Vibroacoustic Performance of a Stiffened Plate With Perforation Under the Excitation of Turbulent Boundary Layer

Abstract Perforated plate is an essential part of underwater vehicles. Investigation on its sound and vibration characteristics has significant influences on the performance of the underwater vehicles. Premised on the fluid-solid interaction, this article presents the vibroacoustic performance of a stiffened plate with perforation under the excitation of turbulent boundary layer (TBL) with the finite element approach. The TBL excitation in the form of dynamic pressure is calculated by using the CFD technique. By analyzing the properties of the excitation at different location versus frequency, the intrinsic frequency and mode shapes, and vibration and sound radiation of the stiffened perforated plate, it is found that the dynamic pressure attenuates dramatically along with the frequency, multiple natural modes of the stiffened perforated plates are evoked which radiates sound to the adjacent fluids. Due to the strong stiffeners, there are several vibration modes which strongly radiate sound within the areas among the stiffeners. The mechanism of the radiation peaks is stated that the radiation efficiency of a surface vibration mode is much higher than that of a dipole and quadrupole vibration mode. This work provides guidance for the optimization and implementation for the stiffened perforated plate in underwater vehicles.