The fast multipole boundary element method (FMBEM) was developed to predict the ship cabin’s noise. Considering the vibration, rigid and impendence boundary conditions, the sound pressure contours on the surface and the SPLs at the monitoring point were calculated. The numerical method was validated by comparing the data with the numerical results from Virtual.Lab acoustics software. In addition, the FMBEM was proved efficient for the acoustic computations of large scale problems through comparison of computer time consuming of the FMBEM with that of the conventional BEM.

( College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001, China )
Abstract : The finite element method is used to calculate the internal sound field of a silencer, the mode waves are decomposed based on the acoustic mode theory, and then the transmission loss is determined. Based on the same theory, the transmission loss is measured through wave decomposition method with multi-sensors. It is found that results of the experimental measurement agree well with those of the numerical predictions. The effective frequency range for prediction and measurement of transmission loss are both extended beyond the cut-off frequency.