Aerodynamic Analysis of a 3D Small Wind Turbine Blade Using NACA 63415 Aerofoil with MRF

Abstract

The flow characteristics over a small wind turbine blade with NACA 63415 aerofoil is analyzed using computational fluid dynamics (CFD). In this analysis, aerodynamic effectiveness over a symmetrical 3D blade is studied experimentally in a low speed wind tunnel. The pressure on the aerofoil surface with chord length of 150 mm was distributed, lift and drag forces were measured at −2, 0, 5, 10, and 15° angle of attacks (AOA) and mean velocity profiles were obtained over the surface. The blade in moving reference frame (MRF) approach is used to verify the pressure and velocity contours on the fan when moving at an optimum speed of 650 rpm. The blade is modelled in CATIA V5R20 and analysis is carried using CFX, ANSYS, and FLUENT 18.1 softwares. It is found that the maximum aerodynamic efficiency (\(C_{l}\)/\(C_{d}\)) is achieved at 5° of angle of attack and it can be considered the safe angle of attack. At this angle, the MRF approach is also carried out and the results showed that the better torque of 14.2 N-m can be obtained at 650 rpm speed. It is also observed that the critical angle of attack lies in between 0° to 10°. If this critical angle value changes from this range, it is resulting in a substanitial decrease of lift.