PASSIVE, ACTIVE, AND ADAPTATIVE SYSTEMS FOR WING VORTEX DRAG REDUCTION

摘要

A group of experimental studies were conducted to investigate the effects of different wing tip devices and systems on the reduction of induced drag. Fixed or passive devices, active systems as well as adaptive systems were analyzed in wind tunnel tests. The experiments were conducted in three stages: 1) an analysis of the effect of delta tip, winglet, and "Hoemer" devices, concerning the aerodynamic characteristics of an agricultural airplane wing; 2) an analysis of the effect of wing tip blowing on vortex drag through a novel system composed of three vectorable Coanda jets; and 3) an analysis of the aerodynamic characteristics of adaptive multi-winglets. Results showed that it is possible to achieve optimum aerodynamic performance for each wing tip system when the mission is precisely defined.