EXPERIMENTAL EVALUATION OF THE AERODYNAMIC PERFORMANCE OF TURBINES SMALL WIND CONFECTIONED IN PROTOTYPING 3D
Saulo de Oliveira Garré1; Adriane Prisco Petry1; Alexandre Vagtinski de Paula1; José Leandro Rosales Luz1; Tanit Daniel Jodar Vecina1
1 Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Engenharia Mecânica
doi:10.20906/CPS/COB-2015-1703
Resumo
This paper presents the experimental evaluation in wind tunnel of two small wind turbines features five blades. Therefore, using 3D prototyping, two models were built on a reduced scale, which were first evaluated using Optimal Blade Betz and Optimal Blade Betz Modified. Prior to evaluating the distribution machine at speeds determined in the tunnel cross-section with the aid of a Pitot tube. With the known tunnel velocity profile, determines the static torque of the prototype with the use of a digital torquimeter coupled to the machine axis, which recorded all the readings for the speed range of 1 m/s to 10 m/s. Also with the torquimeter evaluates the influence of the angular position of the blades in the measured torque. Therefore, it is mobile designed in the hub, allowing vary their angle in the outflow, thereby changing the angle of attack and therefore the torque produced. Employed a photo tachometer for measuring the rotation of the model in free spin. With the data, determines the static torque curve and RPM curve as a function of incident speed. Through experimental determination of the incident velocity profile and the velocity profile in the aerodynamic wake of each turbine is evaluated the variation of the amount of movement of the flow and determined the power extracted by the rotor in free rotation. This study aims to contribute to the design of a real wind turbine informing the aerodynamic characteristics of the equipment shall be constructed with this layout. With the data analyzed to make a prediction for the prototype power curves. The experimental results demonstrate torque and power good approximation to the results obtained by evaluation by analytical element of the paddle method. The turbine constructed with Optimal Betz Blades presented static torque 17,8% higher than constructed with the Modified Blades and extracted 22% more power air outflow.
Palavras-chave: Small wind turbine; Aerodynamic tunnel; Wind energy; Prototyping 3D