The effect of the self-induced vibration of a localized elastic airfoil on the aerodynamic performance of the airfoil at Reynolds number=2×10
5
is studied numerically. In particular
the influence on the lift enhancement and drag reduction of the airfoil is analyzed. An aero-elastic model of the localized elastic airfoil is established following the theory of shallow arch with geometric nonlinearity and aerodynamics
and an algorithm for the aero-elastic model is developed under the ALE framework. Furthermore
the case of unsteady flow around oscillating NACA0012 airfoil is simulated via the presented algorithm
and the lift coefficients are in good agreement with the data from the literature
which verifies the accuracy and feasibility of
the algorithm for unsteady flow. The effect of the self-induced vibration of the structure on aerodynamic performance of the airfoil is investigated numerically. The results show that the aerodynamic performance of the localized elastic airfoil is improved greatly compared with the rigid airfoil. The stall angle is delayed from 13° to 16° and the lift-to-drag ratio increases by more than 80% due to the self-induced vibration of the localized elastic airfoil. Adopting FFT analysis
the synchronization between the vibration of the airfoil and the evolution of the unsteady flow occurs at the attack angles of 8° and 11°
respectively. As the attack angle is 16°
a series of small-sized vortices is formed in the shear layer and the size of the large eddy is decreased
which reduces the fluctuation amplitude of the lift and drag significantly and improves the aerodynamic performance accordingly.
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references
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