It is possible to meet the world expanding energy needs in an environmentally sustainable manner by harnessing energy from the ocean. The technical readiness level for ocean energy is still relatively low. A typical wave energy conversion technology is the Oscillating Water Column (OWC) type wave energy converters with axial turbines. The Wells turbine, a bidirectional axial turbine, is often seen in offshore wind stations for its ease of usage and maintenance. Wells turbines can only be used in a limited number of ocean conditions because of their limited working range. The geometric characteristics of a Wells turbine are studied separately from earlier research and then combined to construct a multiparameter modified Wells turbine in Solidworks. This study includes some parameters in this Wells turbine that may postpone the stall, and after the stall, the rate of efficiency and torque degradation is smooth. Guide vanes are used in Wells turbines to optimize the torque characteristics. Optimal endplate and blade sweep/skew combinations are investigated. To further increase the operational turbine range, the Wells turbine casing incorporates a casing grove design. Casing grooves are often utilized in axial multistage compressors to prevent the compressor from choking and increase the output pressure. The groove width and depth describe the Casing groove in the Wells turbine casing in the percentage of the blade chord length. The oscillating water column (OWC) paired with a Wells turbine is a prominent wave energy conversion equipment. In the past, most computational and experimental investigations explored the Wells turbine properties either in the absence of load or some time with a specific load to attain a certain rotational speed. The current study involves designing and testing a modified Wells turbine. The main component of the test setup is a piston-chamber assembly that is responsible for generating a sinusoidal varying airflow inside a duct. The Wells turbine is examined for different stroke lengths and time periods of the piston. The properties of the modified Wells turbine are investigated without load and with different loads on the generator. Under different operational situations, a comprehensive examination of the modified Wells turbine flow velocity varies between 2 to 12 m/s, electrical power output variation between 5 to 35 Watt, and mechanical efficiency between 25-30 %.

Keywords: Wells turbine; OWC; Wave energy; Wells turbine; Experimental analysis.