|
|
Study of acoustic properties of enclosed rooms
Kovařík, Filip ; Fišarová, Zuzana (referee) ; Šťastník, Stanislav (advisor)
The bachelor thesis deals with the acoustics of enclosed spaces, its behaviour and impact on the clarity and quality of presentation. Here is written transmission of acoustic energy, behaviour of spatial and building acoustics, which builds their diagnostic methods. The work also includes legislative requirements stipulated by the acoustics of enclosed spaces and the achievement of these requirements using different types of acoustic absorption capacity of materials, applications, and more specifically their basic properties. In the experimental part, the measurement of reverberation time in a selected room and the adaptation of acoustic properties so that attained legislative requirements
|
|
|
Computational modelling of high-frequency noise inside cabin of aircraft EV-55M
Straka, Martin ; Pellant, Karel (referee) ; Švancara, Pavel (advisor)
This thesis describes methods of high frequency noise and vibrations computation of cabin part of EV–55M (aircraft developed by Evektor Kunovice). There is a brief summary of methods used for determining high frequency noise and vibrations in the first part of the thesis. Detailed explanation is given for Statistical Energy Analysis (SEA) which is nowadays the most dominant method in this area. The energy balance equation is derived in this chapter and SEA parameters such as modal density, damping loss factor, coupling loss factor and power input are introduced here. Next part deals with main noise sources of propeller driven and jet aircraft and passive and active noise controls are discussed. Practical part of this thesis deals with modeling aircraft EV–55M fuselage using VA One SEA module. Two models were created. First of them is only an outside fuselage with aircraft flooring and the second one is extended by interior trim panels and is applicable for simulation of noise control treatments. Computational modeling is accompanied by experimental measurement of passive noise control material characteristics. Postprocessing of information obtained from impedance tube measurement was performed in FOAM – X. Determined characteristics of porous material were used as inputs to VA One and reduction of sound pressure level in fuselage cavities by using noise control treatment was found. In conclusion there is a summary of noise transmission paths from sources to interior cavity and some treatments of them are simulated
|
|
|
Computational modelling of high-frequency noise inside cabin of aircraft EV-55M
Straka, Martin ; Pellant, Karel (referee) ; Švancara, Pavel (advisor)
This thesis describes methods of high frequency noise and vibrations computation of cabin part of EV–55M (aircraft developed by Evektor Kunovice). There is a brief summary of methods used for determining high frequency noise and vibrations in the first part of the thesis. Detailed explanation is given for Statistical Energy Analysis (SEA) which is nowadays the most dominant method in this area. The energy balance equation is derived in this chapter and SEA parameters such as modal density, damping loss factor, coupling loss factor and power input are introduced here. Next part deals with main noise sources of propeller driven and jet aircraft and passive and active noise controls are discussed. Practical part of this thesis deals with modeling aircraft EV–55M fuselage using VA One SEA module. Two models were created. First of them is only an outside fuselage with aircraft flooring and the second one is extended by interior trim panels and is applicable for simulation of noise control treatments. Computational modeling is accompanied by experimental measurement of passive noise control material characteristics. Postprocessing of information obtained from impedance tube measurement was performed in FOAM – X. Determined characteristics of porous material were used as inputs to VA One and reduction of sound pressure level in fuselage cavities by using noise control treatment was found. In conclusion there is a summary of noise transmission paths from sources to interior cavity and some treatments of them are simulated
|
|
|
Study of acoustic properties of enclosed rooms
Kovařík, Filip ; Fišarová, Zuzana (referee) ; Šťastník, Stanislav (advisor)
The bachelor thesis deals with the acoustics of enclosed spaces, its behaviour and impact on the clarity and quality of presentation. Here is written transmission of acoustic energy, behaviour of spatial and building acoustics, which builds their diagnostic methods. The work also includes legislative requirements stipulated by the acoustics of enclosed spaces and the achievement of these requirements using different types of acoustic absorption capacity of materials, applications, and more specifically their basic properties. In the experimental part, the measurement of reverberation time in a selected room and the adaptation of acoustic properties so that attained legislative requirements
|
|
|
Návrh vnitřní akustické stěny
Turoňová, Světlana
The bachelor thesis includes a general description of the formation and propagation of sound, lists various types of acoustic materials. Thesis primarily addresses two different designs of acoustic walls (partition-walls) that separate the lecture hall from the lobby of a particular company building where the listeners gather for snacks. This installation of partition-wall acoustically separated lobby, which is disturbing to the lecture hall. The aim of the thesis is to experimentally design two variants of the walls using acoustic materials. There are described two different structured walls with prices calculations for a complete production and assembling. Acoustic walls are assembled out of different acoustic materials from various companies. Who offer their products on the Czech market.
|
guest ::
