Model study on “pendulor” type wave energy device to Utilize ocean wave energy in Sri Lanka

Abstract

Sri Lanka being an island it is inevitable to utilize the ocean wave energy as a sustainable energy source. The device called “Pendulor”, which is invented in Japan and has proven 40-50% of wave energy conversion efficiency at the sea of Muroran, Japan. The low wave energy density oceanic climate of Sri Lanka makes this device more preferred, because of its high energy conversion capability. The device consist a pendulum flap hinged inside a caisson and the caisson is faced to the ocean waves. The economical feasibility of this device depends on the construction cost. The conventional caisson is a straight chamber and this type of a device is infeasible because of the length that causes increase in construction cost. A modified caisson is proposed to shorten the caisson length towards the sea and to increase the frequency bandwidth of operation. Model testing of this modified caisson with a solid friction damper is addressed in this endeavor. Laboratory experiments were conducted with a 1/16 scale model of the proposed caisson. A solid friction damper was used for the model testing and a mathematical model for the device was developed and the parametric modeling was done by using MATLAB. The power conversion efficiency with a modified caisson was discussed in this endeavor.