Study on effect of dynamic lubricated bearing oil film stiffness on underwater structure acoustic radiation induced by propeller force

When propeller runs in the unsteady wake flow field, the exciting force can form in the propeller blades. Such propeller exciting force transfers from the shafting, bearing supporting to the structure, causes the underwater structure strong vibration and noise. The vibration of propeller-shafting-structure coupled system is one of the main sources of underwater structure radiated noise now. Different oil film stiffness will affect the input power transmission characteristics of coupled system severely, and then affect the vibration and noise analysis of underwater structure. In this paper, the finite element model of double cylindrical shell structure with shafting is built. The oil film stiffness is got by solving two-dimensional Reynolds equation based on finite difference method. The vibration and underwater noise radiation of the shell structure induced by propeller excite force are calculated by FEM/BEM. Finally, the effect of dynamic lubricated bearing oil film stiffness on underwater structure acoustic radiation induced by propeller force is analyzed.