Comparação de geometrias de hélices para geração de energia eólica: experimento de bancada e simulação

Abstract

The expansion of the sustainable energy sector demands the development of accessible and efficient technologies for microgeneration. This work presents a comparative performance analysis between three-bladed and four-bladed wind propellers, based on the E205 aerodynamic profile, using a hybrid methodology that integrates computational simulation and physical experimentation. Simulations were performed using OpenFOAM v9 software, employing the Finite Volume Method (FVM), the RANS k − ε turbulence model, and the Arbitrary Mesh Interface (AMI) technique to reproduce rotor behavior in a virtual wind tunnel. Experimentally, PLA prototypes were manufactured via 3D printing and tested on an instrumented bench, where angular velocity was measured by a non-intrusive computer vision system. Results showed that the four-bladed geometry exhibited superior performance, achieving a higher steady-state rotation (25.52 rad/s versus 23.64 rad/s) and a higher power coefficient (Cp) under the applied test conditions. The comparison between models revealed an expected quantitative discrepancy between the simulated gross mechanical power (≈ 0.4 W) and the measured useful electrical power (≈ 0.003 W), evidencing that electromechanical conversion losses are the limiting factor in microturbines, rather than the aerodynamic design. It is concluded that the proposed methodology successfully confirms that the four-bladed configuration is more efficient than the three-bladed one for the conducted experiment.