Gyro Effect of Rotating Blades on the Floating Wind Turbine Platform in Waves

Offshore floating wind turbine system has been proposed by many researchers recently. It is important to clear wave response of the floating wind turbine system and to reduce its responses. This paper focuses on the gyroscopic effect of wind turbine on wave responses of the floating platform. A pontoon model having automatic revolving disk on the top, in waves is examined. The pitching motion reduction of floating pontoon model due to revolving disk is observed in experiments. Numerical results show that the peak frequency of surge and pitch motion is shifted to higher frequency side due to revolving disk on the top. But the revolving disk induces yaw motion as gyroscopic effect. The gyroscopic effect on steady drift forces and yaw moment is confirmed numerically. But this effect for the proposed SPAR is small in present calculation.