Experimental and numerical analysis of the aerodynamic characteristics of flexing wing with active camber design

The flexing/morphing concept is a means of improving wings’ aerodynamic performance. Morphing technology such as the fishbone active camber (FishBAC) design has demonstrated drag reduction of over 30% at moderate angles of attack (AoAs) and 40% at higher AoAs and tail deflections compared to plain flap systems. In the current study, a morphing FishBAC wing model was designed and built for experimental measurements. The rear 25% of the wing portion was made of a flexing element with a maximum deflection of 32°. The measurements were conducted in a subsonic wind tunnel instrumented with a two‐component force–balance system. The FishBAC model was shown to be effective in all tested configurations. It tended to be more aerodynamically effective and efficient at higher AoA and lower flex deflections. An increase in the lift coefficient of up to 25% and drag reduction of up to 37% were observed. The overall aerodynamic efficiency at higher AoAs in terms of glide ratio was up by 50% compared to a plain flap. The experimental measurements and data were complimented by computational fluid dynamic (CFD) simulations, where the aerodynamic characteristics were compared and validated. Overall, the experimental and CFD data compared well in the given range of AoAs and flex angles. However, the CFD data tends to overestimate the lift and drag coefficients at the high end of the AoA range.