An Experimental Study of Wave Amplification Inside an Open Caisson for Harnessing Wave Energy

A new concept of wave energy extraction which combines an open caisson and a wave energy converter (WEC) is under development. Harbor resonance inside the caisson provides a possible way to amplify wave energy for WEC's operating in regions of medium wave energy density. In the present paper, we conducted an experimental study on the amplification effect for a cylindrical caisson with an opening. The parameters in the study include the wave incident angle, wave period, and caisson opening angle. Two different caissons were designed for the present study. One is with a pair of wave guides mounted on both edges of caisson opening. The shape is a part of circular cylinder. The other one is without the guides. The experimental results show that the wave inside the caisson can be significantly amplified. The amplification factor, defined as the ratio of wave height inside the caisson to that of the incident wave, can reach up to 2 for some particular wave periods. The effect of the wave guide is also significant.