In this study, the blade of a distributed horizontal axis wind turbine was selected as the research model and its stiffness, damping ratio and natural frequency were improved for the first time by airfoil concave on the premise of not reducing the blade power output under the rated working condition.The research revealed that the airfoil’s inner concave on the suction surface could better control the position and influence range of airflow convergence on suction surface, and combined with the inducing effect of grooves on the convergence streamline, it can reduce the energy loss of airflow to a certain extent and improve the blade’s aerodynamic performance.In addition, the airfoil concave can significantly increase 1st-order and 2nd-order damping ratios of the wind wheel by 3%— 9%, increase the stiffness value of the blade by 32%, and effectively reduce the maximum displacement and the maximum strain of the blade by 28% and 19%, respectively.Successful application of airfoil concave in the design of wind turbine blades will not only provide a new method for the derivation of airfoil family, but can also provide a new way for synchronous optimization of the aerodynamic performance and structural dynamic performance of the blade.
Key words
blade /
airfoil concave /
capability of doing work /
stiffness /
damping ratio /
displacement /
strain.
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