Experimental analysis of the aerodynamic characteristics adaptive of multi-winglets

Abstract
The aim of this research is to study the potential use of adaptive multi-winglets for the reduction of induced drag through variations of winglet cant angles. Different studies have shown that the flow around and over the wing tip can be redirected using small aerodynamic surfaces, thereby reducing the induced drag. The model tested is composed of a rectangular wing using an NACA 653-018 profile with three winglets called ‘tip-sails,’ which are small wings without sweep along the 25 per cent chord line. The tests were made at a Reynolds number of 350 000. The results are analysed in terms of lift and drag. Results show that it is possible to find the best configuration of the three winglets to obtain the optimum aerodynamic performance for each flow regime in climb and cruise.