Abstract: This study develops a novel Backward Bent Duct Buoy (BBDB) Oscillating Water Column (OWC) wave energy conversion device with a plate to improve Capture Width Ratio (CWR) and widen response frequency band width. To examine its performance and the effect of the plate, this study tests its physical model in a wave tank and calculate its pneumatic energy conversion through air pressure measurement and using a formula of the flow rate-air pressure relationship. Its behaviors are examined for the conditions of various orifice area ratios, mooring locations, and drafts; and compared with those of a conventional BBDB-OWC converter under a set of wave conditions. The results reveal that this device has the maximum CWR 13.8% larger and its wave frequency range of CWR > 70.0% is widened by 21.9%. Thus, the plate helps improve CWR and response frequency band width.

Key words: wave energy, Backward Bent Duct Buoy (BBDB), Capture Width Ratio (CWR), response frequency band width, physical model test, plate