Aeroelastic Coupling Evolutionary Mechanism Of Turbine Blades

Extending wind turbine is the current trend,and the turbine tends to be slender and flexible,which leads to a large deformation under airload,thus causing changes in aerodynamic characteristics of turbine and forming aeroelastic response process in which the airload of the turbine is coupled with the deformation of the turbine.For the sake of safety and economy of the turbine,it is necessary to study the aeroelastic characteristics of a large wind turbine.Similarity criterion which is based on aeroelastic model make three dimensional turbine of the aeroelastic coupling response to two dimensional model on pitch and plunge.According to the criterion,aeroelastic coupling response equation has been built and combines with CFD implemented two-degree-of freedom aeroelastic coupling responseAs the research object wind turbine DU 93-W-210 was adopted,this article first studied the airfoil at different attack angles of two degree of freedom under the coupling response time history,according to the motion of airfoil,determine the critical flutter velocity under different Angle of attack,research shows that with the increase of Angle of attack,the critical flutter velocity decreases,standing for more unstable phenomenon,aeroelastic unstable region is the same in two directions of pitch and plunge.Next,has carried out two degrees of freedom parameter,the influence of the aeroelastic system unstable regions including the torsion center position,the initial disturbance and the natural frequency of two degrees of freedom than,studies show that torsional center critical flutter speed will increase when placed in the front,means that the gas spring unstable oscillations are delayed or suppressed,and the torsion center on the trailing edge has no effect on the critical flutter velocity;In the pitch direction adding +5° of the initial perturbation will reduce the critical flutter velocity.In the pitch direction adding-5°of the initial perturbation will have a different response.Changing the natural frequency ratio,the unstable region of the pitch and plunge is no longer consistent,and the flutter suppressed is generally.The above research will provide theoretical guidance for flexible turbine aeroelastic design.Figure 56;Table 3;Reference 50...