Experimental investigation of a novel OWC wave energy converter

Wave energy, one of the safest and currently growing forms of renewable energy, requires the development of the appropriate wave energy converters (WECs). This study presents a recently patented WEC; and proves the feasibility of this concept using a series of experiments. To achieve this, two rectangular chambers of an oscillating water column (OWC) system were arranged in series, and the wave with a propagation direction that forms a relatively small angle of 30 degrees with the front walls was referred to as obliquely incident wave. The effects of the wave amplitude, front wall draughts, and opening ratios were investigated in relation to the overall hydrodynamic performance and the respective performances of the two sub-chambers. It was found that the overall efficiency of the system was greatly reduced as the front wall draught in the high-frequency zone increased. Furthermore, the opening ratios of the individual chambers significantly affected the overall hydrodynamic performance for all frequency bandwidths under obliquely incident waves, and the optimal efficiency achieved at the opening ratio of epsilon = 1%. The rear chamber is inferior to the front chamber for most of the wave frequencies.