“…A lot of research activity was also conducted on the turbine blade modifications and passive flow control techniques, including the slotted airfoil [38,39], a slotted deflective flap at the trailing edge [40,41], the airfoil with different trapped vortex cavities layouts [42,43], dimple designs and configurations [44,45], leading-edge airfoil-slat [46], and the Gurney flaps [47,48] in order to delay flow separation across the turbine blades and enhance their performance. The results showed that blade modifications could delay stall and enhance turbine power coefficient by around 18-28%.…”