Study on the acoustic similitude of the underwater complex shell structure

Abstract

The underwater noise that is produced by the underwater complex shell structure is a basic question to be solved for the noise control of an underwater structure. One way to study and control the underwater noise of the underwater complex shell structure is the experiment of vibration and sound radiation of all kinds of scaled-down models for its prototype. This method can predict vibration and sound radiation of an underwater complex shell structure, and provides the necessary parameters for the design of noise control. Using the finite-element method and the spherical function spread method, this paper investigates the similitude of coupled vibration and acoustic radiation for the typical structure of an underwater vehicle (elastic ring-stiffened cylindrical shell with hemispherical caps on the ends), and presents acoustic similitude conditions and relationships of the structures. At the same time, the acoustic scale effect and boundary effect, which are influenced by loss factors, shear and rotatory inertia, and surface sound reflection are investigated in detail. The results show that these effects can be controlled with similitude model designing and experiment design.