Wing extensions for improving climb performance

Recent wind tunnel studies have shown that significant improvements in wing efficiency and climb performance can be achieved using wing extensions having sharp edges and unmodified upper airfoil contours. Based on tests of six configurations, a simple tip shape provided the best wing efficiency at high lift conditions without penalty during cruise conditions. The best configuration tested exhibited more than 20 percent improvement in the maximum rate of climb, plus a reduction in stall speed and a slight improvement in cruise performance over a baseline tip with a round edge. In addition to measurements that were used to determine performance, flow visualization studies provided insight into reasons for improved wing efficiency. Tests were conducted using a high performance general aviation aircraft model with a tapered, cantilevered wing.