Studying the drag of a triangular wind turbine blade for low wind velocities

This paper is devoted to the development of an experimental model of a wind turbine with a dynamically changing shape of the blade surface, as well as to the determination and calculation of the drag force value. The article considers characteristics of the wind turbine experimental model. The scheme of the wind turbine blade operation was considered. The drag force was determined. The article presents plots of the drag force for a sail blade of the wind turbine model as a function of the air flow velocity and wind flow angle of attack, as well as the drag coefficient of a sail blade of the wind turbine model as a function of the Reynolds number and dimensionless angle of attack. The advantage of sailing wind engines is that they can generate electrical energy in a light wind. A wind flow with a speed of 3–5 m/s is sufficient for the sail type wind turbine produces electricity while blade screw type wind engines stand immovably in such conditions. The authors of this work have been developed a sailing type wind turbine with triangular blades. The novelty of the work is the use of wind turbine blades with dynamically changeable shapes of surfaces as power elements of wind turbine blades. They are made in the form of a triangular flexible sail with a free end.