elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Kontakt | English
Schriftgröße: [-] Text [+]

The Reynolds number effect from subcritical to high transcritical on the steady and unsteady loading on a rough circular cylinder

Van Hinsberg, Nils Paul und Lückhof, Jan-Marcus und Nuhn, Johannes (2014) The Reynolds number effect from subcritical to high transcritical on the steady and unsteady loading on a rough circular cylinder. In: 9th European Conference on Structural Dynamics (EURODYN 2014) (ISBN: 978-972-752-166-1), Seiten 154-155. University of Porto. IX International Conference on Structural Dynamics, 30. Juni - 02. Juli 2014, Porto, Portugal. ISBN 978-972-752-166-1.

Dieses Archiv kann nicht den gesamten Text zur Verfügung stellen.

Kurzfassung

Force and surface pressure measurements on a 2D rough circular cylinder were carried out over a wide range of Reynolds numbers in the high-pressure wind tunnel in Göttingen. The Reynolds number spanned values from subcritical up to high transcritical 15×103 ≤ Re ≤ 12×10^6. The cylinder had a mean relative surface roughness of ks/D = 1.2×10^-3. By means of piezoelectric balances the unsteady lift and drag forces were measured. The mean surface pressure distribution was obtained with the use of 59 static surface pressure tabs at various span-wise and circumferential locations on the cylinder. Statistical analysis of the time-dependent forces, in combination with the mean surface pressures, provided information on the spatial organization of the flow field properties around the cylinder as function of the Reynolds number. In the critical Reynolds regime two discontinuities at two separate Reynolds numbers were observed. They were accompanied by critical fluctuations in the lift force and the formation of a separation bubble at each side of the cylinder. The discontinuous jumps were initialized by a downstream movement of the separation point and an upstream movement of the transition point. The asymmetric flow field in-between both critical Reynolds numbers led to a steady lift force that was cancelled again after passing the second critical Reynolds number. At the latter Reynolds number the width of the wake and CD were minimum. In the super- and transcritical flow states the boundary layer separations took place at about the apex of the cylinder. In comparison to the subcritical and critical regimes all measured flow field properties reached intermediate steady plateaus in the transcritical state. For the Strouhal number this plateaus was at St = 0.23, for the base pressure at Cp,base = -0.9 and for the drag coefficient at CD ≈ -0.84.

Dokumentart:Konferenzbeitrag (Vortrag)
Titel:The Reynolds number effect from subcritical to high transcritical on the steady and unsteady loading on a rough circular cylinder
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Van Hinsberg, Nils Paulnils.vanhinsberg@dlr.de
Lückhof, Jan-MarcusNICHT SPEZIFIZIERT
Nuhn, Johannesjohannes.nuhn@dlr.de
Datum:Juli 2014
Erschienen in:9th European Conference on Structural Dynamics (EURODYN 2014) (ISBN: 978-972-752-166-1)
Referierte Publikation:Ja
In ISI Web of Science:Nein
Seitenbereich:Seiten 154-155
Herausgeber:
HerausgeberInstitution und/oder E-Mail-Adresse der Herausgeber
Cunha, A.NICHT SPEZIFIZIERT
Caetano, E.NICHT SPEZIFIZIERT
Ribeiro, P.NICHT SPEZIFIZIERT
Müller, G.NICHT SPEZIFIZIERT
Verlag:University of Porto
ISBN:978-972-752-166-1
Status:veröffentlicht
Stichwörter:Rough Cylinder; high Reynolds number; Critical flow; Surface roughness; high-pressure Wind Tunnel
Veranstaltungstitel:IX International Conference on Structural Dynamics
Veranstaltungsort:Porto, Portugal
Veranstaltungsart:internationale Konferenz
Veranstaltungsdatum:30. Juni - 02. Juli 2014
HGF - Forschungsbereich:Luftfahrt, Raumfahrt und Verkehr
HGF - Programm:Luftfahrt
HGF - Programmthema:Flugzeuge
DLR - Schwerpunkt:Luftfahrt
DLR - Forschungsgebiet:L AR - Aircraft Research
DLR - Teilgebiet (Projekt, Vorhaben):L - Flexibles Flugzeug
Standort: Göttingen
Institute & Einrichtungen:Institut für Aeroelastik > Aeroelastische Experimente
Hinterlegt von: Dr. Ir. Nils van Hinsberg
Hinterlegt am:07 Aug 2014 13:33
Letzte Änderung:15 Jan 2015 09:34

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Copyright © 2008-2013 Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.