Schwarz, Clemens und Bauknecht, Andre und Mailänder, Stephan und Raffel, Markus (2018) Wake Characterization of a Free-Flying Model Helicopter in Ground Effect. AHS International 74th Annual Forum & Technology Display, 2018-05-14 - 2018-05-17, Phoenix, Arizona, USA.
Dieses Archiv kann nicht den Volltext zur Verfügung stellen.
Offizielle URL: http://vtol.org
Kurzfassung
Measurements of the flow field around a free-flying model helicopter in ground effect for both quasi-steady and unsteady maneuvering flights were performed using stereoscopic particle image velocimetry (PIV). The wake features for hover and forward flight at low advance ratios were characterized and changing flow patterns like recirculation and ground vortex flow were observed to be in good agreement with existing wind tunnel data. Parameters describing both general flow patterns and single blade tip vortices were extracted and showed significant dependence on the forward flight velocity. Landing approaches were performed and large vortical structures were observed close to the rotor disk, which contained high amounts of vorticity due to entrained blade tip vortices. The vortex structures developing for unsteady landing approaches contained distinctly higher velocities and momentum fluxes than expected from quasi-steady conditions at the same advance ratios. For a vertical takeoff maneuver with a rapid increase of collective pitch, the bundling of blade tip vortices into a "starting vortex" with circulation values up to 6 times higher than for a single blade tip vortex was observed. These results show the significance of experimental data on free-flying helicopters in unsteady maneuvering flight because the resulting flow fields cannot be predicted using steady-state experiments or simulations.
elib-URL des Eintrags: | https://elib.dlr.de/120402/ | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dokumentart: | Konferenzbeitrag (Vortrag) | ||||||||||||||||||||
Titel: | Wake Characterization of a Free-Flying Model Helicopter in Ground Effect | ||||||||||||||||||||
Autoren: |
| ||||||||||||||||||||
Datum: | 2018 | ||||||||||||||||||||
Referierte Publikation: | Ja | ||||||||||||||||||||
Open Access: | Nein | ||||||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||||||
In SCOPUS: | Nein | ||||||||||||||||||||
In ISI Web of Science: | Nein | ||||||||||||||||||||
Status: | veröffentlicht | ||||||||||||||||||||
Stichwörter: | Particle Image Velocimetry (PIV), Model Helicopter, Ground Effect, Maneuvering Flight, Free Flight Experiments, Blade-Tip Vortex | ||||||||||||||||||||
Veranstaltungstitel: | AHS International 74th Annual Forum & Technology Display | ||||||||||||||||||||
Veranstaltungsort: | Phoenix, Arizona, USA | ||||||||||||||||||||
Veranstaltungsart: | internationale Konferenz | ||||||||||||||||||||
Veranstaltungsbeginn: | 14 Mai 2018 | ||||||||||||||||||||
Veranstaltungsende: | 17 Mai 2018 | ||||||||||||||||||||
Veranstalter : | AHS International Inc. | ||||||||||||||||||||
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 | ||||||||||||||||||||
Hinterlegt von: | Winkels, Elisabeth | ||||||||||||||||||||
Hinterlegt am: | 15 Jun 2018 11:37 | ||||||||||||||||||||
Letzte Änderung: | 24 Apr 2024 20:24 |
Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags