Numerical Fluid-Structure Interaction Analysis of a Wells Turbine With Flexible Blades

Direct energy conversion from ocean waves requires some method of rectifying the oscillatory motion to produce a unidirectional output. The Wells turbine accomplishes this with horizontally mounted symmetric blades, which produce a net torque output when combined with an oscillating water column. Previous studies have been conducted, which investigate the effects of blade profile, turbine solidity, stator tip gap clearance, and a number of guide vane designs intended to improve performance. Both experimental and computational methods have been employed, with computational models typically relying on commercially available computational fluid dynamics (CFD) code and assuming steady-state flow conditions. In this work, the open-source codefoam-extendis used to study the transient behavior of a Wells turbine, with both a standard rigid blade and a blade with a flexible trailing edge. A validated model is established, and the effects of various Young's Moduli are tested and their flow fields analyzed. Significant performance gains are realized, with a nearly 17% increase in output torque in some cases.