Abstract
The REWEC3 (Resonant Wave Energy Converter – realization 3) is a fixed oscillating water column (OWC) wave energy converter (WEC) based on a U-shaped collector (for this reason namely also U-OWC) aimed to be incorporated in breakwaters. The device is composed by a chamber containing a water column in its lower part and an air pocket in its upper part. The air pocket is connected to the atmosphere via a duct hosting a self-rectifying air turbine. In addition, a REWEC3 includes a vertical U-shaped duct for connecting the water column to the open sea. The working principle of the system is quite simple: by the action of the incident waves, the water inside the U-shaped duct is subject to a reciprocating motion, which induces alternately a compression and an expansion of the air pocket. The pressure difference between the air pocket and the atmosphere is used to drive an air turbine coupled to an off-the-shelf electrical generator connected to the grid.
The main feature of the REWEC3 is the possibility of tuning the natural period of the water column in order to match a desired wave period through the size of the U-duct.
This paper aims to provide an optimized configuration of the U-OWC pneumatic chambers in order to maximize the air power available to a possible PTO for the wave energy conversion. For this purpose, two different REWEC3 configurations are analysed: A) with independent cells, that is the REWEC3/3 or U-OWC/3; B) with adjacent connecting cells, that is the REWEC3/2 or U-OWC/2. Finally, a critical analysis of the performances in both configurations will be presented.
