Aka Ljud och vibrationer, introduktionskurs
General Course Information
|Course code||VTA121, course description|
|Course Administration||Patrik Höstmad|
|Lecturers||Patrik Höstmad, Pontus Thorsson|
|Lecture hall||Lecture room at TA as well as SB-L408|
|Exam||Project work reports (graded), laboratory work report (approved), written exam (graded)|
Written exam 170314 and final grades incl. project work:
The ‘final grade’ is the grade that will be reported.
Review of the exam: March 30, 2015, 10:00-10:30 in my office at the Division of Applied Acoustics.
Suggestion of answers to the exam of today is posted in the Exam-section below. The review of the exam is in my office at the Division of Applied Acoustics, March 30, 2017, 10:00-10:30.
The deadline for project work 4 is postponed to the 7th of March.
The lecture Thursday March 2, 09:00-11:45 is moved to the lecture hall SB-L408.
Posted 170223 2017-02-23
On Monday Feb 27 after 15:00, and after ev. a general presentation by Julia, we offer a visit to the anechoic camber and transmission suit at the department of Applied Acoustics for all students participating in the ISV-course. We show the rooms and play som demo:s.
Deadline for the third project work is postponed to Wednesday (22/2) evening (18.00).
Movies have been uploaded to the “LECTURES” section, see “Lecture 8 Movies of Lecture 8”. The five movies are in a zipped file.
I have had a discussion with Julia and here some feedback and information on what we came up with:
- I will put video examples on the course page.
- I will try to give more examples of applications at the lectures.
- The corrections of the reports have been delayed since Julia’s computer crashed. Should be solved soon.
- As suggested in the notes. You could e-mail your problems to Julia, preferably before lunchtime the day before the supervision time, and if there are several questions of the same type, she will give info to all at the start of the supervision time.
- Generally, do not hesitate to ask ask ask about the project work. The pedagogical idea is that there should be a lot of discussion about the tasks.
- And speaking about discussions: You could also ask other students for hints and information. Julia will work more with addressing your questions to other students that have solved the task when possible, so she can spend more time for questions that nobody else can answer.
updated deadlines for Project work 2 and 3.
updated version of the isv.m file .
The page is about to be updated for year 2016/2017.
The first lecture is Monday Jan 16, 2016, at 13:15 in the Teaching Laboratory at Applied Acoustics (Avd. fr teknisk akustik). How to find Applied Acoustics: Map
The laboratory work is held starting Friday Study Week 1 and during Study Week 2. A booking list will be available during study week 1.
Download Moving Acoustics (software for Windows). It is a collection of animations and sounds, which demonstrate the physical processes behind acoustics, like wave propagation, sound sources, Snells law etc.
- Lecture 1 Introduction
- Lecture 2-3 Sound waves and acoustic sources
- Lecture 4 Physical phenomena influencing sound propagation
- Lecture 5 Sound propagation outdoors
- Lecture 6 Waves and vibrations on solids
- Lecture 7 Sound radiation from structures
- Lecture 8 Vehicle acoustics and community noise
- Lecture 8 Movies of Lecture 8
- Lecture 8 Silencers
- Lecture 9 Vibration isolation (updated 24 Feb 2016)
- Lecture 10–11 Sound fields in cavities
- Lecture 12 Sound insulation part 1
- Lecture 13 Sound insulation part 2
- Lecture 14 Flanking transmission, Practical Building Acoustics
- Lecture 14 Building Acoustics (Pontus Thorsson’s presentation)
- Lecture 15 Absorbers
- Summary related to learning outcomes
- Summary – the flow chart
- Animations A collection with some of the Matlab-animations presented during the lectures.
The project work reports are made in groups of two students and will be graded. Send the written report by e-mail in pdf-format to Julia Winroth. Matlab or Octave is to be used for the analysis in the project work.
Deadline for handing in the written report is one week after your scheduled laboratory time.
- Lab. work description . Please, read it carefully before the lab.
- isv.m – The MATLAB function used during the lab. work measurements.
- R_A weighting function – MATLAB function for the A-weighting.
- Archive.zip Test measurement files to play around with.
- (PHO120 – Sound Waves)
- (PHO121 – Speech Analysis)
- (Another way to measure reverberation time by Clive Greated)
Introduction: Jan 26, 2017.
Deadline for handing in the written report: Feb 13, 2017.
- Project work – Part 2
- tailpipe_measurements.zip – Measured pressure and transfer functions in a zipped mat-file.
- ISV_pw2_leastsquare.m – MATLAB function for solving the least-square problem.
- idling_sounds.zip – wav-files with sound recorded in the passenger compartment and the two exterior receiving positions to give you an idea of what was recorded. It is hard to exactly recreate the sound that was present as your loudspeakers and gain will affect the sound — however, the sound gives at least an indication of reality.
- Tutorial explaining MATLAB’s transpose operator – You only need this if you want to solve the least-square problem without the function we provided.
- Slides from the introduction of project 2.
Introduction: Feb 9, 2017.
Deadline for handing in the written report: Feb 22, 2017.
- Project work – Part 3 incl. excerpts from the Nordic Prediction Method.
- NPM_Functions.zip – Matlab functions for the Nordic Prediction Method.
- Introduction slides from the lecture.
If you want to know more about community noise, prediction models, sound propagation outdoors etc:
- The web resource “Ljudlandskap” contains a lot of information (mainly in swedish), note the different levels “Nyfikna, Anvandare, Specialister”:
- LjudlandskapThe Nordic prediction method for road traffic noise – a journal paper by H. Bendtsen (1999).
- A modified Nordic prediction model of road traffic noise in a Taiwanese city with significant motorcycle traffic (journal article by Ta-Yuan Chang et. al. (2012))
Introduction: Feb 23, 2017.
Deadline for handing in the written report: Mar 7, 2017.
- Project work – Part 4.
- R_wall.zip – Matlab functions for the single and double wall task.
- Introduction slides from the lecture.
- Paper on transmission loss by Wentzel & Saha.
The laboratory work is included in project work part 1.
Basic knowledge and understanding will be evaluated in the written exam.
- Exam 130316 and Suggestions of answers
- Exam 140315 and Suggestions of answers
- Exam 150321 and Suggestions of answers
- Exam 160319 and Suggestions of answers
- Exam 170314 and Suggestions of answers
Matlab and Octave
It is recommended to use either Matlab or Octave for your project work.
Chalmers students can obtain Matlab here.
The free software Octave is a good alternative to Matlab. The language and all basic functions which will be used in the course are identical in Matlab and Octave.
- Some nice-to-know-things for the use of MATLAB (or Octave) in ISV. This is a summary of the short Matlab introduction which was given in the lectures.
- Matlab introduction for ISV. This presents an introduction into how to do some common tasks related to acoustics in MATLAB. It also shows some common pitfalls and how to avoid them. Also available as an m-file for possible code reuse.
- General Matlab tutorial (optional reading) by Pekalska and van der Glas, Delft Univ. of Techn. Possibly relevant sections are marked.
- General Matlab tutorial (optional reading) by Griffiths, Univ. of Dundee. Possibly relevant sections are marked.
- Even more Matlab tutorials can be found at Mathworks’ website.
Here are some additional material for the interested reader.
- The use of complex notation. Some examples to refresh your memory.
- The use of logarithms. Some examples to refresh your memory.
- Introduction to sound and vibration by Wolfgang Kropp and Krister Larsson. In this text you will find brief description of the importance of acoustics as discipline, it main applications and its relation to our daily life at work and at home.
- The three-dimensional wave equation by Pontus Thorsson. A full derivation of the three-dimensional wave equation in solids and fluids.
Suggestions of literature
Here are some suggestions of literature for the interested and for future use. Notice that non of these textbooks are official course literature (the lecture notes posted on this home page are the official course literature). The comments after each book are my very own subjective statements. /Patrik
Building Acoustics / Tor Erik Vigran (357 pages)
A very good book about building acoustics that is up-to-date (most other books are not). The book gives a deep understanding of the underlaying physics and state-of- the-art formulas for engineers. Is also available on Norwegian (see below).
Engineering Noise Control – theory and practice / D.A. Bies (700 pages)
A very extensice book covering a wide range of topics. It was perviously course literature in the course “Engineering Acoustics” a couple of years ago. It was sometimes critisised by Students for being wordy.
Noise and Vibration Control / Leo L. Beranek (650 pages)
A very extensice book covering a wide range of topics. As an example, it contains an extensive and very good chapter on mufflers including effects of flow. However, it is not as up to date as the books of Bies or Vigran.
Bygningsakustikk – et grunnlag av Tor Erik Vigran (300 sidor)
En mycket bra bok om byggnadsakustik som är up-to-date (till skillnad från de flesta andra). Boken ger en djupare fysikalsisk förståelse och dags-aktuella formler för ingenjörer. Den var tidigare kurslitteratur i den numera avvecklade kursen Akustik, hus. Finns bara på norska, men det är inga problem om man kan svenska.
Ljud och Vibrationer av Boden, Carlsson, Glav, Wallin och Åbom (400 sidor)
En bok som täcker både luftljud och strukturljud med lutning åt akustik för maskininriktningen. Boken täcker mycket vilket leder till att de fysikaliska beskrivningarna ibland är korta – den djupare förståelsen kan vara svårt att få.
Byggnadsakustik – en praktisk handbok av Leif Åkerlöf (300 sidor)
En handbok för den som redan har förstått – boken ger ingen hjälp till att lära sig något nytt.