Weiss, Armin und Wolf, C. Christian und Kaufmann, Kurt und Braukmann, Johannes N. und Heineck, James T. und Raffel, Markus (2020) Unsteady Boundary-Layer Transition Measurements and Computations on a Rotating Blade under Cyclic Pitch Conditions. Experiments in Fluids, 61 (2), Seiten 1-16. Springer Nature. doi: 10.1007/s00348-020-2899-7. ISSN 0723-4864.
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Offizielle URL: https://doi.org/10.1007/s00348-020-2899-7
Kurzfassung
The presented work tackles the lack of experimental investigations of unsteady laminar-turbulent boundary-layer transition on rotor blades at cyclic pitch actuation, which are important for accurate performance predictions of helicopters in forward flight. Unsteady transition positions were measured on the blade suction side of a four-bladed subscale rotor by means of non-intrusive differential infrared thermography (DIT). Experiments were conducted at different rotation rates corresponding to Mach and Reynolds numbers at 75% rotor radius of up to M_75=0.21 and Re_75 =3.3×10^5 and with varying cyclic blade pitch settings. The setup allowed transition to be measured across the outer 54% of the rotor radius. For comparison, transition was also measured using conventional infrared thermography for steady cases with collective pitch settings only. The study is complemented by numerical simulations including boundary-layer transition modeling based on semi-empirical criteria. DIT results reveal the upstream and downstream motion of boundary-layer transition during upstroke and downstroke, a reasonable comparison to experimental results obtained using the already established sigma*c_p method, and noticeable agreement with numerical simulations. The result is the first systematic study of unsteady boundary-layer transition on a rotor suction side by means of DIT including a comparison to numerical computations.
elib-URL des Eintrags: | https://elib.dlr.de/128642/ | ||||||||||||||||||||||||||||
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Dokumentart: | Zeitschriftenbeitrag | ||||||||||||||||||||||||||||
Zusätzliche Informationen: | Article 61 | ||||||||||||||||||||||||||||
Titel: | Unsteady Boundary-Layer Transition Measurements and Computations on a Rotating Blade under Cyclic Pitch Conditions | ||||||||||||||||||||||||||||
Autoren: |
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Datum: | 24 April 2020 | ||||||||||||||||||||||||||||
Erschienen in: | Experiments in Fluids | ||||||||||||||||||||||||||||
Referierte Publikation: | Ja | ||||||||||||||||||||||||||||
Open Access: | Ja | ||||||||||||||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||||||||||||||
In SCOPUS: | Ja | ||||||||||||||||||||||||||||
In ISI Web of Science: | Ja | ||||||||||||||||||||||||||||
Band: | 61 | ||||||||||||||||||||||||||||
DOI: | 10.1007/s00348-020-2899-7 | ||||||||||||||||||||||||||||
Seitenbereich: | Seiten 1-16 | ||||||||||||||||||||||||||||
Herausgeber: |
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Verlag: | Springer Nature | ||||||||||||||||||||||||||||
ISSN: | 0723-4864 | ||||||||||||||||||||||||||||
Status: | veröffentlicht | ||||||||||||||||||||||||||||
Stichwörter: | unsteady boundary-layer transition, rotor blades, differential infrared-thermography (DIT), semi-empirical transition modeling, e^N–method | ||||||||||||||||||||||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||||||||||||||||||||||
HGF - Programm: | Luftfahrt | ||||||||||||||||||||||||||||
HGF - Programmthema: | Hubschrauber | ||||||||||||||||||||||||||||
DLR - Schwerpunkt: | Luftfahrt | ||||||||||||||||||||||||||||
DLR - Forschungsgebiet: | L RR - Rotorcraft Research | ||||||||||||||||||||||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | L - Der virtuelle Drehflügler (alt) | ||||||||||||||||||||||||||||
Standort: | Göttingen | ||||||||||||||||||||||||||||
Institute & Einrichtungen: | Institut für Aerodynamik und Strömungstechnik > Hubschrauber, GO Institut für Aerodynamik und Strömungstechnik > Experimentelle Verfahren, GO | ||||||||||||||||||||||||||||
Hinterlegt von: | Winkels, Elisabeth | ||||||||||||||||||||||||||||
Hinterlegt am: | 19 Feb 2020 11:52 | ||||||||||||||||||||||||||||
Letzte Änderung: | 23 Okt 2023 12:39 |
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