Experimental study on a bottom corner of the floating WEC

The study is investigating the effects of various back bottom corner geometries of the Backward Bent Duct Buoy floating oscillating water column at different wave height conditions. Three BBDB with different geometries of the back bottom corner, namely curved, square, and inclined were used. The 3-dimensional wave basin was used to generate the regular wave spectrum with wave heights of 0.05 m–0.15 m and wave periods of 1 s–5 s. It demonstrated the characteristics inside the air column of each BBDB were significantly influenced by the back bottom corner geometry. The results showed that the curved bottom corner produced the highest water elevation, water column chamber pressure, and outlet air flow rate. This observation was due to the curved geometry that reduced the viscous energy loss from the body surface and water. Moreover, it was found that the curved bottom corner produced the higher primary conversion efficiency compared to the square and inclined bottom corner. Despite the characteristics inside air column, it was found that the resonance frequency contributed to the maximum value of the primary conversion efficiency regardless of the various geometries of the back bottom corner. •The curved reduce the viscous energy loss and improve the performance of the wave energy converter.•The resonance frequency contribute to the primary conversion efficiency regardless geometry of the corner.•The water level inside the water column is significantly influenced by the corner geometry.