SINGLE VERSUS MULTIPLE WINGLETS: NUMERICAL AND EXPERIMENTAL INVESTIGATION

摘要

The main goal of the proposed paper is the numerical and experimental investigation of multiple winglets influence on the reduction of induced drag. This results in the improvement of climbing performances of a motorglider or hang-glider. In a precedent work [1] a set of multiple winglets, very similar to the bird tip feathers called remiges, were designed and optimized for the hang-glider belonging to Angelo D'Arrigo, a world champion hang-glider pilot and record holder. The research aims was to optimize the CL~(1,5)/CD parameter since this is directly proportional to the sink rate. In this work the effects of the multiple winglets, set on an elliptical wing and tested in a wind tunnel, are compared to the effects of three different single 'classical' winglets that were designed using a panel method code and were also tested in the same wind tunnel in order to compare their span efficiency to the one of the multiple winglets.