د. عبد الهادي عبد المطلب العبادي2025-03-112025-03-11https://dspace.academy.edu.ly/handle/123456789/1459Engineers always search to develop the performance of wind turbines in order to extract the greatest amount of energy available in the wind, where in a wind turbine wake there are many important aerodynamic factors affecting the behavior and structure of the flow field, from it the formation of tip vortices at the blade tip, where, a tip vortex formed due to the pressure difference between the upper and lower surface of the blade, and causes a variety of performance losses and noise problems for horizontal axis wind tur-bines (HAWT). In this study experimental investigation of the effects of the flaps as a tip device on the performance of the wind turbine model is performed on two models of horizontal axis wind turbines have different numbers of blades(model 1 has 2Blades, and model 2 has 3Blades) at specific blade pitch angles as well as specific speeds by a wind tunnel, each model has a 0.26m diameter of rotor, and profile of its blade is NACA8704. Results of baseline measurements(without flaps) showed that blades number of model affects performance of wind turbine model, where, that the perfor-mance of model which contains three of blades(model 2) best than the performance of model which has two of blades(model 1). After made modifications to model 2 that has the best performance values by adding flaps as a tip device(modified model) the meas-urements with the flaps resulted that performance values of model 2(Cp) increase with flaps. And this indicates that the flaps as a tip device improve the performance of the wind turbine model due to a reduction of tip lossesEngineers always search to develop the performance of wind turbines in order to extract the greatest amount of energy available in the wind, where in a wind turbine wake there are many important aerodynamic factors affecting the behavior and structure of the flow field, from it the formation of tip vortices at the blade tip, where, a tip vortex formed due to the pressure difference between the upper and lower surface of the blade, and causes a variety of performance losses and noise problems for horizontal axis wind tur-bines (HAWT). In this study experimental investigation of the effects of the flaps as a tip device on the performance of the wind turbine model is performed on two models of horizontal axis wind turbines have different numbers of blades(model 1 has 2Blades, and model 2 has 3Blades) at specific blade pitch angles as well as specific speeds by a wind tunnel, each model has a 0.26m diameter of rotor, and profile of its blade is NACA8704. Results of baseline measurements(without flaps) showed that blades number of model affects performance of wind turbine model, where, that the perfor-mance of model which contains three of blades(model 2) best than the performance of model which has two of blades(model 1). After made modifications to model 2 that has the best performance values by adding flaps as a tip device(modified model) the meas-urements with the flaps resulted that performance values of model 2(Cp) increase with flaps. And this indicates that the flaps as a tip device improve the performance of the wind turbine model due to a reduction of tip lossesExperimental Study On Horizontal Axis Wind Turbine Model Performance