Enhancing the performance of Wells turbines with leading-edge external bodies in oscillating water column systems

Conventional Wells turbines used in Oscillating Water Column (OWC) systems face problems like low torque generation and a limited operating range, which reduce their efficiency in wave energy applications. This research investigates the use of an Ellipse Leading-Edge External Body (LEEB) as a passive flow control device to solve these problems and improve turbine performance. Different LEEB designs were analyzed systematically by changing their length, width, height, and position relative to the leading edge of the turbine blade. Geometric modeling was done using SolidWorks, and computational fluid dynamics (CFD) simulations were carried out with ANSYS-CFX. The simulation results revealed that the optimal ellipse LEEB configuration, with a width of 0.04C, a diameter of 0.016C, and a distance of 0.08C from the leading edge, improved the peak torque coefficient by 38 % and extended the operating range by 22.2 % compared to the baseline model. These findings demonstrate the effectiveness of the ellipse LEEB in delaying flow separation, enhancing energy transfer, and expanding the operational efficiency of Wells turbines. This research underscores the potential of LEEB to advance sustainable wave energy technologies and lays a foundation for future implementation in OWC systems.