A finite element+boundary element-modified modal decomposition method for vibration and sound radiation from submerged revolutional shells

A Finite Element + Boundary Element-Modified Modal Decomposition method (FBMMD) is presented for predicting the vibration and sound radiation from submerged revolution-al shell. Improvement has been made in FBMD Method to accelerate the convergence by introducing the residual mode which takes into account the quasi-state contribution of all neglected modes. As an example, the vibration and sound radiation of a submerged spherical shell excited by axisymmetric force are studied in case of Ka = l, 2, 3 and 4. From the calculated results we see that the FBMMD method shows a very significant improvement to the accuracy of surface sound pressure, normal displaoement and far-field pattern of sound radiation, especially to the results of far-field pattern.