We present analysis of a wave energy device that consists of a bottom-pivoted array of vertically-oriented cylinders. The device is studied in moderate water depth and is comprised of three cylinders of equal size and spacing. A limited parametric study is presented to assess the influence of important features of the array on the fluid structure interaction and resulting power output. The pitch motion of the array is investigated via a linear frequency domain model based on the linearised relative velocity Morison's equation. Hydrodynamic coefficients are provided by solving the diffraction and radiation problem around a finite array. Viscous contributions to the coefficients are provided by empirical results from literature. It is shown that a transverse array of moderately sized cylindrical elements experiences an increase in performance as wave frequency is increased. This occurs because the entire structure behaves as a grouping of point absorbers rather than a single large body which allows the structure to avoid a reduction in the forcing function due to diffraction.
Proposed installations of wave energy devices can be categorised according to proximity to land as either: shoreline, nearshore or offshore. The arrays investigated here will reside in the nearshore, defined here as approximately 25 meters in depth and less than 2km from land. This is a relatively attractive option for wave energy conversion due to higher wave energy and lower environmental impact compared to shore line systems and shorter cabling distances relative to offshore installations. In this paper we will investigate a closely spaced array of vertical cylinders that join at the sea-floor to a common power PTO (Power Take-Off) mechanism. The cylinders are restricted to oscillate in pitch mode of motion and are reacted against the PTO mechanism affixed to the sea-floor.