International Congress on Sound and Vibration (ICSV16) edition:16 location:Krakow, Poland date:5-9 July 2009
Acoustic networks models are ideally suited for the aeroacoustic design of duct systems such as automotive exhaust systems, HVAC-ducts,. . . Acoustic absorbent materials are commonly used for these types of applications in order to further improve the acoustic attenuation. For the characterization of the acoustic properties of these materials, accurate prediction techniques for the acoustic impedance in a non-quiescent medium are needed. This paper focuses on the indirect determination of the acoustic parameters such as transmission loss and grazing flow impedance of lined ducts with various types of mean flow using a linear network representation which can be easily obtained numerically and experimentally. In a next step, the determined acoustic properties are used to evaluate the transmission characteristics of more complex duct configurations. In this way, the proposed methodology offers a strong design tool for the determination of the aeroacoustic properties for confined subsonic flow applications.