Numerical Simulation of the Flow Around Wind Turbines using the Im- mersed Boundary Method

Resumo

The aerodynamics study in wind turbines by computational fluid dynamics (CFD) techniques is funda-
mental since these tools help improve the performance of wind turbines and the choice of design of the rotor blades

more efficient. Thus, we perform a computational simulation to (i) obtain the lift and drag coefficients of the s809
airfoil (ii) obtain the torque and power of the NREL PHASE VI wind turbine. The wind turbine simulations were
performed with a fixed 3-degree blade pitch angle and constant 72 rpm rotational speed. The inlet velocity was
equal to 7 m/s, 10 m/s, 15 m/s, and 20 m/s. The angle of attack of the airfoil was varied from 0 to 20 degrees to

obtain the lift and drag coefficients curves. The closure turbulence models Unsteady Reynolds-Averaged Navier-
Stokes (URANS) were used in both cases. All of the implementations and simulations were developed using the

in-house software MFSIM (Multiphysics Simulator). The cartesian-structured block mesh was used to model the

fluid dynamics, and the immersed boundary methodology was necessary to model the aerodynamics bodies. Fur-
thermore, using an adaptive grid is a powerful way to save mesh refinement and, therefore, save processing time.

Finally, the aerodynamic results showed a good accord with the reference’s data, being the measurements made in

the NASA AMES wind tunnel for the wind turbine. Therefore, the immersed boundary methodology and adapta-
tive mesh refinement employed in this work proved to be promising computational tools to simulate complex and

moving bodies.