Turbulence topology behind different sections of the wind turbine blade

Abstract

This work aimed to investigate the turbulence characteristics behind different parts of the wind turbine blade. Airfoils S807, S813, S817, and S803, which characterize the shape of the blade at different lengths, were selected for estimation. During the experiment, the chord-based Reynolds number was 2.6×105, while the angle of attack was zero. Measuring crosssections were placed behind the trailing edge at x·c-1≈0.2, 0.4 and 1.0. For the determination flow topology, we used a Hotwire anemometry with a split fiber probe 55R55 and a miniature X-wire probe 55P64. The obtained data allowed us to determine and compare the evolution of the wake behind different types of airfoils in streamwise and spanwise directions. Thus, the largest and smallest velocity deficit located behind S817 and S803 airfoils, respectively. This trend is also evident in the Normalized Reynolds shear stress distributions. Finally, we determined the spectrum and calculated the Integral length scale, the Taylor and Kolmogorov microscale of turbulent flow. According to the results, profile S817 contributes to the formation of a flow with a large scale of turbulence, while the S803 is contrary.