Numerical Verification of the Tuned Inertial Mass Effect of a Wave Energy Converter

This paper introduces the mechanism of a buoy-type wave energy converter (WEC) with a tuned inertial mass (TIM) mechanism. The TIM mechanism consists of a rotational mass and motor connected in series with a tuning spring. While it is common to control the current of the power take-off system, the stiffness of the spring is tuned in addition so that the inertial mass part resonates with the dominant frequency of the wave motion. The method to design the parameters to maximize the power generation capability is introduced and numerical studies for both narrowband and broadband sea states are carried out. It is shown that the proposed device demonstrates better energy harvesting performance compared to the WEC without the TIM mechanism to band-limited stationary random vibration.