超空泡水下航行体振动特性分析

Vibration of supercavitating underwater vehicles

用有限元方法分析了超空泡水下航行体的固有特性,计算了自由边界条件下超空泡航行体的振动特性,求出了固有频率和模态,并选取对其结构性能有重要影响的四类模态,即梁弯曲模态、呼吸模态、径向模态和轴向弯曲模态绘制了三维模态图。研究表明,超空泡水下航行体无阻尼自由振动的首阶模态为梁弯曲模态;呼吸模态发生的初始频率较高;径向模态发生的初始频率较低;轴向弯曲模态发生的频率比较集中,变形较为复杂。所得结果为今后开展进一步的超空泡航行体结构动力学研究提供了模型基础。

The natural characteristic of a supercavitating underwater vehicle was analyzed by FEM. And its vibrating characteristic on free boundary was calculated. The natural modes and frequencies were given. The four kinds of modes that were important to its structaral performance were selected including the bending mode as a beam, the mode as breathing, the radial mode and the axial bending mode. The three-dimensional figure of modes was described. The research shows that its first mode of undamped free vibration is the bending mode as a beam. The initial frequency of the modes as breathing is higher while which of the radial mode is lower. The frequencies of the axial bending modes are concentrated and their deformation is complex. The results provide the foundation for the future research of structural dynamics of supercavitating underwater vehicles.