Abstract A semi-analytic dynamic model is developed for vibro-acoustic analysis of submerged coupled propeller-shaft-hull systems under propeller forces. The propeller, shaft and hull are idealized as a lumped mass, multi-span beam and ring-stiffened shell of revolution, respectively. Stern, middle and thrust bearings are simulated as spring-damping systems. The hull is firstly decomposed into many segments, which are treated as conical shells and analyzed through combining Flugge shell theory and power series method. The shaft is divided into three Timoshenko beams according to the bearings. By expanding acoustic pressure and velocity as Fourier series in circumferential direction, surface Helmholtz integral equation is reduced to line integral, and acoustic pressure is further expressed as displacements of segments after meshing the line to some 3-node isoparameter elements. Boundary conditions and continuity conditions modified by external acoustic pressure are orderly assembled to the dynamic model. As considering the hull as a ring-stiffened conical-cylindrical-spherical shell, vibro-acoustic results of present method are compared with ones of coupled finite element-boundary element method, and the accuracy and efficiency of developed dynamic model are demonstrated. Furthermore, parameter analysis reveals that breathing and beam modes are predominant for vibro-acoustic responses, and sound power is mainly dominated by the cylindrical compartment.

中文翻译：

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螺旋桨激励下螺旋桨-轴-壳耦合系统振动声学分析的半解析方法

摘要 建立了一个半解析动力学模型，用于在螺旋桨力作用下水下耦合的螺旋桨-轴-船体系统的振动声学分析。螺旋桨、轴和船体分别被理想化为集总质量、多跨梁和环筋旋转壳。船尾、中间和推力轴承被模拟为弹簧阻尼系统。首先将船体分解成许多段，将其作为圆锥壳处理，结合Flugge壳理论和幂级数方法进行分析。轴根据轴承分为三个铁木辛哥梁。通过将声压和声速沿圆周方向展开为傅里叶级数，将表面亥姆霍兹积分方程简化为线积分，声压进一步表示为线段与某些 3 节点等参数单元网格剖分后的段位移。由外部声压修改的边界条件和连续性条件有序地组装到动态模型中。将船体视为加筋的圆锥-圆柱-球壳，将本文方法的振动声学结果与有限元-边界元耦合法的结果进行了比较，验证了所建立动力学模型的准确性和效率。此外，参数分析表明呼吸和光束模式对振动声学响应占主导地位，声功率主要由圆柱形隔室主导。由外部声压修改的边界条件和连续性条件有序地组装到动态模型中。将船体视为加筋的圆锥-圆柱-球壳，将本文方法的振动声学结果与有限元-边界元耦合法的结果进行了比较，验证了所建立动力学模型的准确性和效率。此外，参数分析表明，呼吸和光束模式在振动声学响应中占主导地位，声功率主要由圆柱形隔室主导。由外部声压修改的边界条件和连续性条件有序地组装到动态模型中。将船体视为加筋的圆锥-圆柱-球壳，将本文方法的振动声学结果与有限元-边界元耦合法的结果进行了比较，验证了所建立动力学模型的准确性和效率。此外，参数分析表明，呼吸和光束模式在振动声学响应中占主导地位，声功率主要由圆柱形隔室主导。并证明了所开发的动态模型的准确性和效率。此外，参数分析表明，呼吸和光束模式在振动声学响应中占主导地位，声功率主要由圆柱形隔室主导。并证明了所开发的动态模型的准确性和效率。此外，参数分析表明，呼吸和光束模式在振动声学响应中占主导地位，声功率主要由圆柱形隔室主导。