Session: 05-05-02 Aquaculture and Related Technology II

Paper Number: 104669

104669 - A Basic Investigation of Resonance Characteristics of Water Regions of Pw-Owc Wecs 

This paper describes resonance characteristics of water regions of OWC type WEC models installed with projecting-walls, which is called as a PW-OWC device. We can easily improve PTO performance of an OWC type WEC device by installing projecting walls in front of it. One of the reasons for it is that such as device can have multi-resonance frequencies. Behaviours of the resonances are complex 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 of a sea wave condition. However, the resonance characteristics have not been clarified yet. The paper shows the resonance behaviours of OWC and a water region surrounded by the projecting-walls.

The paper adopted two theoretical approaches to predict the resonance characteristic. One is an approximate method in which a tuned mass damper model with two mass points. Another one is a potential theory-based model which can directly take into account of a damping effect due to PTO in boundary integral equations of the velocity potentials to be solved. The tuned mass damper model was very convenient to predict the motion behaviours of water regions and PTO performances.

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 the damper magnitude as PTO. Besides, the paper considers the effects of motions as a floating system.

Presenting Author: Tomoki Ikoma Nihon University

Presenting Author Biography: Name : Tomoki Ikoma (Professor and Dr. Eng.)
Age : 54 years of age in June of 2023

(March, 1997) completed the Ph.D. course of science & technology, Nihon University in Japan and received the Ph.D. in engineer from Nihon university
(April, 1997) a postdoctoral research fellow at IIS, University of Tokyo
(June, 1998) a research associate at IIS, University of Tokyo
(April, 2001) a research associate at CST, Nihon University
(April, 2006) an assistant professor at CST, Nihon University
(April, 2011 to 2015) an associate professor at CST, Nihon University
(April, 2015 to present) a professor at CST, Nihon University
(September, 2012 to 2013) an academic visitor at The University of Strathclyde, Glasgow UK

Authors:

Tomoki Ikoma Nihon University
Airi Kuwata Nihon University
Yasuhiro Aida Nihon University
Koichi Masuda Nihon University