Schwarz, Clemens and Bauknecht, Andre and Mailänder, Stephan and Raffel, Markus (2019) Wake Characterization of a Free-Flying Model Helicopter in Ground Effect. Journal of the American Helicopter Society, 64 (1), pp. 1-16. American Helicopter Society. doi: 10.4050/JAHS.64.012010. ISSN 0002-8711.
Full text not available from this repository.
Official URL: https://doi.org/10.4050/JAHS.64.012010
Abstract
Measurements of the flow field around a free-flying model helicopter in ground effect were performed for both quasi-steady and unsteady maneuvering flights using stereoscopic particle image velocimetry. Changing flow patterns like recirculation and ground vortex flow were observed for forward flight at low advance ratios and found to be in good agreement with existing wind tunnel data. Parameters describing both general wake structures and single blade tip vortices 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 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" was observed, with circulation values up to six times higher than for a single blade tip vortex.
Item URL in elib: | https://elib.dlr.de/126152/ | ||||||||||||||||||||
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Document Type: | Article | ||||||||||||||||||||
Title: | Wake Characterization of a Free-Flying Model Helicopter in Ground Effect | ||||||||||||||||||||
Authors: |
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Date: | 11 January 2019 | ||||||||||||||||||||
Journal or Publication Title: | Journal of the American Helicopter Society | ||||||||||||||||||||
Refereed publication: | Yes | ||||||||||||||||||||
Open Access: | No | ||||||||||||||||||||
Gold Open Access: | No | ||||||||||||||||||||
In SCOPUS: | Yes | ||||||||||||||||||||
In ISI Web of Science: | Yes | ||||||||||||||||||||
Volume: | 64 | ||||||||||||||||||||
DOI: | 10.4050/JAHS.64.012010 | ||||||||||||||||||||
Page Range: | pp. 1-16 | ||||||||||||||||||||
Editors: |
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Publisher: | American Helicopter Society | ||||||||||||||||||||
ISSN: | 0002-8711 | ||||||||||||||||||||
Status: | Published | ||||||||||||||||||||
Keywords: | Particle Image Velocimetry (PIV), model helicopter, ground effect, maneuvering flight, free flight experiments, blade-tip vortex | ||||||||||||||||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||||||||||||||||
HGF - Program: | Aeronautics | ||||||||||||||||||||
HGF - Program Themes: | rotorcraft | ||||||||||||||||||||
DLR - Research area: | Aeronautics | ||||||||||||||||||||
DLR - Program: | L RR - Rotorcraft Research | ||||||||||||||||||||
DLR - Research theme (Project): | L - The Virtual Aerodynamic Rotorcraft (old) | ||||||||||||||||||||
Location: | Göttingen | ||||||||||||||||||||
Institutes and Institutions: | Institute for Aerodynamics and Flow Technology > Helicopter, GO | ||||||||||||||||||||
Deposited By: | Winkels, Elisabeth | ||||||||||||||||||||
Deposited On: | 24 Jan 2019 14:40 | ||||||||||||||||||||
Last Modified: | 31 Oct 2023 15:14 |
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