By coupling the calculation of the unsteady aeroforce and the vibration response through the development of CFD/CSD (computational fluid dynamics/computational structure dynamics) tight coupling method

the Fluent code was calculated

and the data of structural response and dynamic load were exchanged by UDF (user defined function)and reading and writing the I/O (input/output) files. The aerodynamic characteristics and vibration response of the airfoil at the condition of pitching motion

plunging (flapping) motion and periodic alternating incoming flow were studied. Numerical results indicated that the aerodynamic load was periodic

showing a smoothing hysteresis curve in rotating process

and the flapping responses also showed a cyclical phenomenon

the pitching response showed slight oscillation at slight stall condition. At the deep stall condition

the aerodynamic load or structural response showed strong nonlinear oscillation

high frequency components were more obvious.