船舶水下辐射噪声特性研究

本文采用有限元/边界元(FEM/BEM)方法对船舶水下辐射噪声特性进行研究.首先应用五种类型的有限单元建立了接近于真实船舶结构的有限元模型(包括机舱动力设备),并应用有限元法完成了流-固耦合状态下,船舶结构振动位移响应数值计算.然后将有限元模型的外表面处理成边界元模型,并由船舶外表面位移响应计算得到用于水下辐射噪声计算的速度边界条件.最后利用边界元技术对船舶水下辐射噪声特性进行研究.本文预估了仅考虑推进柴油机激励、柴油发电机组激励、齿轮箱激励以及所有激励情况下的船舶水下辐射噪声,并将其数值计算与实际测量结果比较,比较结果符合良好.

Study on characteristics of ship underwater radiation noise

The finite element (FEM) and the boundary element method (BEM) are combined together to solve the underwater radiation noise of ships. First,a finite element model of entire ship including power plant in engine room is built by using 30 geometric parameters and five kinds of finite elements,such as SHELL63, BEAM4,SOLID95,COMBIN14 and MASS21.Finite element method is employed to analyze the vibration responses of ship to excitations in consideration of fluid-structure interaction.Then,the outer surface of finite element model is treated as the boundary element model and the vibration displacement responses of the ship surface are treated as the velocity boundary condition for calculation underwater radiation noise.Boundary element method is employed to calculate the underwater radiation noise.In this paper,the underwater radiation noise of ship to propulsion diesel engine,auxiliary diesel energy or gearbox excitations have been predicted respectively.And, total sound pressure levels of ship underwater radiation noise to all excitations have been calculated during design phase and show a good agreement with experimentally measured results.