International Journal of Aerospace and Lightweight Structures (IJALS)Volume 3 Number 1 (2013)
Prediction of Acoustic Power Transmission of Fluid-Filled Thin Pipe Based on Impedance-Mobility Approach
Science Town, Taejon 305-701, Korea.
Prediction of acoustic power transmission within a fluid-filled pipe system is not easy because of the coupling between acoustic field in the fluid and structural wave field. For regular shape structures, such as cylindrical pipe, an analytic method has a merit of explicitly reflecting related physical meaning and saving computer time, compared to finite element method. In this work, an analytic study on the acousto-structural coupling of a fluid-filled thin cylindrical pipe is carried out using the Impedance-Mobility Approach (IMA). For industrial cylindrical pipe with relatively large ratio of thick to radius, the other modes but beam mode is usually ignored. In order to predict the response of relatively thin cylindrical pipe, the curvature effects of a cylindrical shell are considered. Describing equations for such acousto-structural coupling are derived from the wave equation and the dynamic equation of a cylindrical shell. In order to validate the IMA model developed, the acousto-structural response of a cylindrical pipe filled with air is calculated using IMA and FEA, respectively, which reveals the good agreement between IMA and FEA results. Finally, the calculations of sound transmission loss for air-filled and heavy fluid-filled pipe are performed.
Keywords: Acousto-structural coupling, Impedance-mobility approach, Transmission loss.