ISVR2042 Acoustics II
This module builds on the knowledge and understanding of sound fields and their generation and propagation that was built up in ISVR1032 Acoustics I. Those fundamental concepts are explored in greater depth to allow them to be applied to a wide variety of practically important systems, such as ducts, rooms and barriers.
Aims and Objectives
• To develop a competence in the theoretical analysis of simple acoustical systems • To convey the fundamental physical principle that under pin the behaviour of sound in free field and bounded environments and the behaviour and characteristics of simple acoustic sources. • To allow the student to gain laboratory experience in analysing and interpreting the acoustic measurements in complex scenarios. To present their results formally, together with a critical assessment of the experimental methods and the limitations of their data.
Disciplinary Specific Learning Outcomes
Having successfully completed this module you will be able to:
- Discuss the continuity and momentum equations of fluid dynamics and use them to derive the acoustic wave equation in three dimensions.
- Explain the relationship between the wave equation and the Helmholtz equation, verify the equivalence of the two approaches when solving acoustical problems, and choose which one is appropriate in a given situation.
- Define and calculate sound energy and sound intensity.
- Account, qualitatively, for the mechanisms of energy loss when sound is absorbed and distinguish between locally reacting and non-locally reacting boundaries.
- Calculate the sound-field of monopole and dipole sources and source distributions, illustrate them by means of computer programs, and recognise their relationship to practical sources.
- Use the Helmholtz equation to obtain the modes of an acoustical space and explain how they can be used to obtain solutions to source radiation problems in that space.
- Calculate the transmitted and reflected waves when plane waves are obliquely incident on a plane interface between two fluids.
- Explain the basic measurements made when assessing room acoustics and relate them to the acoustical theory previously developed and the description of absorption.
1. Revision of basic principles of 1D sound propagation from Part I. 2. Conservation equations of compressible fluid dynamics for 3D sound fields. 3. The Helmholtz equation and the Wave equation in three dimensions. 4. Sound energy, sound power and sound intensity. 5. Sources of sound: monopoles, dipoles, vibrating surfaces. 6. Acoustic modes in ducts, enclosure and other systems. 7. Transmission and reflection of plane waves obliquely incident on a plane boundary. Labs: 1. Impedance tube measurement. 2. Sound power measurement. 3. Vibroacoustics.
Learning and Teaching
Teaching and learning methods
This is a one-semester course, two lectures and one tutorial per week with three laboratory sessions. Lecture notes and tutorial sheets are provided and one-to-one assistance and verbal feedback is facilitated through twelve tutorial classes. Past exam papers are supplied to aid personal study, feedback and revision. Blackboard is used to allow the lectures and additional material to be disseminated (including solutions to past exam papers). The students have to write-up one laboratory report and one assignment report. Students are encouraged to read supporting texts and a booklist is provided.
|Total study time||150|
Resources & Reading list
Fahy F. J. (2000). Foundations of engineering acoustics.
|Exam (120 minutes)||85%|
|Exam (120 minutes)||100%|
Repeat type: Internal & External
The practical sessions will be held in teaching laboratory 13/4061 using a multiplicity of existing bespoke rigs and standard vibration measuring equipment. About 10 students can be accommodated per laboratory session. Pre-requisite: ISVR1032 - Acoustics 1.
To study this module, you will need to have studied the following module(s):