Numerical simulation of the overtopping-ramp design of a multistage overtopping wave energy breakwater hybrid device

Abstract

One type of wave energy converter is based on the overtopping concept. An example of such device is the multi-reservoir Sea Slot-Cone Generator (SSG) which is based on a simple flat breakwater ramp design. Although it is capable of functioning as both a wave-breaker and wave energy harvester, the SSG still suffers from low performance with 38 percent hydraulic efficiency. This paper presents a numerical study to further improve the performance. The present research work considers the use of convex, concave, V-shape and bridge V-shapes front ramp designs. The overtopping phenomena were simulated using Computational Fluid Dynamic (CFD) software known as Flow3D. The results are presented in the form of mean overtopping discharge and expected power output for each of the three reservoirs. At the end of the study, the final results showed that the highest potential power output is given by the V-Shapes design with 67 percent (56.9 kW) improvement compared to current existing SSG device, which recorded (34.1 kW) at the wave height of 2.80 meters and a wave period of 9.3 seconds.