Modelagem computacional de escoamentos turbulentos em turbinas eólicas utilizando fronteira imersa e refinamento adaptativo da malha

Abstract

The experiments made in the wind tunnel by NREL using (i) wind rotor profile s809 model and (ii) wind turbine are reproduced computationally in the present work with the objectives of (i) performing a graphical survey of the coefficient lift and drag as a function of the angle of attack and (ii) obtain the low-speed shaft torque and mechanical power as a function of wind speed and analyze the wind velocity profiles in the wake zone using computational probes. The dynamic refinement mesh was used to reduce the computational cost, and the immersed body methodology was employed to represent the solid body immersed in the flow. All the simulations were perform using the in-house software MFSIM. The turbulence closure models employed were the standard k − e and Spalart-Allmaras. In general, the aerodynamic results to the airfoil showed a good accord with the reference’s data. For the wind turbine, the aerodynamic results for the torque and hence mechanical power were satisfactory from U = 10m/s, in U = 7m/s both models diverged from the experimental test. For the computational probes, the results indicated that in the first probes downstream the wind turbine and in the aerodynamic region of the wind rotor closer to the blade root were the locals where the velocities deficits were more intense for both turbulence closure models.