Experimental Investigation on the Wells Turbine with Tubercle-Twisting Blade for Performance Enhancement on Oscillating Water Column

The Wells turbine is an air turbine in the Oscillating Water Column (OWC) system with lower performance than the Impulse turbine at small diameters.However, the Wells turbine can operate at lower wave heights compared to the Impulse turbine.Therefore, the purpose of this study is to examine the performance improvement of the Wells turbine at low wave heights by modifying the blades to incorporate tubercle twisting.The tubercle is inspired by the excellent maneuverability of the humpback whale flipper, while the twisting of the helical blade improves the turbine performance.The experimental method was conducted in the Wave Chamber of the Energy Design Laboratory at the Sumatra Institute of Technology, with an average wave height of 28.69 cm.The experiment was conducted by comparing the performance results of the Wells and Tubercle-twisting turbines using a kinetic performance approach.The experimental results show that the C p max of the Wells turbine occurs at a flow coefficient ( φ ) of 0.88, with a value of 0.059.In contrast, the tubercle-twisting turbine occurs at φ =1.71, reaching a C p max of 0.394.This means that tubercle twisting can improve the performance of the Wells turbine by up to 567.79% at low wave heights.