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NASA-TP-1020
Theoretical parametric study of the relative advantages of winglets and wing-tip extensions
Year: 1977
Abstract: It was found that for identical increases in bending moment, a winglet provides a greater gain in induced efficiency than a tip extension. Winglet toe-in angle allows design trades between efficiency and root moment. A winglet showed the greatest benefit when the wing loads were heavy near the tip. Washout diminished the benefit of either tip modification, and the gain in induced efficiency became a function of lift coefficient; heavy wing loadings obtained the greatest benefit from a winglet, and low speed performance was enhanced even more than cruise performance. Both induced efficiency and bending moment increased with winglet length and outward cant. The benefit of a winglet relative to a tip extension was greatest for a nearly vertical winglet. Root bending moment was proportional to the minimum weight of bending material required in the wing; it is a valid index of the impact of tip modifications on a new wing design.
Subject: AERODYNAMIC CHARACTERISTICS
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T15:43:26Z | |
| date available | 2017-09-04T15:43:26Z | |
| date copyright | 09/01/1977 | |
| date issued | 1977 | |
| identifier other | PMBBFEAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/45699 | |
| description abstract | It was found that for identical increases in bending moment, a winglet provides a greater gain in induced efficiency than a tip extension. Winglet toe-in angle allows design trades between efficiency and root moment. A winglet showed the greatest benefit when the wing loads were heavy near the tip. Washout diminished the benefit of either tip modification, and the gain in induced efficiency became a function of lift coefficient; heavy wing loadings obtained the greatest benefit from a winglet, and low speed performance was enhanced even more than cruise performance. Both induced efficiency and bending moment increased with winglet length and outward cant. The benefit of a winglet relative to a tip extension was greatest for a nearly vertical winglet. Root bending moment was proportional to the minimum weight of bending material required in the wing; it is a valid index of the impact of tip modifications on a new wing design. | |
| language | English | |
| title | NASA-TP-1020 | num |
| title | Theoretical parametric study of the relative advantages of winglets and wing-tip extensions | en |
| type | standard | |
| page | 80 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1977 | |
| contenttype | fulltext | |
| subject keywords | AERODYNAMIC CHARACTERISTICS | |
| subject keywords | BENDING MOMENTS | |
| subject keywords | EXTENSIONS | |
| subject keywords | WING LOADING | |
| subject keywords | WING ROOTS | |
| subject keywords | WING TIPS | |
| subject keywords | WINGLETS |