Performance of a Near Shore Oscillating Wave Surge Converter With Variable Flap Configurations in Various Sea Conditions

Abstract Oscillating Wave Surge Converters (OWSCs) are designed to enter survival mode during extreme wave conditions where they forego the opportunity to extract energy to preserve structural integrity. While this is a good tradeoff, it is important that OWSC technology progresses to a point where energy is constantly extracted as long as waves are present. This work addresses the need for an OWSC that can extract wave energy in a wide range of sea conditions while minimizing structural overloading by regulating the fluid-structure interaction. The OWSC being studied here was conceptually designed and patented by researchers at NREL. It consists of a flap face that resembles household blinds, where the flaps can be opened or closed to accommodate the sea conditions. The performance of this variable geometry OWSC in various, shallow wave states was studied in two numerical modeling programs. Of particular interest were the flap’s hydrodynamic coefficients and potential power generation at a specific reference site. This configuration was predicted to mitigate wave forces by allowing some of the wave energy to pass through the device, thus preserving its structural integrity.