Buffet Alleviation on Swept and Unswept Wings at High Incidence
| Autor: | Jonathan Morrison, G. A. Flynn, Dennis G. Mabey |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Journal of Aircraft. 38:368-378 |
| ISSN: | 1533-3868 0021-8669 |
| DOI: | 10.2514/2.2771 |
| Popis: | Buffeting measurements have been made on semirigid swept and unswept wings with a GA (W)-1 section, at Reynolds numbers Rec up to 10 6 . Results show that a permeable surface, vented to an otherwise airtight plenum, reducestheseverity ofthebuffetexcitation. Airpassing through theplenum reduces the amplitude of theunsteady separation point. However, the separation is highly three dimensional, producing stall cells and foci of surfacenormal vorticity. Qualitative evidence suggests that the buffet excitation parameter increases rapidly when the size of the stall cell approximately doubles and the projected area of separated e ow adjacent to the wing increases abruptly. The use of a segmented model ensures that the wing is sufe ciently e exible to retain the e rst bendingmoment modeshape. Italso allowsthe position of the permeable surfaceto bemoved to followthemean separation line approximately. Measurements show signie cant attenuation of the buffet excitation parameter, by as much as two-thirds, for optimally aligned permeable surfaces. However, in attached e ow the permeable surfaces increase buffetexcitation,and,whenplacedinaregionoflargefavorablepressuregradientneartheleadingedge,separation occurs farther upstream causing an even larger increase in buffet excitation. |
| Databáze: | OpenAIRE |
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