Analysis Of Fluid-structure Interaction Characteristics Under Non-uniform Flow Of Propeller

At present,propellers are widely used in ships,but the deformation of the blades in actual work may cause performance degradation.In recent years,the research on fluid-structure interaction of propellers has received extensive attention.In this paper,using ANSYS-workbench,the method of combining finite element and computational fluid dynamics is used to analyze the fluid-structure interaction of the propeller.In the first part of this paper,the hydrodynamic numerical method is verified.First,the grid independence was verified.By comparing the calculation results of rotating flow fields of different sizes,an appropriate rotating flow field size was selected.Four sets of grids of different densities were divided for comparison of the results,and a more accurate network was selected.The calcuation results of the DES model and the k- model are compared and the k- model is selected for subsequent calculations.Finally,the results of the literature are compared to verify the correctness of the numerical method in this paper.Then analyze the deformation characteristics of the propeller under uniform flow.In order to study the deformation characteristics of the elastic propeller,the hydrodynamic performance and blade deformation of propellers with different diameters and different Young’s modulus were calculated under different working conditions.And a dimensionless analysis of the deformation is carried out.Calculations from the literature show that the non-dimensional analysis method is reasonable and correct.At the same time,the influence of the size effect on the performance of the propeller is also studied,and it is found that the efficiency is greatly affected by the size effect.Finally,by comparing the one-way and two-way fluid-structure interaction deformations,it is found that the advancement coefficient has a greater influence on the deformation,and there is a trend that the advancement coefficient increases and the deformation difference decreases.The reason for this difference in deformation is that the one-way coupling does not consider the influence of the structure on the fluid.Then,the hydrodynamic analysis of the propeller under non-uniform flow is carried out,and the hydrodynamic calculation of the propeller under different flow speeds is carried out.Firstly,the velocity distribution diagrams of nominal wake and effective wake are analyzed.The effective wake is greatly affected by the speed coefficient,and the suction effect of the propeller is obvious under the low speed coefficient.Then the pressure distribution between the propellers is analyzed.The closer to the propeller’s central axis,the more severe the pressure changes.Finally,the unsteady performance of the propeller is calculated,and it is found that there is a certain difference between the propeller and the open water performance.The interaction of the propeller has a greater impact on thrust and torque,but has a small impact on efficiency.Finally,the fluid-structure interaction calculation of the propeller under uniform flow is carried out.Firstly,the influence of the deformation on the unsteady performance is analyzed.It is found that the thrust coefficient and the torque coefficient increase but the efficiency decreases.Then the different positions and positions on the blade surface are analyzed.The dynamic response of each point on the blade is greatly affected by the non-uniform flow field.Then the fluid-structure interaction mode of the propeller is analyzed,and it is found that no higher-order mode appears.Finally,the results of the uniform flow field and the non-uniform flow field are compared.It is found that the inhomogeneity of the inhomogeneous flow field has a great influence on the deformation.Through the calculation and analysis of the fluid-structure interaction of the propeller in this paper,the relevant conclusions of the fluid-structure interaction of the propeller are obtained,which provides a reference for the calculation of the fluid-structure interaction of the propeller.