Opening orifice optimization for floating oscillating water column

Ocean wave energy is one of the promising sustainable energies sourcing from the movement ofthe surface ocean waves producing electrical energy. This eliminates the need for fossil fuels such as diesel for power generation at remote islands, which consequently reduces the carbon footprint and the logistic costs of diesel supplies. The Power Take Off (PTO) system is the system designed to convert the oscillation motion created by the ocean waves and turn into electrical power. One of the most common PTO systems in use is the pneumatic turbine system. The air that leaves the air column inside the wave energy converter device (WEC) will pass through the orifice before entering the turbine system. Hence, the design of the orifice is essential to ensure the highest pneumatic efficiency is obtained. This study will investigate the different sizes of WEC orifice with an elbow and straight PTO connection to compare the output of the WEC in terms of primary efficiency. Several orifices were designed. fabricated, and tested experimentally on a WEC using a wavemaker. The output in terms ofWEC performance was measured using a set ofsensors and a data acquisition system. From the results, it was found that the smallest orifice diameter (ratio 0.5%) with a straight connectionproducedthe highest efficiencyof up to 0.29 compared to other orifice sizes with elbow connection. The outcome of this study is to achieve the optimized design of the orifice to produce the highest primary conversion efficiency for the WEC device.