Numerical Study on Optimization of the Float in a Shoreline Wave Energy Converter

Abstract

Peng, W.; Fan, Y., and Zhang, J., 2018. Numerical study on optimization of the float in a shoreline wave energy converter.. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1296–1300. Coconut Creek (Florida), ISSN 0749-0208.In this paper, the hydrodynamic performance of the float in a shoreline wave energy converter is investigated under regular waves. A numerical model is built based on the Navier-Stokes solver coupled with immersed boundary method, volume of fluid method and the mechanics model of float. Making use of the laboratory measurements, the numerical model has been proved to be a reliable tool in reproducing wave deformations and the dynamics of the float. Then, the model is employed to test the sensibility of float performance to changes in some variables under various waves: spacing between breakwater and float, length of float. From numerical estimations, it can be concluded that the nondimensional motion amplitude of float will decrease with the increasing float length or spacing between breakwater and float. With different loads, the dynamic of float shows different variation trend against the length of float, which implies further investigations may be needed in the future on the effect of power take-off damping load. Last but not the least, the interactions between water waves and two types of floats (rectangle and convex) are simulated and discussed. With the help of snapshots of water particle velocity field and the water surface profile from numerical calculation, the flow pattern and external forces from the fluid field acting on the float can be estimated. Then, the motion amplitudes of floats are computed and compared, and the convex floats are proved to capture more power than the rectangular ones.