Application of passive trailing rdge morphing for aerodynamic enhancement of HAWT blades under low reynolds number conditions

This study investigates the enhancement of the aerodynamic performance and efficiency of horizontal-axis wind turbine (HAWT) blades through passive trailing-edge morphing. The novelty of this work lies in the application of substantial trailing-edge deflection at 50% chord to a NACA 2412 airfoil for HAWT applications. The effects of three deflection angles (+5°, +10°, and +15°) were investigated numerically and experimentally under low-Reynolds-number operating conditions. Numerical analyses, conducted using the k–ε turbulence model and the multiple reference frame (MRF) approach, were complemented by experimental validation using a 350-mm-diameter HAWT prototype in a low-speed wind tunnel. The primary objective was to assess the influence of trailing-edge morphing on the coefficient of power, flow characteristics, and surface pressure distributions. The results show that the coefficient of power generally increases with the tip-speed ratio (TSR) within the optimal operating range before declining at higher TSRs. Importantly, trailing-edge deflection significantly enhanced the coefficient of power across most TSRs, with the +15° deflection consistently yielding the highest performance in both the numerical and experimental analyses. The numerical and experimental coefficient-of-power values agreed within 10%, while the blade with a +15° trailing-edge deflection demonstrated a substantial 46.5% increase in performance relative to the straight blade at a TSR of 6.0. These findings demonstrate that passive trailing-edge morphing is a promising approach for improving the aerodynamic efficiency of small-scale HAWTs, particularly under low-Reynolds-number operating conditions.