
.
• Apply aeroacoustics theory to new problems).
• Understanding of some of the current state-of-the-art research in aeroacoustics.

Cognitive (thinking) skills
Having successfully completed the module, you will be able to:

• Recognize “aeroacoustics” problems.
• Analyse aeroacoustics problems and select appropriate methods for solution of the problems.
• Assess whether the complexity of a problem in aeroacoustics may be reduced, e.g. by the use of scaling laws.
• Improved ability to read and interpret scientific textbooks and papers related to aeroacoustics.

Practical, subject specific skills
Having successfully completed the module, you will be able to:

• Recognize and define terms specific to aeroacoustics.
• Use relevant mathematical methods to solve problems in aeroacoustics.
• Link theory related to fluid dynamics and acoustics.
• Synthesise theory from different fields of study (eg. fluid dynamics, acoustics, mathematical methods).
• Model complex noise generation problems.
• Appreciate the difficulties associated with modelling aeroacoustic problems.

Key transferable skills

• Write computer programs and reports.
• Apply critical analysis and evaluation skills.
• Ability to read, understand and interpret scientific papers.
• Synthesise information from a range of sources.
• Communicate clearly in written reports.

The specific aim of this module is to introduce some of the fundamental theory of aeroacoustics. Also, a more general aim (as stated by the University Learning and Teaching Strategy) is the pursuit of scholarship, leading to highly employable graduates who are able to be responsible for their own learning.

• To define “aeroacoustics”.
• To review (relevant) theory of fluid dynamics and acoustics.
• To explain how aeroacoustics is linked to fluid dynamics.
• To introduce some of the fundamental theory of aeroacoustics, by utilizing relevant theory of fluid dynamics and acoustics.
• To describe some applications of aeroacoustics.
• To explain how to apply relevant mathematical methods to solve problems in aeroacoustics.
• To provide the basis for students to be able to conduct research in aeroacoustics.

• What is aeroacoustics?
• Review of unsteady fluid flow.
• Derivation of the acoustic wave equation and its solutions (Green’s functions).
• The effect of flow on sound sources.
• Lighthill’s Acoustic Analogy.
• Application of Lighthill’s Acoustic Analogy to turbulent flows; scaling laws.
• The effect of boundaries.

Up to three lectures per week. Two lectures per week will be used to present the theory and worked examples. (Typically, the lecture notes will be available in electronic format.) The remaining lecture will be used for a problems class.

Private study: students are expected to consult relevant textbooks and research papers, in order to further research the information and theory explained during lectures.

Problems sheets will be provided which contain exercises similar to the worked examples presented during the lectures. These will be backed up (as required) by problems classes. Also, solutions to the exercises will be provided.

At the start of the module, these problems classes also will be used to assist with problems related to the necessary mathematical methods, fluid dynamics and acoustics theory which is used on this course. This extra support should assist students who are less familiar with some of this theory.

Revision lectures at the end of the course should provide additional time to discuss typical examples of exam questions.

A coursework assignment will require you to apply some of the aeroacoustics theory presented in the lectures to a practical problem. This is likely to require some simple computer programming, and further reading, in addition to using the material provided during the lectures.

Core text

Sound and Sources of Sound 1st Edition, 1983, A P Dowling
J E Ffowcs William, Ellis Horwood Ltd