A Basic Investigation of Resonance Characteristics of PW-OWC-Type WECs

This paper describes resonance characteristics of water regions of oscillating water column (OWC) type wave energy converter (WEC) models installed with projecting walls, which is called as a PW-OWC device. We can easily improve power take-off (PTO) performance of an OWC-type WEC device by installing projecting walls on in front of it. One of the reasons of it is that such as the device can have multi-resonance frequencies. Behaviors of the resonances are complicated because we can change the resonance characteristic by varying a damping effect which decides a PTO characteristic. The thing would be that we can easily optimize the characteristic to a sea wave condition. However, the resonance characteristics have not clarified yet. The paper shows the resonance behaviors of OWC and a water region surrounded by the projecting walls (PWs). The paper used not only the linear potential theory-based prediction method for OWC-type WECs but also the dynamic absorber model with the tuned mass damper model in order to predict the primary conversion performance of OWC WECs. The paper shows validation of both calculation approaches by comparing each other. As a result, there were two cases which are that one was a case with two resonance frequencies and another case had only one resonance because of damper magnitude as PTO.