船舶水下辐射噪声计算评估方法及应用

Evaluation Method and Application of Ship Underwater Radiation Noise Calculation

采用有限元(FEM)和边界元(BEM)相结合的方法对船舶水下辐射噪声进行研究。首先根据船舶的实际情况建立三维结构有限元模型,包括船体结构、压载、主要动力设备及其隔振方式等;然后结合实船测试的柴油发电机组、推进电机机脚振动和轴系中间支撑基座振动数值,以及船模试验得到的螺旋桨脉动压力,计算获得流固耦合下结构的响应;最后将船体外壳水线以下结构响应作为约束条件,通过边界元方法对水下辐射噪声进行计算和分析。对船舶设计阶段水下辐射噪声初步评估方法进行修正,同时与水下辐射噪声实船测试结果进行对比,结果显示修正后的计算评估方法计算准确性较高,能进一步提高设计阶段水下噪声的评估精度,可以为船舶水下辐射噪声控制提供依据和参考。

The finite element（FEM） and the boundary element method（BEM） are combined together to solve the underwater radiation noise of ships. Firstly, three-dimensional finite element model is established according to the actual ship, such as structure, ballast, prime power unit and types of vibration isolating. Secondly, combining the vibration velocity of diesel, generator and the middle support foundation from full scale testing, the fluctuating pressure from ship model test, the structural response is calculated under fluid-structure coupling. Finally, the boundary element model is employed to calculate the underwater radiation noise. The outer surface of finite element model is treated as the velocity boundary condition for calculation under water radiation noise. Preliminary assessment methods of underwater radiation noise are revised at the ship design stage. After that, the assessment methods have a higher calculation accuracy contrast to the result of full scale testing. It provides the basis and reference for ship underwater radiation noise control.