Hydrodynamic analysis of a dual-body Wave Energy Converter device with two different Power Take-off configurations

Julio Cesar de Souza Filho

Key information

Authors:

Julio Cesar de Souza Filho (Julio Cesar de Souza Filho)

Supervisors:

Carlos António Pancada Guedes Soares (Carlos Guedes Soares); Kourosh Rezanejad (Kourosh Rezanejad)

Published in

October 8, 2021

Abstract

The aim of the present thesis is to improve of the efficiency of dual body wave energy converters by changing the configuration of the power take-off installed. This is done by optimizing two different configurations (power take-off in between the floater and the submerged body, and power take-off in between submerged body and sea bottom) to be installed in Pico-Azores. The study is considered to be important as a higher efficiency means less cost to generate energy, being this one of the barriers of usage of wave energy converters nowadays. The analyzes begin with the modeling of the bodies of each wave energy converter in NEMOH, that is a software that allows the calculation of the hydrodynamical coefficients of the bodies (floaters and submerged bodies). With all the hydrodynamical coefficients calculated it is possible to create a dynamical model in frequency domain that optimizes/compares the maximum efficiency of the configurations. After that, using previous researches that carried out similar calculations, the model is validated by entering all the input parameters equal to the ones in the researches and comparing the outputs (hydrodynamical coefficients, absorbed power, efficiency, and also sea spectrum creation). All outputs are found to be similar and so the model is considered validated. Finally, the presentation of the results is done. The comparison is made for three different combinations of bodies (cylinder-sphere, cylinder-cylinder, and sphere-sphere, for the floater and submerged body respectively). The second configuration is considered more efficient, having an average improvement in the efficiency of 10.85%.