基于流固耦合的船舶轴-桨耦合振动特性分析

以研究螺旋桨水动力和离心力对船舶轴-桨组合振动特性的影响为本文的研究目的,基于W o r k-bench平台,采用流固耦合有限元分析方法,进行船舶轴-桨组合模态分析.在CFX中计算螺旋桨敞水性能,并在Ansys中将螺旋桨叶面水压力和离心力作为预应力分析轴桨组合振动的固有频率和振型,比较轴系、螺旋桨单独模型和轴-桨组合模型在固有频率上的区别.计算结果表明,轴桨组合的固有频率远远低于轴系和螺旋桨独立模型的固有频率;轴-桨旋转产生的离心力对其固有频率影响不大;螺旋桨在流场中产生的水压力略微提高纵向振动固有频率,但影响很小,在实际应用中可以忽略.

Coupled vibration characteristic analysis of shaft-propeller system of ship based on fluid structure interaction

In order to explore the effect of propeller hydrodynamics and centrifugal force on coupled vibration charac-teristic of shaft-propeller system, taking Workbench as a tool, modal analysis of shaft-propeller system of ship was com-pleted with the fluid-structure interaction method. The open water performance of propeller was calculated in CFX, the natur-al frequency and mode shape of shaft-propeller system were analyzed in Ansys taking propeller water pressure and centrifu-gal force as pre-stress, and the difference of natural frequency of the single model of the shaft, the single model of the pro-peller and the combination model of shaft-propeller was analyzed. The results show that, the natural frequency of the shaft-propeller system is much lower than the natural frequency of the single model of the shaft and the single model of the pro-peller; the centrifugal force generated by the rotation of the shaft-propeller system has little effect on the natural frequency;the pre-stress produced by the propeller in the flow field increases the natural frequency of the longitudinal vibration slightly, but the influence is small, which can be ignored in the practical application.