Experimento em escala e análise do coeficiente de potência de uma turbina eólica acoplada a um difusor.

Abstract

Horizontal axis wind turbines have a relatively low yield (45%). However, this value can be increased by equipping it with an aerodynamic diffuser. A diffuser is equipment that induces a larger flow of air mass due to a pressure difference that it causes between the turbine inlet and outlet. For this reason, this work aimed at the construction of an aerodynamic diffuser to verify the increase of the efficiency of a wind turbine in scale. For this purpose a 17.5 cm blade rotor with specific tip speed of 7 and NREL S809 aerodynamic profile was used. The diffuser was built with NACA 4412 profiles, with an angle of attack equal to 4 º. The tests were performed at the Laboratory of Aerodynamics and Fluid Mechanics (LAERO) of the Federal University of Ceará (UFC), from which free flow velocity, flow velocity with the rotor in operation, as well as angular velocity and velocity measurements were collected. torque generated by the blades, in order to know the rotor power coefficient curves and the rotor - diffuser set torque and compare them with the rotor curves without the diffuser. There was an increase in the Power Coefficient for three cases of specific velocity (λ = 5.48, λ = 5.87 and λ = 6.84), with a maximum increase of 11.11% to λ = 5.48.