Study the Effect of Winglet Height Length on the Aerodynamic Performance of Horizontal Axis Wind Turbines Using Computational Investigation

Tip vortices are one of the most critical phenomena facing rotary wings such as propellers and wind turbine blades lead to changes in aerodynamic parameters blades. The winglet (WL) device is considered significant passive flow control devices. It used diminish strength at blade tip, enhance characteristics rotor blades, thereby increase overall efficiency. main objective this research improve turbines by adding a tip. An optimum profile was taken build geometry. has three with radius 0.36 m, NACA4418 airfoil sections were profile. computational domain created ANSYS software, model validated for spalart-allmaras k-ω SST turbulence models experimental measurements. solved shapes without tip winglets. Various height lengths per (WHLR) 0.008, 0.02, 0.04, 0.05, 0.06, 0.07, 0.08 studied 90-degree cant-angle constant design speed ratio 4.92. Generally, results illustrate that performance improved using winglet. lift-to-drag coefficient (CL/CD) power (Cp) increasing WHLR until they reach highest improvement value, then start decrease gradually. about 0.042, percentage related 11.6% 6.9%, respectively, an thrust force 14.8%. This mainly caused decreasing vortex near region improving stall behaviors.