Constructal Design Applied to an Overtopping Wave Energy Converter Locate on Paraná Coast in Brazil

This research aims a numerical and geometrical investigation about an Overtopping Device Wave Energy Converter (OTD-WEC). Constructal Design method was employed to perform a geometric evaluation of this OTD-WEC submitted to ocean waves with similar characteristics of the coastal region of Paraná State – Pontal do Paraná city in southern Brazil, located 41 km from the coast and 30 m water deep. It was analyzed two different significant wave heights, HS1 = 1.25 m and HS2 = 1.50 m. In each set, it were simulated 10 cases with different ramp angles, totaling 20 numerical simulations. The main goal was to evaluate the influence of the ramp angle on the water mass flow rate entering the reservoir. Therefore, through the Construtal Design, the degree of freedom (DOF) H1/L1 (ratio between the height and length of the ramp) was varied, considering a constant area of the ramp. For the numerical analysis, a two-dimensional computational model was employed using the commercial software Ansys Fluent, which is based on the Finite Volume Method (FVM). The multiphase Volume of Fluid (VOF) model was applied to tackle with the water-air interaction. The results showed that the best geometric configurations happened for those cases with smaller ramp angles. In addition, a reconfiguration of the ramp angles, keeping the area fixed, allowed a significant improvement in the OTD-WEC available power.