Course detail
Vibrations and Noise
FSI-RVHAcad. year: 2012/2013
Vibrations and noise are a general accompaniment to all machinery operations. The whole chain encompassing the vibration sources, transfer paths of the structure, noise emitters on the machine surface and ambient acoustic environment needs to be analyzed. We need to mainly focus on active methods of reducing vibrations and noise.
Basic areas of examination:
Spectra of vibro-acoustic quantities, experimental analysis,
biomechanics of the human voice and hearing, acoustic properties of closed areas.
Identification of sources of vibrations and noise, aerodynamic sources of noise.
Passive methods of noise reduction.
Active methods of noise reduction - vibroacoustic systems of machines, deterministic models (modelled by means of FEM ) for low-frequency noise), statistic models (solutions of high-frequency noise).
Language of instruction
Number of ECTS credits
Mode of study
Guarantor
Learning outcomes of the course unit
Prerequisites
acoustic wave, acoustic quantities (pressure, intenzity, power), acoustic cavities, acoustic signal spectra, experimental analysis of the acoustic quantities, acoustic fields, spectral and modal properties of acoustic cavities.
Mathematics:
matrix algebra, linear algebra, trigonometrical functions, programming on computers,computer modeling of mechanical structure.
Co-requisites
Planned learning activities and teaching methods
Assesment methods and criteria linked to learning outcomes
The claims for accreditation:
100 % attendance on the exercises. In case of the orderly excused absence is necessary to solve a alternate problem. Accreditation is carried out by means of the written test at the term end. The test consists of the three questions covered a very important areas of the acoustics subject. Participation on the exercises is compulsory. Head of exercises carry out continuous check of student’s presence , their activity and fundamental knowledge. A not excused presence in the exercise is a reason not to give the accreditation. Definite form of the fulfilment of these claims defines the head of exercises in the term begin.
Course curriculum
2. Spectra of acoustic variables : band pass, tracking,
multispectra
3.Acoustic properties of a closed areas
4.-5. Biomechanics of a human voice and hearing
6.Experimental identification of machine acoustic power
7.Aerodynamic noise sources, principles and examples
8.Passive methods of vibration and noise reduction
9.Principle of reactive dampers of pipe systems
10-11.Deterministic models of vibroacoustic machine systems:
- the coupling structure of vibroacoustic machine systems
- the methods of solution (FEM and BEM)
12-13. Statistical models of vibroacoustic systems (method SEA)
Work placements
Aims
Specification of controlled education, way of implementation and compensation for absences
Recommended optional programme components
Prerequisites and corequisites
Basic literature
Recommended reading
Classification of course in study plans
Type of course unit
Lecture
Teacher / Lecturer
Syllabus
2. Spectra of acoustic variables : band pass, tracking,
multispectra
3.Acoustic properties of a closed areas
4.-5. Biomechanics of a human voice and hearing
6.Experimental identification of machine acoustic power
7.Aerodynamic noise sources, principles and examples
8.Passive methods of vibration and noise reduction
9.Principle of reactive dampers of pipe systems
10-11.Deterministic models of vibroacoustic machine systems:
- the coupling structure of vibroacoustic machine systems
- the methods of solution (FEM and BEM)
12-13. Statistical models of vibroacoustic systems (method SEA)
Computer-assisted exercise
Teacher / Lecturer
Syllabus
2. Spectral and modal properties of cavities
3. Human voice analysis, its generation, vowel formants
4. Source noise identification, acoustic emitters
5. Acoustic power emitted by the machine
6. Aerodynamic noise sources - blowers, compressors
7. Calculation of the simple reactive noise absorber
8.-9. Deterministic models: solved by FEM
10.-11. Deterministic models: solved by BEM
20.Statistical models, modeling of model subsystems
13.Credit