Course syllabus
Akustik
Acoustics
VTAF05, 7,5 credits, G2 (First Cycle)
Valid for: 2014/15
Decided by: Education Board D
Date of Decision: 2014-04-03
General Information
Elective for: V4-hb, V5-ko
Language of instruction: The course will be given in English on demand
Aim
The purpose with the course is to give knowledge about sound
propagation in different media.
Learning outcomes
Knowledge and understanding
For a passing grade the student must
- Be able to describe the physical foundations of waves in solid
materials and describe wave propagation in infinite media
and structural elements such as rods, beam and plates.
- Be able to interpret fundamental concepts such as acoustic
effect, intensity and wave impedance.
- Be able to describe different mechanisms for damping and
methods for experimental measurement of damping and have knowledge
about how to change the damping properties of a structure.
- Be able to understand and use expressions for point impedance
for infinite beams and plates.
- Be able to describe the causes for sound reflection and
transmission at blocking elements and understand what happens at a
periodic occurance of blocking elements.
- Be able to describe sound radiation from structures.
- Understand how sound is propagating in ventilation systems and
explain how to attend to ventilation related noise problems.
- Be able to predict and measure noise from wind turbines
- Be able to predict and measure sound reduction index in walls
and structures
- Be able to predict and measure simple sound invironments
Competences and skills
For a passing grade the student must
- Be able to calculate the eigenfrequencies, eigenmodes and mode
density in finite systems with simple geometries and boundary
conditions.
- Be able to analyse a given construction with regards to sound
reflection and transmission.
- For a given structural element, be able to design a
discontinuity in order to achieve a wanted reflection.
- Be able to calculate the sound radiation from a point-, line-
and plane source.
- Easily use concept introduced in the course, such as impedance,
loss factor, radiation factor.
- Be able to present the solution of a given acoustic problem in
a written technical report.
Contents
Different wave types and their respective properties.
Longitudinal, transversal and bending waves. Wave propagation in
beams and plates. Wave propagation, transmission and reflection in
and between different meda. Damping mechanisms and the mathematical
description. Plates with damping layers. The concept of impedance.
Inimpedance in beams and plates. Transmission of structure bourne
sound. Periodical structures. Noise in ventilation systems.
Statistical Energy Analysis. Sound radiation from structures.
Elementary sound radiators. Acoustics in volumes.
The course contains a larger project task where several of these
aspects are included..
Laborations
The course contains three laborations á 4 hours where the content
varies depending on the focus of the course during the given year.
Example of laborations are:
- Introduction to sound propagation
- Impedance measurement
- Sound propagation in solid media
- Reverberation time and eigenmodes in room acoustics
- Sound transmission
- Step sound isolation
- Measurement of noise from wind turbines
(the lab facilities will be closed due to retrofitting during
autumn -14, and thus the laborations will take place at other
locations)
Project tasks
The course contain a project task that is aimed at a topic
according to the given foces of the course, such as:
- Modelling of oscillation in beams and plates
- Modelling of flanking and direct transmission
- Measurement and evaluation of noise from wind turbines
Examination details
Grading scale: TH
Assessment: Passed written exam, passed project task and passed laboration reports.
Admission
Required prior knowledge: FMAA05 Calculus in One Dimension and FMA430 Calculus in Several Variables and VTAF01 Sound in Building and Environment.
The number of participants is limited to: No
The course overlaps following course/s: VTA016, VTA060
Reading list
- Course literature is handed out by the department.
- Lecture notes and instructions for construction tasks and laborations.
Contact and other information
Course coordinator: Delphine Bard, delphine.bard@acoustics.lth.se
Teacher: Kristian Stålne, kristian.stalne@construction.lth.se
Course homepage: http://www.akustik.lth.se