Effect of longitudinal beams traversing edge-perforated bulkhead on underwater acoustic radiation of cylindrical shells

To investigate the effect of longitudinal beams traversing edge-perforated bulkhead on the underwater vibration and acoustic radiation of cylindrical shells, an approach combining the finite element and boundary element is proposed in this paper. Through FORTRAN and DMAP codes, the corresponding frequency response curves measuring the mean-square velocity and radiated sound power from cylindrical shells with different amount,radiuses,and distribution of holes are obtained,while the stiffened structure near the hole is purposely ignored. The results show that the distribution of holes hardly influences the decibels of mean-square velocity and radiated sound power, but it has significant impact on the peak numbers of the measuring indicators. On the other hand, the amount and radiuses of holes demonstrate great influences on the decibels of the measuring indicators as well as the peak numbers. Therefore, properly arranging the parameters of marginal holes is highly recommended in the submarine design.