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Generation of unsteady CF-instability modes by vibrational and vibration-vortex localized receptivity mechanisms

Kachanov, Y. S. and Borodulin, V. I. and Ivanov, A. V. and Mischenko, D. A. and Örlü, R. and Hanifi, Ardeshir and Hein, Stefan (2018) Generation of unsteady CF-instability modes by vibrational and vibration-vortex localized receptivity mechanisms. In: AIP Conference Proceedings, 2027 (020010). American Institute of Physics. 19th International Conference on the Methods of Aerophysical Research (ICMAR), 13.-19. Aug. 2018, Novosibirsk, Russia. DOI: 10.1063/1.5065088

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Official URL: https://doi.org/10.1063/1.5065088

Abstract

The paper is based on results obtained within an international project ‘RECEPT’ of the European Framework Program FP7. The experiments were carried out in a three-dimensional boundary layer developing on an experimental model of a long-laminar-run swept airfoil (sweep angle of 35°). The model was mounted in a test section of the lowturbulence wind-tunnel MTL (KTH, Stockholm) at an angle of attack of −5° and equipped with sidewalls provided satisfaction of infinite-span conditions. The cross-flow (CF) instability modes were predominant in this case, while the Tollmien–Schlichting (TS) waves were suppressed by a favorable pressure gradient. The main measurements were carried out by means of hot-wire anemometry at conditions of excitation of fully controlled, unsteady surface and flow perturbations. These perturbations were excited by special sources: (1) a row of oscillating membranes and (2) a vibrating wire, at frequencies of fs and fv, respectively. A very good, quantitative agreement between the measured and calculated (by linear stability theory based on PSE approach) amplification curves was found at surface frequency fs. However, the evolution of the CF-modes excited at difference combination frequency fsv– = fs – fv turned out to be very much different from the theoretical one. Thorough analysis of the obtained results has shown that the only explanation of these discrepancies can be associated with presence of a distributed receptivity mechanism due to scattering of freestream vortices on the CF-instability waves excited by surface vibrations. Another unusual and unexpected phenomenon found in the present experiments is associated with anomalous amplification of difference combination modes with the zero spanwise wavenumbers E′. This phenomenon was observed in the flow, which is stable with respect to both CF- and TSwaves having E′ = 0 for all frequencies. There is no explanation of this finding at present.

Item URL in elib:https://elib.dlr.de/118590/
Document Type:Conference or Workshop Item (Speech)
Title:Generation of unsteady CF-instability modes by vibrational and vibration-vortex localized receptivity mechanisms
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Kachanov, Y. S.Institute of Theoretical and Applied Mechanics, Novosibirsk, 630090, RussiaUNSPECIFIED
Borodulin, V. I.Institute of Theoretical and Applied Mechanics, Novosibirsk, 630090, RussiaUNSPECIFIED
Ivanov, A. V.Institute of Theoretical and Applied Mechanics, Novosibirsk, 630090, RussiaUNSPECIFIED
Mischenko, D. A.Institute of Theoretical and Applied Mechanics, Novosibirsk, 630090, RussiaUNSPECIFIED
Örlü, R.KTH, Stockholm, SchwedenUNSPECIFIED
Hanifi, ArdeshirKTH StockholmUNSPECIFIED
Hein, StefanDLR GöttingenUNSPECIFIED
Date:2 November 2018
Journal or Publication Title:AIP Conference Proceedings
Refereed publication:No
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:Yes
Volume:2027
DOI :10.1063/1.5065088
Publisher:American Institute of Physics
Status:Published
Keywords:laminar-turbulent transition, three-dimensional boundary layer, EU project RECEPT
Event Title:19th International Conference on the Methods of Aerophysical Research (ICMAR)
Event Location:Novosibirsk, Russia
Event Type:international Conference
Event Dates:13.-19. Aug. 2018
Organizer:American Institute of Physics
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:fixed-wing aircraft
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Flight Physics
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > High Speed Configurations, GO
Deposited By: Hein, Dr.-Ing. Stefan
Deposited On:27 Sep 2018 13:43
Last Modified:04 Jan 2019 12:51

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