Research Of Laminate And Fluid-structure Interaction On A Composite Tidal Current Energy Turbine

The world energy development is facing the great challenges such as steady supply,ecological environment and global climate change issue.Marine energy as abundant green,clean and sustainable renewable energy,its development and utilization has become a hot issue of science.In this paper,a theoretical study and experimental verification of composite turbine blade for a new type of bidirectional tidal current energy generator are presented.First of all,based on the principle of stiffness of composite material determined by the stress-strain relationship of orthotropic material,the Ansys Composite Pre Post(ACP)software module is used to calculate the stiffness properties of the special laminates.The general law of the elastic engineering constant change of ply angle ? is obtained.The finite element model of turbine blade with diameter of 1.5m is created for computer aided analysis.Then,on the basis of the finite element numerical method,the structural strength of composite blade is calculated and analyzed by using Ansys Static Structure.The maximum equivalent stress is 8.39 MPa and the maximum deformation is 11.1mm.The structural failure of the composite material leaves does not occur under the design load.The static test shows that the deformation data at each radius of the blade under the same load are in good agreement with the numerical calculation.The Ansys Modal module was used to analyze the 8 order vibration modes of composite material blade with different laminates.It is pointed out that most of the modes are flexural vibration,bending vibration has a great influence on the vibration of composite blade,the natural frequencies of each stage show different trends with the change of ply angle ?.However,the first order natural frequencies of all kinds of composite blades exceed the turbine blade operating frequency(0.25Hz),which avoids the possibility of resonance.Finally,on the basis of computational fluid dynamics(CFD)method,fluid solid coupling theory and Ansys Workbench platform,data is transferred from CFX to Static Structure.The fluid solid initeraction analysis of the composite blade with different laminates is carried out,and the hydrodynamic performance of the turbine blade under various conditions is obtained.The structural response of composite blade and metal blade under maximum working condition was compared.According to the composite Tsai-Wu criterion,the failure of composite blade is not checked.The trend of the change of leaf Tsai-Wu index by layer by layer in different layers was obtained.