Numerical modelling of a wave energy converter based on the wave climate around the Saint Martins island of Bangladesh

Abstract

Saint Martin′s Island is the only coral island and one of the well-known tourist spots in Bangladesh. Because of its geographic location, electricity cannot be supplied from the mainland through the electricity grid. Diesel generators and solar power are the only means of electricity generation presently available there. Surrounded by the sea, Saint Martin′s Island has the ideal conditions for wave energy extraction. The purpose of the study is to assess and optimize the performance of a heaving-point-absorber-wave-energy-converter in light of the existing wave climate around the island. The power generation performance of a cylindrical buoy shape has been tested for a variety of diameters and drafts. The mass properties of the selected design have been determined using simple structural analysis, and the hydrodynamic coefficients have been calculated through modelling and simulation in frequency-domain. Using the hydrodynamic coefficients data obtained from frequency-domain analysis, the response as well as power output of the system have been estimated using time-domain analysis with linear power take-off system. Comparing the power performance of different draft diameter combinations of cylindrical buoy, the best design with maximum power output per unit buoy weight have been selected. Moreover, two other buoy shapes are tested, the values of surface area and volume obtained from optimal cylindrical configurations are used to generate new buoy profiles. Finally, comparing the results of power performance simulations, a discussion on the behaviors of different buoy shapes in different months have been presented and most suitable buoy shape for the intended energy deployment site have been proposed. Moreover, the key areas that requires further investigation have been identified and discussed.