The Low-Noise Optimization of a SWATH Ship's Structures Based on the Three-Dimensional Sono-Elasticity of Ships

摘要

Basic equations and numerical methods are presented for the three-dimensional sono-elasticity theory of ships in shallow sea Pekeris acoustic waveguide environment. The corresponding software three-dimensional hydroelastic analysis of floating and traveling structures-Acoustic developedbased on this theory is used for low-noise optimization design of the strut structures of a 1500-ton small waterplane area twin hull (SWATH) ship. When the SWATH ship was moored in waves and laying down instruments for ocean survey, it was observed that the waves continuously beat the verticalside walls of the struts, resulting in structural vibration and acoustic radiation in the frequency band below 100 Hz. This is a new phenomenon that the hydroelastic response of a local structure disturbs ocean survey performance. This phenomenon is not good for the performance of underwateracoustic equipment because it increases the background noise in the vicinity of the SWATH ship. This problem needs a low-cost and feasible solution. The mechanism of this phenomenon is first discussed by means of a sono-elastic analysis. After a series of low-noise design calculations forthe strut structures, a design of optimal acoustic performance is obtained with only a small increase in the structure weight. Some suggestions on engineering design for solving such problems are also put forward.