Experimental Results of Winglets on First, Second, and Third Generation Jet Transports

摘要

This paper presents the results of wind-tunnel investigations of winglets on four jet transport configurations. Performance and wing-root bending moment data are given. Additionally, detailed aerodynamic characteristics are pre¬sented at the design condition and also at several off-design conditions for one configuration.nResults of the investigations indicate that winglets improve the cruise lift-to-drag ratio between 4 and 8 percent. The data also show that the ratios of relative aerodynamic gain to relative structural weight penalty for winglets are 1.5 to 2.5 times the ratios for wing-tip extensions. The comprehensive investigation of the effects of winglets has indicated that winglets produce no adverse effects on buffet onset, lateral-directional stability, and aileron con¬trol effectiveness. A winglet flight research and demonstration program has been initiated and results are expected to be available near the end of 1979.