Aktive intensitätsbasierte Minimierung der Schalltransmission durch ein teilgeöffnetes Fenster
Publication date
2025-08-25
Document type
Dissertation
Author
Sandner, Michael
Advisor
Referee
Monner, Hans Peter
Granting institution
Helmut-Schmidt-Universität/Universität der Bundeswehr Hamburg
Exam date
2024-09-02
Organisational unit
Publisher
Universitätsbibliothek der HSU/UniBw H
Part of the university bibliography
✅
Language
German
Keyword
Lärmbelastung
Schallübertragung
Teilgeöffnetes Fenster
Aktive Schallreduktion
ANC
ANR
Aktive Lärmunterdrückung
Schalltransmission
Analytische Schallberechnung
Adaptive Geräuschreduktion
Intensitätsbasierter Algorithmus
Abstract
Urbanization and the resulting problems are a major challenge for a large part of the inhabitants of cities and furthermore for the planet. The population of many cities around the world such as Beijing, China or Hamburg, Germany have been steadily increasing for several years. In addition to increasing CO2 emissions through rising numbers of private transport, the increase of sound pollution in urban areas contributes to environmental pollution. High noise levels have been shown to have a negative impact on health, especially cardiovascular diseases.
As a conclusion, there are limit values to be observed in many countries in order to reduce noise, for example in the construction industry. In Hamburg there is a so-called ”Hafen-City-Clause”, which ensures that a noise level of 30dB(A) is not exceeded at night when the windows in bedrooms are partially open. Standard windows often do not achieve a sufficient reduction in sound transmission to be able to comply with this limit value.
The sound transmission can be minimized by the use of passive measures, but this is accompanied by a restriction of the ventilation through the partially open window. In order to enable unrestricted air circulation, active systems, so-called Active-Noise-Control (ANC) systems, can be used. These systems can be placed in the sound transmission path and reduce noise through destructive interference without restricting airflow of the window.
To design an effective active system it is necessary to examine the influence of sound transmission paths on transmitted noise. For further investigation of sound transmission, the complex geometry of a partially open window is simplified to a parameterizable two-dimensional gap.
The transmission of noise is calculated analytically in a first step with a substitute model, from which requirements for an active system are drawn. In order to get a deeper understanding of the influence of a sound path on sound transmission, the influence of parameters of a small gap in relation to the wavelength and the influence of a control signal of an anti-noise source on sound transmission are investigated.
As a result of the conducted analytical and numerical studies, an alternative approach of an algorithm for adaptive intensity-based noise reduction is introduced. In this approach, only sensors placed in the gap are used to reduce the transmission of sound. The presented approach is finally implemented in a rapid control prototyping system and the functionality is proven by an experiment.
As a conclusion, there are limit values to be observed in many countries in order to reduce noise, for example in the construction industry. In Hamburg there is a so-called ”Hafen-City-Clause”, which ensures that a noise level of 30dB(A) is not exceeded at night when the windows in bedrooms are partially open. Standard windows often do not achieve a sufficient reduction in sound transmission to be able to comply with this limit value.
The sound transmission can be minimized by the use of passive measures, but this is accompanied by a restriction of the ventilation through the partially open window. In order to enable unrestricted air circulation, active systems, so-called Active-Noise-Control (ANC) systems, can be used. These systems can be placed in the sound transmission path and reduce noise through destructive interference without restricting airflow of the window.
To design an effective active system it is necessary to examine the influence of sound transmission paths on transmitted noise. For further investigation of sound transmission, the complex geometry of a partially open window is simplified to a parameterizable two-dimensional gap.
The transmission of noise is calculated analytically in a first step with a substitute model, from which requirements for an active system are drawn. In order to get a deeper understanding of the influence of a sound path on sound transmission, the influence of parameters of a small gap in relation to the wavelength and the influence of a control signal of an anti-noise source on sound transmission are investigated.
As a result of the conducted analytical and numerical studies, an alternative approach of an algorithm for adaptive intensity-based noise reduction is introduced. In this approach, only sensors placed in the gap are used to reduce the transmission of sound. The presented approach is finally implemented in a rapid control prototyping system and the functionality is proven by an experiment.
Version
Published version
Access right on openHSU
Open access