Design of a Wave Generation System Using an Oscillating Paddle-Type Device Anchored to Fixed Structures on the Coast

Abstract

Wave energy, a form of renewable energy, is derived from the movement of sea waves. Wave energy generation devices are technologies designed to harness this resource and convert it into electricity. These devices are classified based on their location, size, wave direction, and operating principle. This work presents the design of an oscillating device for harnessing wave energy. For this purpose, computational fluid dynamics and response surface methodology were employed to evaluate the influence of the percentage of the blade height submerged below the water surface (X1) and the distance from the device to the breakwater in terms of the percentage of the wave length (X2). The response variable studied was the hydrodynamic efficiency (η) of the device. Transient fluid dynamic simulations were carried out using Ansys Fluent software 2023 R1, with input conditions based on a wave spectrum characteristic of the Colombian Pacific Ocean. Analysis of variance determined that both factors and their interaction have significant effects on the response variable. Using the obtained regression model, the optimal point of the system was determined. Numerical results showed that the maximum η of the system was achieved when the device was submerged at 75% of its height and was positioned 10% of the wave length away from the vertical breakwater. Under this configuration, η was 64.8%. Experimental validations of the optimal configuration were conducted in a wave channel, resulting in a η of 45%. The difference in efficiencies can be attributed to mechanical losses in the power take-off system, which were not considered during the numerical simulations.