CODE  108711 

ACADEMIC YEAR  2023/2024 
CREDITS 

SCIENTIFIC DISCIPLINARY SECTOR  INGIND/11 
LANGUAGE  English 
TEACHING LOCATION 

SEMESTER  1° Semester 
TEACHING MATERIALS  AULAWEB 
OVERVIEW
Acoustics is a key aspect in the development of any engineering product. The subject spans from theoretical modelling, measurements, the human perception of sound and vibrations, to practical design solutions.
This course will provide the fundamentals of engineering acoustics, covering applications such as: how to assess and improve the acoustics of a room and how to design an effective duct silencer or a vibration isolation system for a machinery. The concepts covered in the course can be applied to ships, aeroplanes, cars, buildings etc and the type of knowledge you will have after the course matches specific requirements from the jobmarket.
AIMS AND CONTENT
LEARNING OUTCOMES
The overall aim of the course is to provide skills to support development of quiet and vibrationfree products and processes. The course participants are provided knowledge and skills to carry out a relevant analysis of the sound and vibration characteristics of a product and to define design measures to support in the development of silent and vibration free products. Also, the knowledge provided serves as a basis for further studies in the sound and vibration field.
AIMS AND LEARNING OUTCOMES
After completing the course, the student should be able to:
 Account for and explain key sound and vibration concepts and quantities.
 Account for environmental consequences of sound and vibration.
 Account for, evaluate and critically choose relevant mathematical models and methods to describe important sound and vibration quantities.
 Apply relevant mathematical models and methods to calculate important sound and vibration quantities.
 Measure sound emission properties of a product.
 Measure and assess the handarm vibration exposure of a handheld tool.
PREREQUISITES
Basic mathematics including complex numbers and differential equations.
Basic mechanics and solid mechanics.
TEACHING METHODS
 Combined on campus (and if needed in parallel via teams …) lectures and tutorials. Students prepare by looking at a short videoclip (1520 min). A total of ca 30 minutes for each lecture is envisaged. Short preparation feedback quizzes are given in the beginning of each lecture.
 Laboratory exercises/demonstrations – Attendance is strongly recommended.
 Intermediate short exams to promote continuous learning. Participants can pass the final exam by successfully participating in the short exams (with limitations on the mark).
SYLLABUS/CONTENT
The impact of noise and vibration on society
 Impact of noise exposure
 Impact of vibration
 Standards and regulations
Key acoustic concepts and descriptors
 Sound pressure, particle velocity, sound intensity and sound power
 Vibration displacement, velocity, and acceleration
 Strength descriptors: Amplitude, root mean square and the level concept
 Frequency and frequency spectrum.
 Plane wave, spherical wave, wavelength, sound speed
Some useful math and how to use it in acoustics
 Linear systems and frequency response function
 Complex quantities and the socalled iωmethod
 Fourier transformation – From time signals to frequency spectra
The acoustic wave equation and some of its solutions
 From basic equations to the linear wave equation for fluid media
 Plane and spherical wave solutions to the linear wave equation
 Concept of specific acoustic impedance
 Sound intensity in plane and spherical waves
Reflection and transmission of plane sound wave
 Reflection and transmission of plane sound waves – Normal and oblique incidence
 Standing waves
 Resonant sound fields
Vibrations and structureborne sound – How acoustic energy is transmitted via vibration
 Quasilongitudinal waves in rods
 Bending waves in beams and plates
 Torsional waves in shafts
 Resonant vibration fields
Statistical room acoustics
 Sabine’s statistical room acoustics model
 Room reverberation time – Acoustic absorption and equivalent absorption area
 Direct field and reverberant field
 Sound transmission between rooms
Acoustic radiation modes
 Acoustic monopoles and dipoles
 Acoustic radiation from vibrating surfaces
 Radiation efficiency
 Influence of reflecting surfaces
Vibration isolation – How to reduce structureborne sound transmission
 Vibration isolation efficiency measure – Insertion loss
 Vibration isolation: Point massMassless springRigid foundation model
 Vibration isolation: Mobility model
Duct silencers – How to reduce noise from duct flow pulsations
 Silencer efficiency: Transmission loss and insertion loss
 Reactive duct silencer systems
 Resistive silencers
 Reactive vs resistive silencer elements
How to design quiet processes – The excitation force characteristics vs perceived noise
 Some rules of thumb for designing products with low perceived noise levels
Two measurement exercises
RECOMMENDED READING/BIBLIOGRAPHY
Course book: Sound and Vibration, Wallin et al
Collection of problems with suggested solutions and answers
TEACHERS AND EXAM BOARD
Ricevimento: Whenever required during normal working hours. Questions can be posed by mail and face to face meetings can be arranged by appointment (in presence or by videoconnection).
Exam Board
ULF CARLSSON (President)
ULF ERIK ORRENIUS (President Substitute)
ENRICO RIZZUTO (President Substitute)
CORRADO SCHENONE (President Substitute)
LESSONS
LESSONS START
See the official calendar of the Polytechnic School
Class schedule
L'orario di tutti gli insegnamenti è consultabile all'indirizzo EasyAcademy.
EXAMS
EXAM DESCRIPTION
Written final exam
The written exam has a problemsolving part and a theoretical/conceptual essay part.
The problemsolving part consists of three problemsolving tasks with 10 pts each. Two tasks on basic level and the third on more advanced level.
The essay part consists of two short essay tasks, 5 pts each, intended to examine the understanding of important concepts.
Total maximum 40 pts on the written exam.
“Continuous” short exams
Three short written exams, during the course are given to promote continuous learning. Each short exam contains one, 5 pts, short essay task and one, 10 pts, problemsolving task. The essay task is passed with 3 pts or more. The problemsolving task is passed with 6 pts or more.
 Pass on all three short written exam’s essay tasks gives 2x5 pts = 10 pts on the final written exam essay tasks.
 Pass on two out of three short written exam’s essay tasks gives 5 pts on the written exam’s 1st or 2nd essay tasks. Hence, only one of the essay tasks of the final exam, needs to be done.
 Pass on one essay task gives 0 pts on the written exam essay tasks. Hence, both essay tasks on the final exam needs to be done.
 Pass on three problemsolving tasks gives 2x10 pts = 20 pts on the written exam's 1st and 2nd problem solving tasks. Hence, only the last problemsolving task of the final exam needs to be done.
 Pass on two problemsolving tasks gives 10 pts on the written exam's 1st or 2nd problemsolving task. Hence, one of the final exams problemsolving tasks can be skipped.
 Pass on one problemsolving task gives 0 pts on the written exam. Hence, all three problemsolving tasks on the final exam needs to be done.
Hence, passing the three short exams allows to complete the course, but limits the outcome to mark 24.
Grading
 Mark 30 for 38,5pts ≤ Sum pts ≤ 40pts
 Mark 29 for 37,5pts ≤ Sum pts < 38,5pts
 Mark 28 for 36,5pts ≤ Sum pts < 37,5pts
 Mark 27 for 35,5pts ≤ Sum pts < 36,5pts
 Mark 26 for 34pts ≤ Sum pts < 35,5pts
 Mark 25 for 32,5pts ≤ Sum pts < 34pts
 Mark 24 for 31,5pts ≤ Sum pts < 32,5pts
 Mark 23 for 30,5pts ≤ Sum pts < 31,5pts
 Mark 22 for 29pts ≤ Sum pts < 30,5pts
 Mark 21 for 27,5pts ≤ Sum pts < 29pts
 Mark 20 for 26pts ≤ Sum pts < 27,5pts
 Mark 19 for 24,5pts ≤ Sum pts < 26pts
 Mark 18 for 23pts ≤ Sum pts < 24,5pts
ASSESSMENT METHODS
The theoretical/conceptual part evaluates the quality of the examinee’s understanding of important concepts in acoustics.
The problemsolving part evaluates the examinee’s understanding and skills to choose appropriate models and apply them to analyse a given acoustics problem.
Exam schedule
Data  Ora  Luogo  Degree type  Note 

30/01/2024  10:00  GENOVA  Scritto + Orale  
15/02/2024  10:00  GENOVA  Scritto + Orale  
28/05/2024  10:00  GENOVA  Scritto + Orale  
13/06/2024  10:00  GENOVA  Scritto + Orale  
12/09/2024  10:00  GENOVA  Scritto + Orale 
FURTHER INFORMATION
None