Dietz, G. (2005) Passive Shock Control Concept for Drag Reduction in Transonic Flow. Journal of Aircraft, Vol. 42 (No. 3), Seiten 794-798.
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Kurzfassung
The operating principle of a novel passive shock control concept for drag reduction on swept wings called D-Strips is introduced, and results of a first experimental proof of concept are presented. Wind-tunnel experiments are conducted at transonic airspeeds using an airfoil VC-Opt (9.2% relative thickness) with forced boundary-layer transition. Schlieren pictures confirm the operating principle. Wake measurements demonstrate that, locally, in the wake of D-Strips the total drag increases. However, more globally, at spanwise locations away from these positions the total drag is measurably reduced if a sufficiently strong shockwave is present above the wing-suction-side surface. In contrast to passive control by ventilation, outside of the wake of the D-Strips a wave and viscous drag reduction and observed. Furthermore, the maximum lift tends to be increased by D-Strips suggesting that the buffet-onset limit is delayed. An application of D-Strips to a swept wing at cruise conditions can yield net aircraft drag reduction because the drag rise is limited to the D-Strips and its wake, but the shock-weakening effect and the drag reduction are distributed in the wide-splayed characteristics upstream of the shock front. The effectiveness of D-Strips is less sensitive to the location of the shock wave than control concepts like two-dimensional bumps, which are only effective at the design conditions. Another application of D-Strips that can be considered is the regions with a distinct shock, for example, between engines or in the wing-root region or at the inboard engine. However, there is a need for further investigations in order to optimize D-Strips and to quantify their impact on aircraft performance. Recent experimental results indicate that airscoop-type configurations might perform better as D-Strips than Velcro-type strips. Because D-Strips are easy to apply on existing wings, an application of D-Strips for retrofit is possible.
elib-URL des Eintrags: | https://elib.dlr.de/14547/ | ||||
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Dokumentart: | Zeitschriftenbeitrag | ||||
Zusätzliche Informationen: | LIDO-Berichtsjahr=2005, | ||||
Titel: | Passive Shock Control Concept for Drag Reduction in Transonic Flow | ||||
Autoren: |
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Datum: | 2005 | ||||
Erschienen in: | Journal of Aircraft | ||||
Open Access: | Nein | ||||
In SCOPUS: | Nein | ||||
In ISI Web of Science: | Ja | ||||
Band: | Vol. 42 | ||||
Seitenbereich: | Seiten 794-798 | ||||
Stichwörter: | flow control, transonic flow, drag reduction | ||||
DLR - Schwerpunkt: | Luftfahrt | ||||
DLR - Forschungsgebiet: | L ST - Starrflüglertechnologien | ||||
Standort: | Göttingen | ||||
Institute & Einrichtungen: | Institut für Aeroelastik |
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