The Performance of a Three-blades Fish-ridge Turbine in an Oscillating Water Column System for Low Waves

The turbine power coefficient on the OWC system is determined when the turbine works under compression and suction conditions. The OWC system with VAWT turbines is believed to be suitable for use in low wave areas. In this paper, a design and performance simulation of three-blade of the fish-ridge turbine is applied to the OWC system. The method used is a simulation with CFD to get a profile of the contour of speed and pressure when compression and suction in the chamber. Simulations produce power coefficients, tip speed ratios calculated from wind speed parameters in the chamber, turbine torque, and turbine rotation speed. The results of this study are that there is a difference between airflow velocity and air pressure during compression state or suction state. This difference is due to the airflow in the suction passing through a smaller space than when it is in a compression state. The surface area of the inlet/outlet water is wider than the surface area of the inlet/air outlet. Energy extraction in this OWC system reaches 24.5% at 6.5m/s wind speed, compared to the application of fish-ridge turbines on open systems. The sensitivity of the fish-ridge turbine on the OWC system increased due to two conditions, namely in compression conditions and suction conditions and the presence of small arcs on the turbine blades which facilitate more even distribution of velocity and air pressure.