Investigation into the Effects of Flap End Modifications on the Performance of a Wing with a Single Slotted Flap

摘要

Aerodynamic balance measurements were employed with probe wake traverses, tuft grid pictures, wool tuft probe investigations, and surface oil film tests to study the possible aerodynamic improvements available by the addition of flap end devices to a wing with a single slotted flap. Flat end plates, winglet style flaplets, flap extensions, and variable span slotted flaps were tested at a constant dynamic pressure of 550 N/m sq (corresponding to a Reynolds number of 600,000 and a tunnel speed of 30 m/sec). To simulate take off conditions the flow visualization was performed at a wing incidence of 8 deg with a flap angle of 19 deg. Balance measurements were taken over a complete incidence range of 0 to 20 deg. The most effective modification, based on an A340 Airbus winglet, improves lift/drag ratio (used as a measure of aerodynamic efficiency) by 2.4 percent at an incidence of 10 deg.