Analyses of Aerodynamic Characteristics and Boundary Layer Features of Airfoils at Low Reynolds Numbers and Moderate Turbulence Intensities

Research studies on low Reynolds number are continuously gaining technical interest aiming to contribute to the advancement of small aerial vehicles and wind turbines. Despite this, there are issues though concerning the sensitivity of the boundary layer on the airfoil surface due to their low-speed operating condition and the unstable environment where they are situated in. In order to enhance the performance of these machines, aerodynamic analysis of the airfoils employed for these kinds of applications needs to be essentially conducted. Therefore, this study aims to investigate the aerodynamic characteristics of several airfoils suitable for small-scale horizontal-axis wind turbines. Numerical results show that the effects of Reynolds number and turbulence intensity are somewhat similar in terms of lift-to-drag ratio and chordwise behavior of separation bubbles. Likewise, different structures exhibited by the flow on the airfoil upper surface were captured as functions of angle of attack, Reynolds number and turbulence intensity.