Research Of Radiation Mechanisms Of Submarine Sail Structures

Submarine sail is one of the main noise sources of submarine. This thesis mainly focus on the machanics and the charicteristics of noise of the submarine sail. The context of this paper has two parts. In the first part,the characteristic of flow field out of the simple model of sail has been calculated by CFD (Computational Fluid Dynamic) method . The instances include different shape of the model and different velocity of the flow field. Then the spatial distribution characteristics of time-averaged physical quantities of the flow field around fairwater model are obtained. In the second part, the vibration characteristic of the model under water has been calculated by FEM (Finite Element Method)+IBEM(Indirect Boundary Element Method) method. The radiated sound power from this model is also calculated by BEM. The effect of main factors,such as the thickness of the model,the distribution of symmetric forces excited on the model, and different kind of ribs,on the radiated sound power has been analyzed.Based on the results above, the relationship between the outer flow field,the shape and the vibration characteristics of the model of the submarine sail is obtained, which can be referenced to the submarine sail noise control.