Efficient Nonlinear Response Determination of an Array of OWC Energy Harvesters

Abstract

Abstract Oscillating Water Columns (OWC) are utilized for producing electrical energy from sea waves by exploiting the oscillation of a water column located under an air chamber for producing an air flow driving an air turbine connected to an electrical generator. The array configuration is considered in several engineering applications, where the OWCs are embedded in coastal infrastructures, such as vertical breakwaters. In this context, the water columns are likely to be placed nearby. Thus, interactions among chambers occur because of wave radiation phenomena. This article describes a nonlinear model governing the dynamics of an OWC array embedded in a vertical breakwater. The differential equations include effects associated with hydrodynamic memory and isentropic thermodynamics, which prohibit the derivation of an exact solution giving the OWC array response. Thus, the article develops approximate solutions determined by relying on the concept of equivalent linearization, which is applied under the assumption of both deterministic, and stochastic excitations. Juxtaposition of the approximate approach results with relevant direct numerical integration data confirm its reliability and efficiency.