Abstract
Separated flow on a Wells turbine blade causes poor performance of the turbine. Implementing passive flow control techniques, such as leading-edge prism cylinders (LE-PCs), effectively delays flow separation within a system. The prism cylinder alters the angle of attack (AoA) and modifies the boundary layer profile. The shapes of the prism cylinders were square, hexagonal, octagonal, and decagonal. The prism cylinder circumference was fixed at 2% of the chord length (C), and the gap between the PC and the LE was 2.5%C and 3.5%C. The prism cylinder was placed at the blade chord line to maintain the Wells turbine symmetry. For the numerical simulations, the turbine performance parameters are calculated using steady-state Reynolds-averaged Navier–Stokes (RANS) equations along with a k–ω SST turbulence model. Results showed that a gap of 3.5%C of the hexagonal prism cylinder improves the performance and provides a more comprehensive working range of 22.22% and an average torque coefficient of 43%. The prism cylinder modifies vortex strength and kinetic energy of the incoming flow and, finally, manipulates the suction-surface (SS) flow separation and re-energizes the separated flow.