A geometrical optimization method applied to a heaving point absorber wave energy converter

Abstract

A methodology for the geometrical optimization of wave energy converters (WEC) based on statistical analysis methods and the hydrodynamics of the system in the frequency domain is presented. The optimization process has been applied on a one-body heaving point absorber for a nearshore region of the Rio de Janeiro coast. The sea characteristics have been described using a five-year wave hindcast and are based on a third generation wind wave model WAVEWATCH III. The optimization procedure is performed based on the resultant wave spectrum and joint probability distribution. The optimization process aims at maximizing both WEC absorbed power and absorption bandwidth when providing a natural period close to the predominant wave periods of the sea site. The optimized geometry of the WEC is determined by running a few simulations in the frequency domain and using the design of experiment (DOE) method. The software ANSYS-AQWA is used for the hydrodynamic diffraction analysis, and the DOE method is applied through the Minitab software to determine the optimized geometry. The two primary advantages of this optimization method are the reduced computational time and the possibility of performing parametric analyses for the WEC geometry.