Effect of column slope on the performance of an Oscillating Water Column (OWC) devices

Single chamber oscillating water column (SCOWC) has been designed in various forms until it changes to a double chamber oscillating water column (DCOWC). This study investigates the effect of varied water column’s slope angle in SCOWC and DCOWC on the efficiency of wave energy absorption. Achieving this objective, the device developed with three column slopes, namely 90 (vertical column), 60, and 30. The investigation applied for various wave periods to check the effect of resonance on the column slope variation. A non-dimensional factor kh is introduced to evaluate energy absorption of varied depth and wave parameters in a graph. The results show DCOWC design only effective for a vertical column (90), however, the efficiency of an OWC increases with the lower column slope. Using DCOWC improves the efficiency of 90 by 5.9% and none for 60 and 30. The maximum efficiency is 22.4% at h = 24cm with T = 1.3s; 31.3% at h = 24cm with T = 2.4s; and 40.6% at h = 22cm with T = 2.4s for 90, 60, and 30 columns.