Design and CFD Analysis of the Energy Efficiency of a Point Wave Energy Converter Using Passive Morphing Blades

A wave energy converter features the ability to convert wave energy into the electrical energy required by unmanned devices, and its energy-conversion efficiency is an essential aspect in practical applications. This paper proposes a novel point-absorption wave energy converter with passive morphing blades to meet the demand for improved energy-conversion efficiency. We first introduce its concept and design, with its blades forming their shape by adaptive changes with the direction of the water flow. Next, the three-dimensional geometrical-morphing model, energy-conversion model, and energy-conversion-efficiency model of the wave energy converter were established. Then, the CFD model was built to optimize the design parameters, and the simulation results revealed that the maximum conversion efficiency can be obtained at 90% solidity with 10 blades, a 40–60% load, and 20~25 degrees for the external deflection angle. The simulations also showed that the passive morphing-blade group provides ~40% higher torque and ~60% higher hydraulic efficiency than the flat-blade group.