Dietz, Guido (2007) Lifting-Surface Limit-Cycle Oscillations due to Transonic Flow. Goldstein Lecture 2007, 2007-11-14, Manchester, UK (Europe).
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Abstract
Results from flutter and forced-oscillation wind-tunnel experiments at flow conditions close to the transonic dip are presented. Flutter boundaries exhibiting a transonic dip were determined and limit-cycle oscillations (LCOs) were measured. The local energy exchange between the fluid and the structure during LCOs is examined and leads to the following findings: at supercritical Mach numbers below that of the transonic-dip minimum the presence of a shock-wave and its dynamics destabilizes the aeroelastic system such that the decreasing branch of the transonic dip develops. At higher Mach numbers the shock-wave motion has a stabilizing effect such that the flutter boundary increases to higher flutter-speed indices with increasing Mach number. Amplified oscillations near this branch of the flutter boundary obtain energy from the flow mainly due to the dynamics of a trailing-edge flow separation. A slight nonlinear amplitude dependency of the shock motion and a possibly occurring boundary-layer separation cause the amplitude limitation of the observed LCOs. The impact of the experimental findings at Reynolds-numbers of about 1.5 Mio. on the numerical simulation of these phenomena, and on future research at flight-relevant Reynolds-numbers is discussed.
Item URL in elib: | https://elib.dlr.de/51913/ | ||||||||
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Document Type: | Conference or Workshop Item (Speech) | ||||||||
Title: | Lifting-Surface Limit-Cycle Oscillations due to Transonic Flow | ||||||||
Authors: |
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Date: | 2007 | ||||||||
Open Access: | No | ||||||||
Gold Open Access: | No | ||||||||
In SCOPUS: | No | ||||||||
In ISI Web of Science: | No | ||||||||
Status: | Published | ||||||||
Keywords: | limit-cycle oscillation, transonic dip, flutter, supercritical airfoil | ||||||||
Event Title: | Goldstein Lecture 2007 | ||||||||
Event Location: | Manchester, UK (Europe) | ||||||||
Event Type: | international Conference | ||||||||
Event Date: | 14 November 2007 | ||||||||
Organizer: | Royal Aeronautical Society Manchester Branch / University of Manchester | ||||||||
HGF - Research field: | Aeronautics, Space and Transport | ||||||||
HGF - Program: | Aeronautics | ||||||||
HGF - Program Themes: | Aircraft Research (old) | ||||||||
DLR - Research area: | Aeronautics | ||||||||
DLR - Program: | L AR - Aircraft Research | ||||||||
DLR - Research theme (Project): | L - Flexible Aircraft (old) | ||||||||
Location: | Göttingen | ||||||||
Institutes and Institutions: | Institute of Aeroelasticity | ||||||||
Deposited By: | Erdmann, Daniela | ||||||||
Deposited On: | 20 Nov 2007 | ||||||||
Last Modified: | 24 Apr 2024 19:14 |
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