Study On Performance Of Composite Propellers Based On Fluid And Structure Interaction

As a new kind of propeller, composite propeller is playing a more and more significant role in energy saving and emission reduction of ships. Taking advantage of the designability characteristic of the composite propeller, reasonable arrangements of fiber direction and layer sequence of propeller blades could be made so that these propeller blades could produce transformation, which favors the hydrodynamic performance of propellers under hydrodynamic loads. Considering the characteristics of composite propellers, the traditional model test method has the disadvantage of high costs and long cycle, while CFD numerical simulation method has the disadvantage of being unable to take into account the influence of the propeller blade transformation on the hydrodynamic performance of the propellers. The fluid-solid coupling method,which is more closer to the physical phenomena,is therefore presented. According to the marine propeller theory, Computational Fluid Dynamics, and Structure Finite Element Method, this thesis establishes the fluid-solid coupling numerical simulation method of propellers in the open water and therefore completes the numerical computation method of composite propellers. The main contents are as follows:Clarifying the significance of fluid-solid coupling effects of working on propellers made of different materials. Reviewing the related theory of Computational Fluid Dynamics,Structure Finite Element Method, and Fluid-Solid Coupling about fluid-solid coupling effects on the numerical calculation of the propellers.Combining Computational Fluid Dynamics based on the theory of vicious flow and structural finite element analysis method. Establishing the fluid-solid coupling numerical method of propellers. Making comparative analysis of the new method and the traditional CFD method. Verifying the reliability of the new method from multi-angle.Using the newly-built fluid-solid coupling numerical method of propellers to make numerical calculations of propellers made of different materials irrespective of material anisotropic, make comparative analysis of the transformations?hydrodynamic performance,blade equivalent stress distribution and wake flow field of the propellers under typical working conditions. Analyzing the influence of the key parameters of material on the efficiency of marine propellers under typical working conditions.Using composite material analysis module to build layer structure of composite propeller,together with fluid-solid coupling numerical method, to build fluid-solid coupling numerical computation method of composite propellers. Making calculations of the propellers of three typical composite material layer forms, and comparative analysis of the influences of these three typical composite material layer forms on the hydrodynamic performance of the propellers. Providing evidence for the design of the layer structure of composite propeller.According to the above research, the fluid-solid coupling numerical method, established in this thesis,has the advantage of working on composite propeller. This thesis summarizes the influence of different materials on the hydrodynamic performance of marine propellers,thus providing a widely applicable method of optimal designing composite propeller.