Analysis Of Fluid Structure Interaction For Ply Stucture Of Composite Wind Turbine Blade

As a key component in wind turbine blade, performance of blade directly affects the reliability of the machine. For engineering design, the accurate analysis of blade structure and aerodynamic performance is self-evident. Currently, which the main research is based on the integrated intensity of the blade, it ignores the truly local blade features; plus, blade momentum theory (BEM) is to obtain the same aerodynamic performance of blade between sections, which between blade sections near the leading edge and trailing edge the aerodynamic force may exist bigger difference, since these sections actually suffer aerodynamic performance complexly. For these problems, paper provides a method of preliminary ply design and verifies the ply structure through the establishment of ply structure finite element model. In order to more accurate analysis of the ply structure, considering the coupling interaction between structure and fluid, the fluid-structure interaction analysis is analyzed, which the result is compared with the experimental values. Later, dynamic characteristics of the ply structure of the blade are analyzed combining the fluid structure interaction under the typical wind. The main research contents and conclusions are as follows:(1) Comparing the experimental data, the paper verifies the validity of the physical model of S809twisted blade and meshing plan. Thus, it proves the feasibility of method of establishing blade and the fluid domain’modeling, strategy of grid partitioning of twisted blade and the CFD analysis based on CFX.(2) The paper establishes the finite element modeling of ply structure after planning the ply structure of the blade and confirms that the ply design is reasonable combining with the BEM method and Tsai-Wu Failure Criterion. Under extreme wind speed of50m/s and normally regular wind speed of7m/s, the analysis from the BEM method and the one-way FSI is compared, which the result showed that the maximum stress from the analysis of FSI is less than from the analysis of BEM, respectively about36%and25%. There is a big difference between two results, but the maximum stress ply are at the same location of blades and the change of stress gradient is close to. Plus, under the extreme wind speed, the maximum tip displacement from the analysis of FSI is less than from the analysis of BEM, nearly about20%.(3) Under specific wind speed,7m/s, the one-way FSI and the two-way FSI is compared for the ply structure blade. Through experimental comparison, it showed that one-way FSI analysis has been able to accurately analyze the performance of the blade, and fewer a third of the total analysis time than the two-way FSI analysis. Considering the engineering application, one-way FSI analysis has been able to meet the design requirements.(4) Modal analysis of the ply structure of blade showed that the centrifugal force affects greatly to the first-order natural frequency, about8%of the differences, while the pre-stressed force of the pulsating wind load brings the small effects on natural frequency; Under the six typical wind speed, buckling analysis combining the FSI showed that the buckling factor is too big, which means that preliminary ply design needs to be further optimized.